DOGAMI Special Paper 35, Tsunami Warning Systems and Procedures

Oregon Department of Geology and Mineral Industries Special Paper 35

Tsunami Warning Systems and Procedures

Guidance for Local Officials Oregon Emergency Management and the Oregon Department of Geology and Mineral Industries

2001 Oregon Department of Geology and Mineral Industries Special Papers, ISSN 0278-3703 Published in conformance with ORS 516.030

For copies of this publication, or other information about tsunamis, including tsunami hazard maps for the Oregon coast, contact: Nature of the Northwest Information Center 800 NE Oregon Street #5 Portland, Oregon 97232 (503) 872-2750 www.naturenw.org Special Paper 35

Tsunami Warning Systems and Procedures: Guidance for Local Officials

Prepared for the National Tsunami Hazard Mitigation Program by Oregon Emergency Management and Oregon Department of Geology and Mineral Industries

2001

STATE OF OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES John D. Beaulieu, State Geologist “The greatest enemy

of communication

is the illusion that it has taken place.”

Pierre Martineau Table of Contents

Executive Summary ...... v Preface and Acknowledgments ...... vi Introduction ...... 1 Section 1: General Tsunami Information ...... 2 Causes and geographic locations of tsunamis ...... 2 Characteristics of tsunamis ...... 2 Local versus distant tsunamis ...... 4 Tsunamis that affect the United States and Canada ...... 4 Section 2: Tsunami Warning Centers ...... 6 West Coast/Pacific Tsunami Warning Center (WC/ATWC) ...... 6 Pacific Tsunami Warning Center (PTWC) ...... 8 Chile Warning Center ...... 8 Improvements in tsunami warning ...... 8 Section 3: Established Evacuation Notification Systems ...... 11 Japan system ...... 11 Hawaii system ...... 12 Other systems ...... 13 Section 4: Types of Notification Systems and Procedures ...... 15 Introduction ...... 15 Available notification systems and procedures ...... 17 Sirens ...... 17 Telephones ...... 20 NOAA weather radios ...... 21 Emergency Alert System ...... 22 Emergency Managers Weather Information Network ...... 23 AlaskAlert ...... 24 Miscellaneous systems ...... 25 Conclusions ...... 27 References ...... 30 Acronyms ...... 30 Appendix I: Siren Details ...... 32 Appendix II: Siren Manufacturers ...... 37 Appendix III: Tsunami Warning Workshop Summary ...... 37

Special Paper 35: Tsunami Warning Systems and Procedures page iii Pictured is an electronic siren station of the Cannon Beach Rural Fire Protection District Community Warning System. This unit is a Whelen WS2000-16 with Public Address feature. The unit is comprised of sixteen re-entrant speakers, four speakers aiming at each compass quadrant. The effective range is approximately 2,400 feet in each direction. Each station operates on 24 VDC supplied by four 6 VDC deep cycle storage batteries maintained by a solar charger entirely independent of commercial power. Station operation is radio-controlled from the district's main fire station using pre-recorded announcements (Sony MiniDisc format). The system operator can also make special announcements by microphone through all the stations simultaneously or any single station. Controls at the main fire station have automatic auxiliary power if commercial power fails.

page iv Special Paper 35: Tsunami Warning Systems and Procedures Executive Summary and NOAA Weather Radio. In the case of a local tsunami, the warning is usually the earthquake. Tsunamis are one of the most destructive forces in However, notification by local systems is also nature and can cause much loss of life, injury, and needed to reinforce evacuation orders, provided property damage. Tsunamis are usually produced the systems are functional after the earthquake. by the uplift of the sea floor from a large magnitude subduction zone earthquake. Most tsunamis There are a variety of local evacuation notification are created in the Pacific Ocean, because the systems. They include sirens, NOAA weather largest number of subduction zones is found radio, the Emergency Alert System, telephones, there. The effects of a tsunami can be local or dis- the Emergency Managers Weather Information tant. The last destructive tsunami to significantly Network, and others. Each system has benefits affect the United States was caused by the 1964 and drawbacks, which are discussed in detail in Alaskan earthquake. There was damage and loss this document. of life locally in Alaska, and distantly in Hawaii, The system that an area uses depends on several California, Oregon, and Washington. factors, including the nature of the population Injury and loss of life can be minimized if coastal (residents vs. non-residents), budget, and geo- populations are warned that a tsunami is graphic location. There should be complete cover- approaching. Coastal populations can be notified age, redundancy, and seamless meshing of new of a distant tsunami by a combination of: and existing systems. Regardless of the system, it Tsunami warnings from the Tsunami Warning is critical that there be consistency in its applica- Centers in Hawaii and Alaska; and evacuation tion and message, as well as consistent and con- notifications from local systems, such as sirens tinuous education about the alerts.

Special Paper 35: Tsunami Warning Systems and Procedures page v Preface and Acknowledgments Stuart Weinstein, Pacific Tsunami Warning Center These guidelines were prepared by Oregon Emergency Management for the National Lt. Al Yelvington, U.S. Coast Guard Tsunami Hazard Mitigation Program under a Alaska contract awarded to the Oregon Department of Geology and Mineral Industries. The National John Alcantra, Kenai Borough Emergency Tsunami Hazard Mitigation Program (NTHMP) is Management funded by the National Oceanographic and Gary Brown and R. Scott Simmons, State Atmospheric Administration (NOAA). It is Division of Emergency Services steered by a group made up of representatives from NOAA, the United States Geological Survey California (USGS), the Federal Emergency Management George Brown, San Luis Obispo Office of Agency (FEMA), the National Science Foundation Emergency Services (NSF), and the five Pacific coastal states (Alaska, California, Hawaii, Oregon, and Washington). Lori Dengler, Humboldt State University The National Tsunami Hazard Mitigation Hawaii Program was created to reduce the impact of Norman Ogasawara, George Burnett, and tsunamis through: Brian Yanagi, Hawaii Civil Defense 1. Warning guidance - deploy tsunami detec- Oregon tion buoys and improve seismic systems Al Aya, Cannon Beach Rural Fire Protection 2. Mitigation – develop tsunami hazard mitiga- District tion programs and projects Mike Franzen, Portland Fire Bureau 3. Hazard assessment – produce tsunami inundation maps. Galen Howard, Lane County Council of Governments For more information on the program, visit the web site at www.pmel.noaa.gov/tsunami-hazard. George Priest, Oregon Department of Geology and Mineral Industries This document is the result of the efforts of many individuals representing several organizations. Wayne Stinson, Douglas County Emergency Special thanks to the following for their review, Management comments, and contributions: Washington Dan Keeton, National Weather Service John Vollmer, George Crawford, and Sheryl David Oppenheimer, United States Geological Jardine, Washington State Emergency Survey, Menlo Park Management Division Tom Sokolowski, West Coast/Alaska Tsunami Warning Center

page vi Special Paper 35: Tsunami Warning Systems and Procedures Introduction Several factors must be taken into consideration when making decisions about what system is best The main purpose of this document is to provide for an area: state and local officials with information on various local tsunami warning systems and proce- 1. The size and layout of the area. dures, and to assist coastal jurisdictions with A. Is it compact or spread out? planning and developing warning systems and procedures for their own areas. This document B. Is it located adjacent to a beach or was the basis for discussion of tsunami warning adjacent to a harbor? systems at a Tsunami Warning Workshop on May 2. The make up and activities of the population 14 and 15, 2001 in Portland and should be consid- to be served. ered a work in progress. The workshop summary, which includes five consensus recommendations, A. Is the town mostly retirees? is found in Appendix III. B. Is there a large transient population? Systems are the hardware to alert people to evacu- C. Are they mainly on the beach or in/near ate to high ground. These systems can also be the bay? used for other hazards, prompting people to turn on the radio or television for information on 3. The financial resources of the community. whether to evacuate or take other protective 4. The existing notification systems in each action. Tsunami alerts should be incorporated jurisdiction as well as in adjacent cities, coun- into a jurisdiction’s all-hazards warning system. ties, boroughs and states. Is there a need for Procedures are the protocols followed to activate system consistency within a jurisdiction and the systems. There are two types of warning sys- between boroughs, counties, and states? tems and procedures described in this document: This document provides you with information to One is the warning from the Tsunami Warning make these decisions. It consists of four major sec- Centers in Hawaii and Alaska that a tsunami has tions. been generated; the other is the warning that evacuation from low-lying areas is necessary. To Section 1 provides a brief overview of tsunamis avoid confusion between the two, a warning will causes and characteristics. refer to the message from the Tsunami Warning Section 2 describes the Pacific, West Coast/Alaska, Centers in Hawaii and Alaska and a notification and Chile Tsunami Warning Centers and their will refer to the call for evacuation. For example, roles in the tsunami detection, warning and local coastal counties can receive a tsunami warning notification process. from the West Coast/Alaska Tsunami Warning Center (WC/ATWC) then activate a tsunami Section 3 describes briefly existing notification sys- evacuation notification system, such as sirens. tems from different countries and states: Japan, Hawaii, Alaska, California, Oregon, and There is no one tsunami evacuation notification Washington. system that is best for all coastal areas. All systems have their pros and cons, which are Section 4 describes in detail various evacuation addressed at length in this document. Different notification systems and their associated proce- communities have distinct characteristics and dures. needs. Each coastal jurisdiction must decide what system to use, ideally with assistance from the state and federal governments.

Special Paper 35: Tsunami Warning Systems and Procedures page 1 Section 1: General Tsunami Information Causes and geographic locations of tsunamis A tsunami is a series of ocean waves generated by the sudden displacement of large volumes of water due to: 1. The vertical movement of the sea floor as a result of large thrust-type submarine earthquakes (called subduction zone earthquakes), 2. Submarine volcanic eruptions, 3. Meteor impacts, or 4. Coastal (land-based or submarine) landslides. Tsunamis usually occur in zones of strong seismic activity. The most active tsunami zone is the Figure 2. Tsunami arrival chronograph (Pacific Pacific Ocean, surrounded by the Ring of Fire Disaster Center) (contours in hours). (Figure 1). The Ring of Fire features active volcanoes, rugged coastal terrain, and submarine sub- far removed from the source. Their speed duction zones, such as the Alaskan/Aleutian off depends on the depth of water. In the deep and Alaska and the Cascadia off the Pacific Northwest open ocean, waves can reach speeds of 800 kilo- United States. Tsunamis are usually associated meters per hour (approximately 480 mph or as with subduction zone earthquakes in the Pacific fast a commercial jetliner). The waves slow down Ocean, although rare, destructive tsunamis have in shallow water. also occurred in the Atlantic Ocean and The height of the waves in deep water may range Caribbean Sea. In 1929 a submarine landslide in from 30 to 60 centimeters (1-2 feet), producing the Grand Banks off Canada sent destructive only a gentle rise and fall of the sea surface, and waves into the eastern seaboard. are usually unnoticed. As a tsunami wave enters Characteristics of tsunamis the shallow waters of a coastline, its speed decreases rapidly. This causes the front of the Tsunamis travel outward in all directions from wave to slow down relative to the back, produc- the source area (Figure 2). The tsunami can strike ing a greater height as the water piles up onto the coastal areas with devastating effect even in areas coastline. The configuration of the coastline, shape of the ocean floor, and characteristics of the advancing waves play an important role in the destructiveness of the wave. A wave may be of negligible size at one point on a coast and of much larger size at other points. Narrow bays and inlets may cause funneling effects that magnify the initial and subsequent waves. Upon striking a coast, the wave reflects (bounces seaward) and then turns back toward the coast as a series of waves. Thus, every tsunami creates numerous waves, which may continue to arrive for hours after the Figure 1. The Pacific Ring of Fire. first wave. page 2 Special Paper 35: Tsunami Warning Systems and Procedures Figure 3. Cresting wave entering Hilo in 1946.

Figure 4. Fast rising tide in Hawaii (1957).

Figure 5. Tsunami bore heading up a river in Hawaii.

Special Paper 35: Tsunami Warning Systems and Procedures page 3 The first visible indication of an approaching have greater destructive potential, because the tsunami may be the rapid retreat of the ocean. In initial waves are larger and more area is affected. some instances, particularly with local tsunamis, For example, a tsunami generated by a Mw 9.5 the water may initially rise. The force and subduction zone earthquake off southern Chile on destructive effects of tsunamis should not be May 22, 1960 caused death and destruction from underestimated. Chile, to Hawaii, Japan and the Philippines. The Tsunamis attack the coast either as a cresting Pacific Northwest was also affected by the Chile wave, a fast rising tide, or bore (Figures 3-5). At tsunami, but suffered more damage from a simi- some locations, the advancing turbulent front will lar tsunami produced by a subduction zone earth- be the most destructive part of the wave. In other quake off Alaska on March 27, 1964. Since Pacific- situations, the greatest damage will be caused by wide tsunamis strike multiple areas, most areas of the outflow of water back to the sea between the Pacific basin experience many more distant tsunami surges, sweeping all before it and under- tsunamis than locally derived ones. mining roads, buildings and other works. Ships, Tsunamis that affect the United States unless moved away from shore, may be dashed and Canada against breakwaters, wharves and other craft, or Zones that can cause local and distant tsunamis be washed ashore and left grounded after the that would affect the United States and Canada withdrawal of the seawater. A significant addi- include: tional problem occurs when boats that are on moorings can not refloat fast enough when the 1. The Cascadia Subduction Zone and Alaskan- water returns over their sterns. Aleutian Subduction Zone Local versus distant tsunamis 2. Other zones that could produce a potentially damaging tsunami are Chile, Peru, For notification system purposes, tsunamis are Kamchatka, Japan, and the Kuril Islands. categorized as local or distant, depending on how There are also minor zones off the coast of long it takes the tsunami to arrive at the area of Hawaii and California that could produce concern. A local tsunami can arrive at the coast in potentially destructive but localized minutes, while a distant tsunami may arrive sev- tsunamis. The Hawaiian Islands consist of eral hours after it was generated. A local tsunami active, inactive, and dormant volcanoes. could be produced by a very local event affecting Offshore eruptions and landslides off Hawaii only a very limited area of the coast. An example and tectonic activity and landslides off is the July 9, 1958 Lituya Bay, Alaska tsunami southern California can cause tsunamis that which was caused by a local landslide and creat- arrive on their shorelines within minutes. ed wave run-ups as high as 525 meters (approximately 1,700 feet). Areas affected by regional Cascadia Subduction Zone (CSZ) events are generally smaller than those affecting The Cascadia Subduction Zone (CSZ) lies to the the entire Pacific. Because of either a lower level west of the California, Oregon, Washington, and of energy released or the geographical configura- British Columbia coasts (Figure 6). CSZ earth- tion of the region, the tsunami’s spread is inhibit- quakes have the potential to generate large ed. An example of a regional tsunami is the one tsunamis that can affect the entire Pacific Ocean. that originated off the coast of the Philippines, Local arrival times for these events can be from 5 August 16, 1976, in which approximately 8,000 to 30 minutes. people were killed. Alaskan-Aleutian Subduction Zone A local tsunami could also be produced by a The Alaskan-Aleutian Subduction Zone extends major event that would have regional or Pacific- from southeastern Alaska to the westernmost tip wide effects, and thus be considered both a local of the Aleutian Islands (Figure 7). The 1946 earth- and distant tsunami. For example, a tsunami gen- quake and tsunami, which resulted in the found- erated off the coast of Chile is local to Chile but ing of the Tsunami Warning Center, occurred just distant to the United States and Japan. Loss of life off Unimak Island in the Aleutians. The first wave and property is most severe closest to the source arrived in less than one hour and totally in an event that generates a Pacific-wide tsunami. destroyed the Coast Guard lighthouse at Scotch Pacific-wide tsunamis are much less frequent but Cap with a loss of all hands. page 4 Special Paper 35: Tsunami Warning Systems and Procedures Figure 6. Cascadia Subduction Zone in map view and cross section.

Figure 7. Alaskan-Aleutian Subduction Zone (numbers refer to potential rupture segments).

Special Paper 35: Tsunami Warning Systems and Procedures page 5 Section 2: Tsunami Warning Centers The Tsunami Warning Centers, operated by the National Oceanic and Atmospheric Administration (NOAA), have the primary responsibility to issue tsunami notices within their areas of responsibility, especially through emergency officials. Coordinating and managing evacuations (evacuation notification) is the responsibility of local emergency personnel. In other words, the Warning Centers warn emergency officials; local emergency officials notify and Figure 8. Warning center locations. direct the local evacuation efforts. expanded to cover the entire WC/ATWC AOR in There are currently two Tsunami Warning the event of a major tsunami. Centers for the United States and Canada (figure 8): Watch: An alert issued to areas outside the warned area. The area included in the watch is based on 1. West Coast/Alaska Tsunami Warning Center the magnitude of the earthquake. For earthquakes (WC/ATWC) over M7.0, the watch area is 1 hour tsunami travel 2. Pacific Tsunami Warning Center (PTWC) time from the warning zone. For earthquakes over M7.5, the watch area is 3 hours tsunami trav- The Chile Warning System will also be discussed. el time from the warning zone. The watch will The Chile system has similarities to the either be upgraded to a warning in subsequent WC/ATWC and PTWC, but also a few major dif- bulletins or will be cancelled, depending on the ferences. severity of the tsunami. West Coast/Alaskan Tsunami Warning Advisory: A message issued when a major quake has Center (WC/ATWC) occurred outside the AOR prompting PTWC to issue a The WC/ATWC, located in Palmer, Alaska, has tsunami warning, and the event is either far enough the sole responsibility for issuing tsunami warn- away so that no AOR region is within a watch/warnings to coastal locations of California, Oregon, ing OR the tsunami poses no threat to the AOR. Washington, British Columbia, and Alaska. Advisories are updated hourly as PTWC issues Tsunami warnings, watches, advisories, informa- bulletins and can be upgraded to a watch or tion bulletins, and messages are issued based on warning if necessary. earthquake location and magnitude. Bulletins Information Bulletin: Bulletins issued for earth- issued by the WC/ATWC are defined below: quakes less than warning threshold, but greater than Warning: Indicates a tsunami is imminent and M6.5 which are not likely to trigger a destructive coastal locations in the warned area should prepare for tsunami. Unless further information is gathered on flooding. The initial warning is typically based on tsunami generation, only one Information Bulletin seismic information alone. Earthquakes within the is issued for an event. WC/ATWC area of responsibility (AOR) over Information Message: A message issued for earth- Magnitude (M)7.0 trigger a warning covering the quakes below M6.5 strongly felt along coastal areas of coastal regions within 2 hours tsunami travel time the AOR. Its purpose is to rapidly inform resi- from the epicenter. When the magnitude is over dents that there is no tsunami danger. 7.5, the warned area is increased to 3 hours tsunami travel time. For earthquakes outside the All initial messages are based solely on seismic WC/ATWC AOR, warnings are only issued for data. The WC/ATWC has developed a state-of- earthquakes greater than M7.5 and for those loca- the-art earthquake processing system (EarlyBird) tions within 3 hours tsunami travel time of the which automatically locates and sizes potentially leading edge of the wave. As tidal gage data tsunami-producing events worldwide. showing the tsunami is recorded, the warning Geophysicists can easily interact with the auto- will be cancelled, expanded incrementally, or matic results so that reviewed information is page 6 Special Paper 35: Tsunami Warning Systems and Procedures issued in tsunami messages. Epicenter locations FEMA, military contacts, US Coast Guard, and are normally computed within 2 minutes of the NWS offices. Secondary methods of message dis- origin time for earthquakes within the AOR. semination are direct phone contacts, e-mail mes- Magnitudes for earthquakes less than M6 are sages, home page updates (wcatwc.gov), and an computed at the same time as the location, while experimental pager notification system. for larger earthquakes it takes a few more min- Since 1980, the average time it has taken utes to compute an accurate magnitude. Earth- WC/ATWC to issue a tsunami warning has been quakes outside the AOR are located within sec- 11 minutes. With the recent installation of new onds after enough P-wave arrivals have been data communication systems, instruments, and recorded to accurately locate the event. This time processing techniques, this time should decrease. varies from about 6 minutes for Kamchatka For example, after the December 6, 1999 M6.9 quakes to 12 minutes for southwest Pacific quakes. Kodiak Island earthquake, a tsunami information After a tsunami bulletin is issued, tide gage data bulletin was issued 3 minutes after the earth- is monitored to determine whether or not a tsuna- quake’s origin time. mi has occurred. The tsunami severity as recorded on the gages indicates to the WC/ATWC whether What will the warning centers tell us? to continue and expand the warning or cancel. If The warning centers provide the following infor- no tsunami has reached a gage within an hour of mation when there is a potentially tsunami-gener- the first message, a second message will be issued ating earthquake within their AOR: as a precaution which expands the warning area. 1. Warning or no warning There is no way to accurately predict wave heights 2. Limits of areas in warning and watch for a local tsunami generated near the source zone of an earthquake. Difficulties in determining the 3. Location, size, and time of event exact source mechanism, secondary tsunami gen- 4. Evaluation of event; has the tsunami been eration sources, and the lack of time between tsu- verified or not nami generation and impact at the nearest coastal 5. Recorded wave heights if there were any locations make an accurate prediction impossible. However, the WC/ATWC has made great improve- 6. Estimated times of tsunami arrival ments in estimating tsunami heights outside the 7. What action has the other center taken source zone. Based on pre-computed tsunami 8. When to expect the next message models and observed tsunami heights, an estimate of tsunami height can be made for locations along All warning message sequences will have a final the North American coast outside the source region. bulletin. This could be a cancellation when it is apparent the danger is minimal. It could be a final Tsunami bulletins are issued over several differ- supplement, issued when there is a danger to a ent communication systems. Primary paths are: centers’ entire area of responsibility (AOR). This verbal warnings over the National Warning supplement states a potentially damaging tsuna- System network (NAWAS), hard-copy over the mi has been generated. It also states that the all NOAA Weather Wire, and hard-copy over the clear determination must be made by local offi- FAA NADIN2 communication system. These sys- cials since there is such a great difference in how tems activate the National Weather Service a tsunami can affect different locations. (NWS) Emergency Management Weather Information Network (EMWIN) and the NOAA What won’t the warning centers tell us? Weather Radio. Also, the Emergency Alert System (EAS) is activated through the NWS forecast The warning centers do not provide the following offices and/or the state departments of emergen- information: cy services. However, locals often determine 1. When to evacuate which messages and associated message type 2. How to evacuate headers will activate the local EAS Decoders. So not all tsunami messages will activate the local 3. Where to evacuate EAS system, even though they are generated by 4. Expected wave heights the NWS. Primary sites to receive tsunami bul- 5. All clear determination after a large tsunami letins are the state emergency service offices, has occurred

Special Paper 35: Tsunami Warning Systems and Procedures page 7 Pacific Tsunami Warning Center (PTWC) evaluate local offshore earthquakes for tsunami generating potential and transmit the warning to The PTWC, located in Ewa Beach, Hawaii, is local officials. Locally produced tsunamis could responsible for Hawaii and the rest of the Pacific arrive on shore in 5 to 30 minutes. Therefore, a Rim nations, including Mexico and South Amer- very rapid assessment and warning is required to ica. The PTWC is responsible for monitoring seis- trigger evacuation notification systems to supple- mic events throughout the Pacific Ocean. It works ment evacuation activity triggered by the ground with regional and national centers to monitor shaking. seismological and tidal stations to evaluate earthquakes for their potential to generate tsunamis. After nine months of testing, the average When there is a regional or Pacific-wide event, response time was two minutes. With reliable the PTWC works notification systems closely with the West in place, evacuation Coast/Alaska notification based on Tsunami Warning the rapid warning Center to ensure would be timely and warnings are consis- save lives. To with- tent. stand strong ground shaking, the equip- The PTWC also ment is durable and works closely with self-powered by the International uninterruptable Tsunami Information sources. Hardware Center (ITIC), which costs for the most is responsible for basic THRUST sys- monitoring warning tem were $15,000 in activities in the 1986 US dollars. Pacific, recommending improvements in Improvements in them, assisting mem- tsunami warning ber states in estab- Tsunami warning lishing warning sys- technology is contin- tems, and fostering ually improving, research. reflecting changes in The general criteria technology, growing the PTWC uses to awareness that accu- determine the tsuna- rate tsunami predic- mi producing poten- tion requires inter- tial of an earthquake national teamwork, and the types of mes- and increased local sages sent (warning, Figure 9. Tsunami warning buoy configuration. interest in improving watches, advisory tsunami prediction. bulletins) are essentially the same as the ATWC, Following are examples of recent developments. although the text of the messages and the proto- Deep Ocean Assessment and Reporting of Tsunamis col for local tsunamis may be slightly different. (DART) The major difference is their areas of responsibility. DART is a real time distant tsunami detector system developed by NOAA’s Pacific Marine Chile Warning Center Environmental Laboratory (PMEL). PMEL is THRUST (Tsunami Hazards Reduction Utilizing installing the systems (buoys and bottom sensors, Systems Technology) is a satellite-based tsunami see Figure 9) in the open ocean off Alaska, warning system that was developed by the Oregon, and Washington. The system uses sensi- NOAA Pacific Marine Laboratory and tested in tive water-depth detection equipment, underwa- Chile in the late 1980s. It is designed to rapidly ter modems, satellite telemetry, and advanced sig- page 8 Special Paper 35: Tsunami Warning Systems and Procedures Hilo tsunami on May 23, 1960 Of Adults in Hazard Zone Hearing Sirens 41% Evacuated

Figure 10. Actual figures from Hilo, Hawaii tsunami on Monday, May 23, 1960.

59% Did Not Evacuate

Hypothetical Cannon Beach Scenario: Of the 6,344 Adults in the Hazard Zone Hearing Sirens 2,608 or 41% Evacuated

Figure 11. Applying Hilo May, 1960 experience to a hypothetical at-risk peak population in Cannon Beach, Oregon.

3,736 or 59% Did Not Evacuate

Special Paper 35: Tsunami Warning Systems and Procedures page 9 nal processing to detect and measure tsunami information between the various components. waves in the open ocean. Its purpose is to confirm The transfer of information is becoming increas- that a potentially destructive tsunami has been ingly rapid and continuous through technologies produced. The ultimate goal is to reduce the num- which include the Internet, telephones, modems, ber of false alarms in the Pacific Northwest and radios, local-area networks (LANs) and wide-area Hawaii. networks (WANs). False alarms, if numerous, may cause people to Real time Earthquake Notification Systems ignore an actual evacuation notification. Even in Rapid earthquake notification systems are located areas like Hawaii, which has a long history of in California, Oregon, and Washington: CUBE destructive tsunamis, sirens have been ignored. A (Caltech USGS Broadcast of Earthquakes), REDI study (Lachman and others, 1961) showed that (Rapid Earthquake Data Integration), and RACE during the May, 1960 tsunami, only 42% of the (Rapid Alert Cascadia Earthquake). These sys- people who heard the alarm evacuated (Figure tems provide preliminary earthquake epicenters 10). Many Hilo residents knew about the oncom- and magnitudes (above a defined threshold) with- ing Chilean tsunami at least 10 hours ahead of in minutes of the earthquake’s occurrence. time. More than 4 hours ahead of the first wave, Knowledge of the location and magnitude could Civil Defense sirens, meant as evacuation notifica- be used by emergency managers to halt evacuation, sounded for twenty minutes. Of an estimat- tion that was initiated by inland ground shaking. ed 1,000-1,200 adults in the hazard area, 61 were For example, the 1999 M5.9 Satsop earthquake killed and several hundred severely injured. was centered approximately 30 miles inland from Figure 11 applies the Hilo experience to a peak the coast in Washington. It was strongly felt in population in Cannon Beach. The Cannon Beach coastal areas and caused 50-100 people to evacu- Fire District community warning system in this ate to high ground. scenario would be generic sirens instead of the actual system in use. The actual system includes Later Wave Forecast Methodology (LWFM) electronic sirens that alert people in hazard areas LWFM is a statistical model that uses coastal tide and public address instructions that say what the gage observations to forecast the extreme heights emergency is, what to do about it, and when to of later waves in Pacific-wide tsunamis for loca- do it. tions in the vicinity of real-time reporting tide It is estimated that in a significant tsunami, more gages. The forecast method is based on a study of than half the people remaining in the hazard zone six observed Pacific-wide tsunamis, including the will be buried in wreckage and one quarter 1960 Chile and 1964 Alaska. It was developed by injured or killed. Using the Hilo estimate of sig- NOAA’s Tsunami Inundation Mapping Effort nificant casualties in a tsunami hazard zone for (TIME) and the software was delivered to Cannon Beach, more than half (>1,869) of the peo- WC/ATWC and PTWC. ple remaining in the Cannon Beach Fire District Pacific-wide tsunamis remain dangerous for hazard zone would be buried in wreckage and many hours. The first waves may or may not be one quarter (934) injured or killed. the highest waves. The time interval between wave peaks varies from 5-40 minutes. Later wave Consolidated Reporting of Earthquakes and Tsunamis trains threaten rescue and recovery operations, (CREST) especially when they arrive at high tide. Such CREST is a project funded through the National waves also endanger vessels in shallow water. Tsunami Hazard Mitigation Program. Its purpose Emergency managers need wave height forecasts is to upgrade regional seismic networks in to help guide rescue and recovery operations. Alaska, Washington, Oregon, California, and They also need them to decide when to issue the Hawaii and provide near real-time seismic infor- all clear. By combining wave height and tidal mation (location, magnitude, and continuous seis- forecast information, emergency managers could mic waveforms) from these networks to the decide when to allow emergency personnel to tsunami warning centers. CREST facilities are enter low-lying areas. If a low wave forecast is linked by real time communication, including coupled with a low tide, the dangers from the dedicated circuits with routers and satellite tsunami are reduced and emergency personnel transceivers, to quickly and reliably exchange could be deployed if needed. page 10 Special Paper 35: Tsunami Warning Systems and Procedures Section 3: Established Tsunami through the Central Automated Data Editing and Evacuation Notification Systems Switching System (C-ADESS). The tsunami warning centers discussed in Section There are three types of tsunami bulletins (warn- 2 issue only warnings. The tsunami evacuation ing, watch, information). The bulletins are well notification systems discussed in this section are defined and are similar to those of the United the next step. They are used to notify the general States Tsunami Warning Centers. public that evacuation is necessary after a warn- Ministries and agencies at the national level that ing is received from the center. Notification sys- contribute to disaster mitigation are linked tems tend to be either more advanced and coordi- together in the Central Emergency Management nated such as the Japan, Hawaii, and Chile sys- Communication Network (CEMCN). Members of tems (discussed in detail below) or less advanced the CEMCN include Ministry of Construction, and coordinated such as those found in the states Tokyo Electric Power, and Nippon Broadcasting of Alaska, California, Oregon, and Washington. Corporation. Once notified by the Japanese Advanced systems incorporate all regions of the Meteorological Agency, the CEMCN transmits country or state into the system. Although tsunami bulletins to their own regional offices. Alaska, California, Washington, and Oregon do Redundancy is built into the Japanese system, so contain jurisdictions with advanced and coordi- no one will be missed. nated systems, such as Kenai Borough in Alaska and Cannon Beach in Oregon, the entire state is The prefecture receives the bulletin at the same not one coordinated system and therefore they time as the CMCN. The prefecture then transmits are not considered advanced. the bulletin to the local governments (cities, towns) for action. Japan System The following are local notification methods: Japan is an island nation that is exposed to frequent seismic activity and tsunami risks. Like Simultaneous Announcement Wireless System Alaska and the Pacific Northwest, Japan is located (SAWS) near an active subduction zone. However, Japan SAWS is a dedicated system of transmitters and experiences significantly more tsunamis than the receivers installed by local authorities for all types United States and Canada. As a result, Japan of messages. The transmitters are located in the developed one of the more extensive systems in local government office and receivers are found in the Pacific. hospitals, schools, fire stations, emergency man- The Japanese Meteorological Agency (JMA) is agement offices and other places. Many residents responsible for issuing tsunami warnings. There have purchased receivers for their homes; the is one main observatory (in Tokyo) and five receivers are activated when a message, such as a regional observatories, all capable of issuing a tsunami bulletin, is being transmitted. Receiver warning. Data is continuously collected using towers or posts with loudspeakers are also satellites and cellular communication techniques installed on streets and roof tops of prominent to avoid failures associated with landline and government and commercial buildings. SAWS Internet technologies. The goal is to broadcast a effectiveness is reduced (as much as 15-20 % in tsunami warning less than five minutes from the urban areas) during inclement weather, when initial sensing of the earthquake. people close their windows. There is also an attachment to the telephone that can serve as a If an earthquake occurs offshore, the observato- dedicated radio receiver. A triggering signal from ries close to the epicenter will issue tsunami bul- the broadcast source will turn on the loudspeaker letins to their areas of responsibility. The bulletins and the SAWS message can be heard. SAWS is will go to the prefectures (similar to U.S. states) known as tone alert radio in the United States. through the Local Automatic Data Editing and Switching System (L-ADESS). L-ADESS will also Mobile Announcer System send forecast results (tsunami heights) to the This system is designed for those areas without main observatory and other observatories. The SAWS. Fire trucks mounted with loudspeakers main observatory will issue bulletins to other pre- cruise their area of responsibility to announce the fectures and alert other government agencies warning that they receive.

Special Paper 35: Tsunami Warning Systems and Procedures page 11 Television and radio conducted training to enable them to promptly respond to tsunami warnings. Tsunami warning announcements have priority Tsunami information is readily available in to cut into ongoing programs on government and the front of the telephone white pages. commercial television and radio stations. Stations Monthly siren and Emergency Alert System receive tsunami bulletins from the main and (EAS) radio and television broadcasts edu- regional observatories by C-ADESS or L-ADESS, cate the public in how to respond to emer- respectively. On television the message is either a gencies including coastal evacuations. subtitle on the bottom of the screen or a window. Later, the window has a map where the watch or 2. The PTWC monitors seismic activity warning applies. However, the map would not be throughout the Pacific, coastal tide gauges, shown fast enough in the case of a local tsunami. and warnings issued by other tsunami warn- In the case of the radio, an ongoing program is ing centers. interrupted with the message. This would have 3. Tsunami hazards of the Hawaiian Islands more impact than a message on a television have been mapped. This mapping identifies screen. areas according to their risk, based on his- Sirens and bells toric tsunamis approaching the islands from different directions. Sirens are found in some villages. The sirens prompt residents to turn on their radio or televi- 4. Data analysis techniques have been devel- sion for further information. Some villages stick oped that allow forecasts of major tsunami to traditional ways by clanging a bell to announce hazards for various locations. In a distant tsunami warnings. tsunami scenario, the goal is to evacuate Hawaii coastlines (200,000 to 300,000 resi- Telephone network and word of mouth dents and tourists) in a minimum of three Some communities have formed telephone net- hours prior to first wave arrival. In a large works to spread important information. In some local earthquake on the island of Hawaii, communities, the only way to reach people is by PTWC will issue an urgent local tsunami bul- going from house to house. Both methods are letin to at least two counties (Hawaii and time consuming, but are necessary to reach popu- Maui), based on historic tsunami risk lations that lack the other systems. records. Finally, local communities have extensive train- 5. The Hawaiian System is a coordinated effort ing, allowing them to respond automatically to between the Pacific Tsunami Warning Center tsunami warnings. Tsunami awareness is part of (PTWC), Hawaii State and County Civil coastal Japan’s culture — to the extent that upon Defense, and police departments. Uniform sounding a “high level” tsunami warning, the state and county tsunami emergency evacua- majority of the at-risk population, even if asleep, tion response plans are in place. These evac- have evacuated to safe ground within five min- uation plans are well understood, coordinat- utes. ed, and exercised between PTWC, the State, and County. When the PTWC issues a Hawaii System Tsunami Watch, State and County Civil The state of Hawaii is centrally located in the Defense issue an initial “Prepare to Evacuate” Pacific Ocean and is exposed to tsunamis generat- notice. When the PTWC issues a Tsunami ed throughout the Pacific Ocean. Hawaii is pri- Warning, Civil Defense plans to commence marily at risk from distant tsunamis rather than coastal evacuation. After discussion between local ones. There have been only two destructive these four groups, a decision is made to evac- local tsunamis (1868, 1975) recorded in 200 years uate. The county administrators and police of Hawaiian history. then activate sirens and the Emergency Alert System (EAS), as well as authorizing Civil The Hawaiian system includes the following ele- Air Patrol aircraft to fly over isolated coastal ments: areas announcing evacuation. 1. Tsunami awareness is part of coastal The siren sound is the National Standard Hawaiian culture. Local communities have alert signal (a three minute steady signal) page 12 Special Paper 35: Tsunami Warning Systems and Procedures that prompts people to turn on their radio, (NWWS) and a verbal notification, for state which carries the evacuation notice and warning points via the National Warning refers the public to the tsunami evacuation System (NAWAS). Local National Weather maps in the telephone book. They still main- Service offices immediately receive the text tain the old Emergency Broadcasting System warnings. (EBS), because there can be simultaneous 2. Response agencies receive and further dis- activation of the EBS with the sirens. The EBS seminate the warning also has the capability of sending out a longer message than EAS, which is limited to State emergency management agencies a maximum of two minutes. After PTWC receive the bulletin via NWWS and rebroad- issues a cancellation of warning, County cast over state owned teletype systems, e.g. Civil Defense will issue all clear announce- Law Enforcement Data System (LEDS) in ments over EAS. No sirens are sounded. The Oregon. They also receive a verbal notifica- EAS will be discussed in more detail in section directly from WC/ATWC via NAWAS. tion 4. Once the text bulletin is received, the state agency makes verbal notification to local 6. Hawaii has several models of sirens (327 jurisdictions via NAWAS, telephone, or other total) manufactured by Federal Signal communication systems Corporation. The model of siren is based on a professional analysis of the area to be 3. Local agencies receive the warning warned, because one model of siren may be Local jurisdictions on the coast receive a hard more effective in some locations than other copy of the warning via the state-owned tele- models. Most of their sirens are electronic, type system, typically within about 3-4 min- omnidirectional, and nonrotating. Some have utes from when the state receives the mes- voice capabilities. They have a few older sage. Local jurisdictions most often receive rotating mechanical and rotating electronic these bulletins at 911 centers where NAWAS sirens. They prefer nonrotating, electronic, equipment would be ideally located. and omnidirectional, because rotating sirens However, not all coastal 911 centers have do not send the signal out equally in all dedicated NAWAS drops, although there is directions and electronic sirens have voice usually one per coastal county. capability. They also have a few directional sirens placed in specific locations that only Very few local agencies receive warning bul- require one signal direction. Approximate letins independent of the state-owned tele- cost of one nonrotating, electronic and omni- type. However, NWWS and a similar wire- directional siren is $40,000-45,000. This less system known as EMWIN, are available includes design, installation, and voice capa- at moderate or very low cost. Both are satel- bility. Their mechanical sirens cost half as lite-based and require no landlines or tele- much. phone connections. Other systems 4. Warning goes to the general population The states of Oregon, Washington and California The general public can receive an audible contain various notification systems and proce- voiced warning directly from NOAA dures. The systems in coastal communities range Weather Radio and the Emergency Alert from advanced to none at all. Nevertheless, once System (EAS). Local NWS offices maintain a they receive the tsunami warning from the network of NOAA Weather Radio stations WC/ATWC, they issue a local evacuation notifi- that continuously broadcast weather fore- cation over whatever system they have. The fol- casts and special warnings along the West lowing usually takes place. Coast. In Oregon, approximately 70% of the at-risk population are within range of one of 1. Warning is created and disseminated these transmissions. The WC/ATWC issues a tsunami warning NOAA Weather Radio transmission of the through its standard notification protocol. Tsunami Warning will activate alarms on This includes distribution of a text bulletin specially designed receivers. Similarly, the through NOAA Weather Wire Service

Special Paper 35: Tsunami Warning Systems and Procedures page 13 EAS system receives the warning from and maintenance of a complementary public NOAA Weather Radio and can automatically education program. rebroadcast the message over commercial 5. Local action is directed by designated author- radio, television, and cable TV systems. All ities radio and television stations and cable systems with at least 10,000 subscribers are Communities may choose to evacuate on required by the FCC to have EAS equipment receipt of a tsunami warning. However, this installed and functional. Commercial broad- would likely be problematic and lead to a cast of state and local warnings, including perception of over-warning. In nearly all tsunami warnings, is voluntary. However, if communities, at least some part of the the local EAS plan specifies that a particular warned area will not be affected. Local offi- message type requires activation of EAS, cials can use the EAS system, sirens, tele- broadcasters must either carry the message phone calls, or other means to give explicit or go off the air. A community relying on evacuation directions, or other pertinent EAS must be vigilant about encouraging instructions, following the warning. broadcaster participation, periodic testing,

page 14 Special Paper 35: Tsunami Warning Systems and Procedures Section 4. Types of Tsunami notification system should be triggered quickly as Evacuation Notification an additional reminder that evacuation is neces- Systems and Procedures sary. The system is also useful for the all clear notification. Introduction However, there are four types of earthquakes that Local notification systems and procedures have create problems as far as using only “strong shak- two purposes. In the case of a distant tsunami, ing” as the trigger for evacuation: slow earth- they take a warning from the Pacific and West quakes, smaller subduction zone earthquakes, Coast/Alaska Tsunami Warning Centers and inland earthquakes, and earthquake-induced sub- issue the evacuation notification along the coast. marine landslides. They also respond to local tsunamis triggered by 1. Slow subduction zone earthquakes could locally felt earthquakes. A local community notifi- produce a devastating tsunami but not shake cation system incorporates personal observa- the coastal region much. A good example is tion/notification, community and agency train- the 1992 M7.2 Nicaragua earthquake. ing, sirens, radio/TV broadcasts, etc. However, a tsunami warning will be issued The effectiveness of any local community warn- by the warning centers within 15 minutes of ing system depends on the reliability of the inter- the earthquake origin time. In the case of the face between the community and the source(s) of Nicaragua earthquake and tsunami, it took information, training, and the accuracy of the about 45 minutes for the damaging waves to source information. A poorly defined interface reach shore. So the warning center messages results in a poor system. A well-defined system should be timely for an event like this. can result in a response that is protective, pre- Nevertheless, detecting these types of earth- dictable, and reliable. quakes and determining their tsunami potential will be a challenge. In all cases, training, including regular public information, is of singular importance. Special 2. An earthquake along one short segment of a information must be provided to transients, such subduction zone would be smaller in magni- as tourists and seasonal workers, who are less tude and shorter in duration than an earth- likely to know how to react to tsunami warnings. quake from a longer segment or the complete subduction zone. It might not be felt as To fully address evacuation notification systems strongly in adjacent regions, but the tsunami and procedures, there are two questions that need would still arrive relatively all along the to be answered. coastline. Time of arrival in adjacent areas 1. Is the tsunami local or distant? would vary from minutes to 1-2 hours depending on distance to the segment. There 2. Should the notification to coastal communi- would be loss of life if evacuation were based ties and the decision to evacuate from low only on strong ground shaking. Once again a lying areas come from centralized or decen- warning from the centers will go out within tralized locations? 15 minutes of the earthquake origin time and Local vs. distant thus arrive in those areas, 1-2 hours away, in a meaningful time frame for evacuation. If the tsunami were local, the notification to evacuate would come from the strong shaking of the 3. Local ground shaking does not necessarily ground or rapid draw down or sudden rise of the indicate that a tsunami is approaching. The ocean. The evacuation must be immediate. Local earthquake focus could be onshore miles notification systems, normally designed for dis- from the coastline, but still be felt. Examples tant tsunamis, would probably not be functional are the 1993 Scotts Mills earthquake in and should not be relied upon. If communities Oregon and the 1999 Satsop earthquake in would like functional notification systems that Washington. The Satsop earthquake trig- survive the ground shaking, then it would be nec- gered evacuation by 50-100 people. essary to strengthen the system hardware (towers, The local notification systems would proba- power lines, generators, etc.) and provide unin- bly function and the halting of evacuation teruptable power sources. If operational, the local could be accomplished quickly. These earth-

Special Paper 35: Tsunami Warning Systems and Procedures page 15 quakes would require advanced rapid earth- Distant tsunamis arrive hours after they are pro- quake detection systems that would notify duced. Local notification systems and procedures coastal areas immediately that evacuation is should be operational and can be activated. Most not necessary or halt evacuation in progress. of the discussion that follows will be on distant Public notification would then go out via the tsunami notification systems and procedures. The established system. The RACE system in local tsunami issue will be incorporated where Oregon and Washington and CUBE and pertinent. REDI in California are systems that automati- Centralized versus decentralized evacuation notifi- cally provide a preliminary earthquake loca- cation tion and magnitude. They could be important in the decision to stop evacuation A warning from the Tsunami Warning Centers already in progress. Subsequent bulletins usually reaches the coast from many sources, from the West Coast/Alaska Warning Center including NAWAS (National Warning System), would also indicate that evacuation should the Internet, EAS, news media, and NOAA be halted. However, there is no notification Weather Radio. Therefore it will be difficult to system that will set off an alarm immediately develop a sole information source for the tsunami following a felt earthquake that would notify warning. As long as the message is consistent, coastal communities that evacuation is not multiple warning sources should not be a prob- necessary. Existing systems can halt evacua- lem. tions in progress once they are officially noti- However, the decision to evacuate is another fied of no tsunami threat. issue. In the case of a distant tsunami, the deci- 4. Local onshore or offshore earthquakes could sion to evacuate all low-lying areas could be cause a submarine landslide that could gen- made from a central location, such as the state erate a very localized tsunami. The tsunami emergency management agency office and the would arrive in minutes. A rapid earthquake coastal notification systems could be triggered detection system would need to take this into from there. The decision could be made in coordi- account. Off southern California, several sub- nation with coastal jurisdictions. Another option marine landslide blocks have been identified. is for the decision to be made centrally, in coordi- There is concern there that local onshore nation with local jurisdictions, but trigger the earthquakes could induce submarine land- notification system (sirens, etc.) locally. Hawaii is slides and tsunamis. Local tsunamis in south- an example of this system. Finally, the decision to ern California have occurred in the past. A evacuate could rest on local centers or individuals submarine landslide triggered by a M5.2 who would activate the local notification system earthquake near Santa Monica Bay in 1930 through pre-planned procedures once they generated a tsunami with up to 6 meters receive the warning from the Tsunami Warning (19.5 feet) of run-up in the bay. This is not Centers. In reality, local jurisdictions in the five just a California problem. Earthquake- Pacific coastal states, except Hawaii, are solely induced landslides, no matter the earthquake responsible for making the decision to evacuate. source, could conceivably occur off the coasts Local decision-making would result in more local of Oregon, Washington, Alaska, and Hawaii. control. However, some jurisdictions or individu- Defining “strong shaking” and minutes of shak- als might be unwilling or slow to make the deci- ing for coastal residents and tourists could also be sion, and trigger alarms where appropriate, to a challenge. These descriptors are highly subjec- evacuate after they receive the tsunami warning. tive. One possibility is to use “shaking” as the Decision-making could be slowed for several rea- trigger for evacuation to account for these types sons. The public would be unnecessarily alarmed, of tsunamis and err on the side of caution. If all especially if inaccurately warned about an event clear notifications are rapid enough, the disrup- that is infrequent but of high consequence. The tion caused by false alarms should be reduced. official making the notification or society in gen- Another possibility is to leave the descriptor up to eral could be harmed socially, economically, and local government, so areas with more background politically. Delayed, muddled, or suppressed warn- seismicity could choose a higher threshold than ings from official sources would give importance those with a lower background. to unofficial sources, creating credibility problems. page 16 Special Paper 35: Tsunami Warning Systems and Procedures Going it alone in each community might result in centrally. They can also be triggered automatical- conflicting instructions and behaviors in adjacent ly. For example, the warning from the Tsunami communities. However, with a distant event, Warning Center or the state (who receives the there is enough time to make a regional decision warning via NAWAS) could be dropped into a by locals in a cooperative and coordinated way community intelligent receiver that is linked with input from state and federal agencies. This directly to the alarm. There are three principal should involve discussion among locals to devel- parts of a siren system: the siren, controller, and op regional plans for this coordinated effort. actuator. The siren produces the noise, the controller controls the siren as to signal type, dura- Central decision making would remove the deci- tion, etc., and the actuator triggers the controller sion-making burden from locals. However, the either remotely or directly. federal government and the states are not willing to take on that responsibility. Connecting the cen- Siren units, whether electro-mechanical or elec- tral decision center with local notification systems tronic, are essentially of two basic types: Those would also be expensive. Finally, central decision- designed to project sound at once in a 360 degree makers might not have as good a grasp on local pattern (omnidirectional), or those designed to and variable evacuation issues as would local offi- project sound in one direction while the unit cials. Nevertheless, wherever the decision lies, the rotates or oscillates through 360 degrees. Sirens notification to evacuate must be simple, clear, and can also be fixed. as consistent as possible. Sound source Configuration Installation Available notification systems and procedures Electronic Fixed Pole mounted Various types of systems and procedures for noti- Mechanical Rotating Mobile fying coastal residents and visitors of tsunamis are available and discussed in detail below. Directional Notification systems include sirens, telephones, Omnidirectional NOAA weather radios, the Emergency Alert System, and others. The goal for any community is to have the most effective coverage for the low- Units rotating through 360 degrees require a com- est cost. Therefore, it is critical to have local needs mutator ring and brush system providing an elec- professionally evaluated. The costs of implement- trical circuit from the mounting base to the siren ing new systems can be relatively high. They motor (or, in the case of electronic siren, to the include not only systems costs, but costs for other loudspeaker assembly). Units oscillating back and component systems (such as radios for activa- forth 360 degrees eliminate commutator ring and tion), labor, maintenance, and training. However, brush maintenance problems by using flexible new systems are more reliable than older ones. electric cabling between the mounting base and The high costs associated with purchasing new siren motor or loudspeaker assembly. Directional systems could be offset by higher maintenance sirens have a speaker or speaker array pointing in costs of older systems. In addition, if several adja- one direction. cent communities decide to use the same system, The benefit of a directional siren is coverage only costs could be reduced by purchasing equipment in those areas that are needed. The main differ- in quantity. ence between fixed and rotating is the amount of Sirens coverage area. A rotating siren increases the coverage area. For example the coverage area for a General considerations fixed siren would be a 1,000-2,500’ feet radius Sirens are devices that transmit different sounds from the siren; a rotating siren would increase the or voice messages depending on the action that is coverage to a one mile radius. For a stationary lis- required. They are either electro-mechanical or tener, the sound from a rotating siren goes up and electronic. These two types, along with siren down in loudness, while sending out the sound placement, sound projection, and alternate power wave in all directions. supplies, will be discussed in more detail in An electronic siren warning system can be aug- Appendix 1. Sirens can be triggered locally or mented by public address announcements.

Special Paper 35: Tsunami Warning Systems and Procedures page 17 Announcements can be on pre-recorded disks or intervals three times) to announce the all clear. In chips containing short instructive announcements addition, a few communities transmit voice mes- sent through the same speakers as the siren. sages in addition to or in lieu of tones. Sirens are also used to signal people to turn on their radios Controllers that control electronic sirens produce or televisions for an emergency announcement. up to seven signals For example, fire stations in Clatsop County, Wail Pulsed wail Alternate wail Oregon use three blasts with each blast lasting one minute. Sirens used in this way are all-pur- Steady Pulsed steady Alternate steady pose rather than tsunami specific. This adds a Westminster chime layer of complexity in developing a consistent siren system for tsunamis. Is it better to have an The coverage area for an electronic siren can be alarm, which prompts people to turn on radios or increased by adding more amplification. televisions, or should there be a specific tsunami Electronic models are often omnidirectional and warning signal? It would probably be more effec- fixed and are more expensive than electro- tive and simpler to have an all hazards siren that mechanical. Some electronic models are direction- prompts people to turn on the radio or television. al and rotating and can provide 360 degree cover- Radio and television messages, which provide age. more information, would probably be clearer than Ultimately, the siren system a community adopts a siren sound. will depend on the amount of funds available, Inland warning systems and procedures, and and the type and area of coverage a community potential new standards, must also be part of needs and wants. This will eventually require an developing a coastal warning system to ensure on-site analysis that only specialists can provide. consistency and reduce confusion. For example, The signal or voice message from the siren should the Portland Region Risk Management Planning be clear, concise, and distinct. There should be Group and the Oregon Local Emergency one tone for evacuation that sounds a distinct Management Council are recommending national period of time. The alarm or message should be adoption of a siren signal, developed in Denmark, uniform over as broad an area as possible. One that alerts the public to peacetime emergencies. advantage of sirens is they can reach all popula- The planning group was formed as a result of the tions, including those in isolated but populated Federal Clean Air Act 112r, which required a pub- areas (e.g. beaches). It can also reach populations lic meeting for chemical release warning systems. that have no or limited access to other warning The signal, which is different from a regular siren devices, such as NOAA Weather Radios, tele- signal, would mean to all persons in the United phones, and commercial television and radio, or States, “Turn on radio or TV. Listen for essential do not have them activated. emergency information.” Although there is already a national signal that prompts people to Siren Coverage in the Pacific Coastal States turn on their radio, the recommended signal The Hawaiian system, covered in detail in an ear- would be an improvement. The distinct tone lier section, is a well-established and tested sys- wavers, enabling people of different hearing abili- tem. In the other states the systems are local and ties to hear it. There is also a distinct and different quite variable, ranging from very good to nonex- all clear tone. istent. The systems vary with respect to type, age, Costs of selected siren systems and condition. The costs of sirens of selected systems for specific Even if several communities have siren systems, communities are outlined below. Costs range there can be significant differences. For example, between $10,000 and $40,000, with electro- the length of time the siren sounds is quite vari- mechanical at the low end and electronic at the able. Depending on the community, sirens are high end. Manufacturers include Whelan sounded for 90 seconds, 3-5 minutes, 1 minute Engineering Company, Inc., Federal Signal on/off, and 10-30 minutes straight if applicable. Corporation: Federal Warning Systems, and One community sounds the siren continuously American Signal Corporation (Appendix I con- for 3-5 minutes to announce a tsunami and con- tains addresses and telephone numbers). tinually for one minute (cycled at one minute page 18 Special Paper 35: Tsunami Warning Systems and Procedures Electro-mechanical sirens Kenai Peninsula, Alaska are outlined below. The specifics and costs of a directional, rotating Cannon Beach, Oregon purchased and installed a electro-mechanical siren from Federal Signal Whelan electronic system that includes a public Corporation: Federal Warning Systems address component. The sirens operate from a (FSC:FWS) for the small coastal town of simple storage battery power supply. The system Winchester Bay, Oregon are outlined below. The is run with solar powered batteries totally inde- costs are based on an estimate given to the com- pendent of the commercial system. The costs of munity in November, 1999. FSC-FWS has several the system are based on present costs rather than models with different coverage capabilities. The costs at time of purchase. 2001 model, used in this example, has a signal 1) $27,000 for equipment per station and $6,300 strength of 127 dBC at 100 feet, three distinct for technically qualified labor installing and warning signals (steady, wail, and fast wail), and testing equipment (total is $33,300 per sta- a weather resistant coating. The siren can be radio tion). The system without a public address activated which can minimize installation costs by component would cost $13,000 less. There eliminating the need for leased dedicated control are four units in Cannon Beach and two in lines. The siren will supply a minimum of 15 min- Arch Cape to the south utes of full power output from its batteries after AC power loss. Siren controls are available with 2) $2,000 for central triggering equipment (mag- battery operation (2001 SRN model), AC opera- neto-optical mini disc for pre-recorded tion, and AC operation with battery backup. One DTMF (Double Tone Multiple Frequency) unit covers a radius of approximately one mile and announcements) plus encoder (with suit- with a 60 degree projection. To cover just the able transmitter on hand). greater Winchester Bay area they would need one 3) $4,000 for site survey prior to installation of siren unit at $7,800, siren control at $3,100, radio units control at $1,500 and four back up batteries at $75 each. The total unit costs for one site would be 4) $5,000 per year for maintenance $12,700. This does not include the mounting pole Kenai Peninsula Borough has 28 Whelan omnidi- or installation costs. If FSC:FWS does the work rectional, fixed electronic sirens located through- they estimate it would cost about $5,000 for each out the borough. The system has been very reli- siren installation. able, with only two failures in 15 years. They esti- Used sirens have also been purchased by several mate the cost of one siren, including installation, communities in Oregon and Washington. to be approximately $15,000. The age of their Portland General Electric (PGE) recently sold 102 sirens varies and they plan to upgrade the sys- and 107 decibel electro-mechanical (various fixed tem. One upgrade would be to install a two way and rotating models) and Whelan rotating elec- communication component, that allows for silent tronic sirens from the closed Trojan Nuclear testing and testing for each function. They use the Power Plant. They sold for $1,000 each. The cost National Standard alert signal (wavering sound) included the siren, electric controls, mounting for tsunami warning and evacuation and a person brackets, radio receiver box, and technical manu- to person verbal message for all clear, because al. Rockaway Beach, Oregon, one of the pur- they have a small population. They also use a chasers, estimated that the purchase/installation three minute continuous national alert signal that and operation/maintenance costs per site were prompts people to turn on their radio. However, approximately $5,000 and $200, respectively. The often people can not distinguish the waver from 102 decibel sirens are single phase (regular outlet the continuous siren due to high winds. connection) and have an effective range (102-70 Therefore, Kenai Peninsula educates the public to decibels) of 1750 feet and an extended range (70-0 evacuate from low-lying areas no matter what decibels) of another 1000 feet. The 107 decibel siren signal is transmitted. They also recommend sirens are three phase (require special electrical the use of only two very distinct tones to reduce outlet connection, have an effective range of 3000 the risk of confusing one tone with another. Their feet and an extended range of another 1300 feet. sirens have voice message capabilities, but they Electronic sirens are not used, because the voice message from the speaker is often garbled, probably due to inade- Systems installed in Cannon Beach, Oregon and

Special Paper 35: Tsunami Warning Systems and Procedures page 19 quate speakers. In well-constructed houses, peo- hazardous material release, taking into account ple often cannot hear sirens, even though they are the properties of the material, prevailing winds, in the hearing radius of the siren. Therefore Kenai etc.). In the initial phase of CENS, the first area Peninsula uses other systems to ensure the public planned for implementation is a Tsunami is warned. They also use a sole source for sirens Warning/Evacuation Zone for the City of to insure consistency in product and service. Florence and surrounding coastal areas of Lane County. A digital representation of the Telephones warning/evacuation zone is required. Telephone notification systems are designed to CENS is a county wide public/private partner- automatically ring in the operational area (homes ship and is 50% funded by private industry. Lane and businesses) and notify recipients of the need Council of Governments (LCOG) is the plan- to evacuate. The pre-recorded telephone message ning/coordination/partnership-funding adminis- would announce evacuation in a clear and concise trator. LCOG contracts with Qwest for the service manner. The trigger would be from the emergen- and SCC Communication Corp. provides the ser- cy operation center (either local or central). vice. CENS can send out 2,000 messages of 30 sec- Cordova and Kenai Peninsula Borough, Alaska, ond length per minute under ideal conditions; and Lane County, Oregon have installed or are in however 500/minute on average is what is the process of installing these systems and their expected. It has no limit on the number of tele- efforts will be summarized. phones connected to the system. It can provide The auto dial system (Viking Model DVA-1000 is call-out lists and can set up preplanned event no longer available) has been in place in Cordova areas (for example, tsunami evacuation zones). It since 1984. The local telephone company pur- can stagger calls if needed, contacting the areas chased, installed, and maintains the system. The that will be affected first. It has an auto call back system is tested at least once a year and the list is feature, and deaf and other language capabilities. updated monthly. The telephone company The approximate costs for all of Lane County, absorbs the annual maintenance cost into its bud- population 300,000, are: get. The 1984 cost to purchase and install the hardware was approximately $15,000-20,000. 1. $24, 000 for one time set up The Kenai Peninsula Borough contracted with the 2. $45,000/year for operating costs based on Community Alert Network Inc. (CAN), a private 100,000 telephone lines ($0.02/line) company, for high-speed telephone notification of 3. Activation of the system during an emergen- citizens for tsunami evacuation. It costs them cy is $0.20/completed call. $11,000/year. CAN is considered a supplemental warning system to complement sirens, mobile A test of the telephone warning system was con- public address systems, door to door contact, and ducted in Florence (population 6,800) using a the Emergency Alert System (EAS). However, not tsunami evacuation message. It resulted in: all answering machines are designed to pick up 1. 500 telephones rung in 7 minutes, the recorded message, although the system is designed to call back two more times. CAN 2. 364 answers and 126 busy signals, no recalls up to three times if the phone is busy or if answers or messages left, there is no answer. Contra Costa County in 3. No tie up of the phone system, and California has also used CAN, specifically for petrochemical plant emergencies. 4. 42 out of 43 positive feedback responses. Lane County, Oregon is proceeding with the With a prerecorded message, telephones can development of a Community Emergency reach large audiences quickly. The system can be Notification System (CENS). CENS will give pub- used for multiple hazards. There are, however, lic safety officials the ability to send an outgoing limitations. You must be near a telephone. Phone telephone message to every phone number within lines might not be functional if damaged by an a specified warning area or evacuation zone. The earthquake. The lines could become overloaded if warning/evacuation area can be pre-determined, people call to confirm what they heard about a dis- or (at full implementation) can even be deter- tant tsunami or to confirm that the shaking felt is mined ‘on the fly’ (for example, in the event of a from a tsunami-producing earthquake. At present, page 20 Special Paper 35: Tsunami Warning Systems and Procedures cellular phones are not connected to the system. It encoding is a digital burst of data which describes calls direct dial numbers only (both listed and a geographic area by county; the nature of the unlisted). In certain cases where a building has a hazard by warning type; as well as the date, time, switchboard (e.g. motels and businesses or gov- and identification of the originating agency. ernment agencies with extensions), only the NOAA weather radio is considered a primary switchboard would be called and not individual notification system for the general public and a rooms or offices (unless the facility has a direct secondary system for emergency managers. inward dialing system). When people move they Receivers can be operated by battery or AC can retain their old phone number and if they are power. A household receiver typically costs $20- away from the coast they would still be notified $80 depending on features and sophistication. of a tsunami threat. This would cost money if the Commercial quality receivers add reliability and call is completed and it might be considered an functionality with costs rising commensurately. inconvenience to the recipient of the call. For a list of manufacturers of NOAA Weather A telephone system would be effective for distant Radios, visit the National Weather Service web tsunamis, because there are hours between the site (www.nws.noaa.gov/nwr). earthquake and when the tsunami reaches the The radios issue a warning only and not a call to distant shore. With a local tsunami, the system evacuate. The message from the NWS would might not be robust enough to withstand a large include, “take appropriate action or contact local earthquake. If the community relied solely on authorities.” This will be effective if the public is waiting for the telephone calls to evacuate, pre- properly educated. However, state and local cious minutes would be lost. Nevertheless, a seis- emergency management can send other informa- mically strengthened telephone notification sys- tion, such as a call to evacuate, out over NOAA tem, if in place, should be activated. It would radio to areas in need of evacuation information. reinforce evacuation that should begin once earth- The state can either request that NWS send out an quake shaking stops. If local tsunami arrival times evacuation notice or set up a system (requiring are more than 20-30 minutes, such a system might extra equipment) that allows a state or local juris- well have enough time to operate. diction to send an audio EAS message to NWS. NOAA Weather Radios The message would either be automatically sent to the targeted areas or reviewed by NWS and National Weather Service broadcasts all its warn- then transmitted to the targeted areas. The State ings, including tsunami warnings, on its existing of Washington has this automatic system in place. VHF-FM network, known as NOAA Weather It is functionally much easier and faster for locals Radio. Upon broadcast, these warnings activate to initiate EAS activation directly via an EAS alarms on specially designed receivers. Encoder than utilizing NWS for local messages. Confirmation of who has received the message is This would work for distant tsunamis. For local not part of the system. The general public will tsunamis, the system should be activated quickly likely seek confirmation of the warning from local to reinforce the evacuation notification provided authorities. The entire network was recently by the earthquake shaking. upgraded to interface with the new Emergency Alert System (EAS), which will be discussed in Weather radio can also be used with a call back more detail in a later section. NOAA Weather option by individuals who have received the Radio and EAS now work in tandem. A warning warning message and want to verify the warnings broadcast on NOAA Weather Radio can be auto- content. Either the broadcast itself, or the supple- matically rebroadcast on commercial radio, televi- mental information the broadcast refers to, can sion, and cable. Local authorities could use the contain a phone number that a person can call to EAS system to provide urgent follow-up informa- confirm that a warning is true. However, this can tion to the local public, such as an evacuation easily overload the telephone system. order, after the tsunami warning is broadcast. NOAA Weather Radio receivers are highly EAS and NOAA Weather Radio use a digital portable and a tourist population could be encoding scheme known as Specific Area encouraged to carry them when away from home. Message Encoding (SAME). SAME allows a warn- But educating and encouraging a transient popu- ing to be broadcast over a large area while acti- lation to use NOAA Weather Radio would be a vating alarms on only certain receivers. SAME

Special Paper 35: Tsunami Warning Systems and Procedures page 21 formidable challenge. A simpler solution would quate reception. This is hard to accomplish along be to encourage operators of hotels, restaurants, the rugged Oregon Coast. However, the network conference centers, campgrounds, and the like to can be expanded and improved. A new transmit- have a receiver on site in an area where a respon- ter typically costs $15,000 to 20,000. sible authority can monitor it (e.g., the front desk, In Washington, the state is providing $19,000 for camp host, and so on). A significant challenge equipment and installation of a new weather remains getting receivers into the hands of the radio transmitter. The NWS provides engineering, public. licensing, and other operating costs. In Oregon, However, there are some limitations to using the Tillamook County set up a joint commission to radio as a tsunami notification system. Tourist fund an upgrade of the county owned Tillamook populations would not be served unless the lodg- NOAA Weather Radio station. The project ing facilities (hotel, motels, campgrounds), restau- extended the coverage area by relocating the rants or stores have radios. Owners and managers transmitter and increasing output power, and of these facilities are then relied upon to spread improved reliability by providing backup power. the information to their immediate area, which has been previously designated in a tsunami Emergency Alert System (EAS) warning plan. In addition, tourists who visit iso- In 1996, the EAS replaced the outdated lated beaches or other low-lying areas would not Emergency Broadcast System. EAS is now the normally have a radio and would not be served. nation’s primary method for notifying the general Not all local residents and businesses would have public of emergency for all hazards. EAS stations radios, because either they do not want to own include all radio, television, and large cable oper- one or it is not a high priority, especially for low- ators. Messages can originate from any designat- income households. Some models have to be on ed authority: from the nation’s president, to the all the time and this may not be acceptable. Other state governor, down to the local incident com- more expensive models can be on standby and mander. For example: come on when a tsunami warning is issued. Bulk purchases would reduce costs. If funds were 1. NOAA/NWS receives the WC/ATWC tsuna- available to purchase the radios and distribute mi warning, rewords the message for media them to all households and businesses free of purposes, and retransmits it over EAS. charge, they would be very effective. An alterna- 2. The state receives the warning over NAWAS tive would be to provide rechargeable NOAA and transmits the tsunami warning message Weather Radios for rent in parks and camp- over EAS. Oregon, for example, sends out grounds along the same line as avalanche the tsunami warning to coastal county 911 transponders are available for mountain climbers centers via a dedicated telephone line. and Emergency Position Indicating Radio Beacons are available for boaters. 3. Local emergency managers can obtain and use their own radio equipment to broadcast Washington Emergency Management Division messages into the EAS network. In essence has a program encouraging the purchase of they can simultaneously commandeer all NOAA Weather Radios for coastal communities. broadcast facilities within a given area. This In partnership with the National Weather Service level of functionality comes with a price, they promote the purchase of radios. At times this however. Local broadcasters must voluntari- has included offers of discounts through specific ly agree to pass locally generated messages. vendors. They have also partnered with the The system is not automatic by any measure Washington State Grange to provide a weather and its usefulness depends on a community’s radio receiver to each school district and are willingness to make the system work. The expanding that program to include hospitals. local broadcasters and emergency managers On the transmission side of the equation, there must work together to develop and exercise are also challenges. Not all areas are within range a local EAS plan. However, once the EAS of a transmitter. For example, parts of Lane, plan is in place the broadcasters must carry Douglas, Coos, and Curry counties lack sufficient messages specified in the plan. signal strength to reliably activate alarms. The Manufacturers of EAS equipment include, existing transmitters require a line of site for ade- but are not limited to, TFT (www.tftinc.com) page 22 Special Paper 35: Tsunami Warning Systems and Procedures and Harris Corporation (www.broadcast.har- the listener when there is an alert. Receivers are ris.com/customer-service/sage). also available that meet the requirements of the Americans with Disabilities Act (ADA) by sound- 4. The EAS system can allow tsunami warnings ing an alarm or switching on a light. to jump directly from the NOAA Weather Radio network onto the EAS network. Critical problems with EAS are the existing and potential non-participation by broadcasters and However, it may be advisable to send the warn- the need for continuous education and testing. At ing message out over EAS from only one source, present, the system should not be considered preferably NOAA, to avoid media and public fully reliable. Many local jurisdictions have no confusion. NWS has 13 offices that receive and functioning plans and are not actively pursuing transmit EAS messages from the Tsunami them. If functional, this system should not be Warning Centers. used as the sole notification system for local Radio and television stations receive and retrans- tsunamis. It would, however, quickly reinforce mit the message. Radio transmits voice message the idea that people should immediately evacuate as is. Television may transmit as is or take the to high ground after an earthquake. voice message and write it up and present it as a bottom scroll message. Media may pick up the Emergency Managers Weather tsunami warning from the TWC independently Information Network (EMWIN) and transmit the warning anyway. It is important The EMWIN system was developed by the to work with media to insure the proper dissemi- National Weather Service especially for the emer- nation of the warning. gency management community. It is an increas- A key advantage to the EAS system is the flexibil- ingly reliable and easy way to receive official ity it allows local authorities to develop their own NWS warnings and forecasts. It delivers official emergency messages. EAS can be used to provide critical warnings, watches and advisories, as well multiple announcements, including evacuation as a vast array of routine weather forecast infor- notices, once a tsunami warning has been broad- mation, for any area in and around the United cast. Messages can be prerecorded and stored for States. The data is free. The costs are simply for immediate use. the initial hardware and software used to receive and display the information. There are other The coverage is wide: everyone has a television methods available, at higher cost to the end-user, and/or radio at home, business, and in their vehi- including various commercial weather distribu- cle. However, not everyone would be listening to tion systems. Visit the EMWIN web site for a list the radio or watching television. Current technol- of commercial vendors at ogy requires that the radio or television be turned iwin.nws.noaa.gov/emwin/index. on to receive the EAS bulletin. Future receivers will automatically turn on and display or play an Data can be received over the Internet or via EAS bulletin when it is received. Those people direct satellite downlink. The satellite broadcast is who are watching television via satellite dishes placed on two geo-stationary satellites owned and will not receive the EAS message. In addition, operated by NOAA. The signal footprint is the many coastal radio and television stations are not entire Western Hemisphere. Full information on staffed 24 hours. Even if staffed, the audience the system is available online at weather.gov. The would probably be minimal between midnight signal received from satellite can be rebroadcast and 6 a.m. The message is not a call to evacuate, locally via radio. This adds a point of failure, but because the information passed on from the is useful where a large number of users would Tsunami Warning Center is only a warning and not be able to afford $1,000-$1,500 for the one- not a decision message. time purchase of a satellite receiver. Cable networks offer unique challenges to imple- EMWIN users typically have a personal computer menting an EAS system. Small systems are not to ingest, display, and print weather warnings. able to insert an EAS bulletin on all channels Software can be obtained that will activate pagers because of the hardware expense. One option is upon receipt of a user-selected warning or even for the cable company to provide dedicated EAS forecasts. A typical use might be for an receivers that monitor a given channel and notify Emergency Operation Center (EOC) to have an

Special Paper 35: Tsunami Warning Systems and Procedures page 23 EMWIN in place that will sound an audible alarm AlaskAlert and print the text of any WC/ATWC bulletins Alaska does not have an accurate, timely geo- received. These bulletins would likely beat the graphically-based, all hazards alert and warning, Law Enforcement Data System (LEDS) and per- or civil notification system. With the exception of haps NAWAS notification by a minute or two. EAS, the systems in place in Alaska are old, limit- EMWIN is considered a secondary notification ed in coverage, unreliable, and difficult to use. system for emergency managers and the general They also frequently warn an area much larger public. For example, the Internet is convenient than that affected by a hazard, resulting in citizen but may be difficult or impossible to access in an complacency. NAWAS is present in only 20 com- emergency due to server overloads. Therefore, the munities. From these NAWAS points, additional Internet should not be used as the sole source of locations are warned using telephone or radio information for tsunami warnings and evacuation fan-out procedures. EAS is only marginally effec- notifications. However, all possible efforts are tive in Alaska because of inherent design deficien- made to ensure 24/7 availability. cies caused by lack of local broadcasting infras- Grays Harbor County in Washington reported an tructure, which is available in the lower 48 states. EMWIN success story during the Nisqually earth- Local notification systems, such as sirens, can be quake in Washington on Feb 28, 2001. The earth- effective in Alaska but their deployment is limited quake was centered northeast of Olympia and to only a few locations. NAWAS, EAS, or other was felt on the Washington coast. Grays Harbor notification systems do not provide accurate reli- County received the information from their able warnings to the citizens of Alaska. EMWIN System immediately after the earth- AlaskAlert is a notification system that is being quake. They received preliminary data in the first developed by the State of Alaska, but is adaptable few minutes (1857 UTC) from the ATWC. When to all states and territories. AlaskAlert is based on the emergency manager, Karen Frinell-Hanrahan, the MITRE Corporation’s MITREcasttm system. arrived in the Emergency Operations Center there The MITRE Corporation is an independent, not- was a Tsunami Information Message waiting on for-profit systems engineering firm engaged in the printer. It gave the preliminary magnitude scientific and technical activities in the public and location of the earthquake. interest. Over the past several years MITRE has When the emergency manager reviewed the developed a technique to provide geographically- information from the ATWC, she immediately specific messages using wireless technologies. briefed the Sheriff’s Office and called the local MITRE is working with FEMA to identify poten- radio station. The statement issued included the tial applications and is assisting in the develop- magnitude and location from the ATWC bulletin ment of a possible use in Alaska. The MITRE and stated that a tsunami had not been generated Corporation web site is and the residents could return to their homes, www.mitre.org/tech_transfer. schools, and businesses. Unfortunately, she was AlaskAlert will provide timely, precisely defined not in the office at the time of the earthquake and and geographically specific alerts and warnings to it took approximately ten to fifteen minutes to all citizens. It consists of encoding and transmit- broadcast the information. She would like ting equipment located at state and local govern- EMWIN to do a simultaneous broadcast page ment locations. It uses existing and future com- directly form the machine to the Sheriff and offi- munications infrastructure for transmission of cials in the coastal communities in Grays Harbor alerts and warnings. Transmission systems County, so that they get the information even include landline, microwave, satellite, fiber-optic when she is not in the office. cable, television, FM radio sub-carrier, etc. NOTE: At the end of 1999, they purchased an Stationary units will have a basic receiver and UPS 30 minutes backup power system for their will have a Global Positioning System (GPS) system to allow it to continue to receive data until receiver or will be programmed with the location their generator engaged in the Emergency of the unit. Receivers (chips) can be imbedded in Operations Center. They were able to receive data a multitude of devices including smoke detectors; the entire time. television, cable and radio receivers; hand held, portable, automotive or marine radios; or stand page 24 Special Paper 35: Tsunami Warning Systems and Procedures alone audio or video devices (for the hearing nificance of other alert systems. Supplemental impaired). Mobile units, automotive, marine or light signals (strobes or flashers) can be used to hand-held radios will contain a simple GPS. draw attention to them to clarify the meaning of a When one of these devices receives an alert signal primary public alert system when it has been acti- it will turn itself on and broadcast an audio or vated. video alert signal or message. The receivers do Aircraft: Aircraft could announce the evacuation not have to be in use at the time of the event. notification for distant tsunamis from a loud- Larger stationary systems located in towns or vil- speaker. This system would most likely be coordi- lages could have the ability to return an alert- nated by local fire, police and emergency manage- received message back to the initiator, confirming ment offices in coordination with Civil Air Patrol that a community had received the alert. or Air National Guard units. The contact would The cost of a system would vary depending on be personal and perhaps more believable. Aircraft area of coverage and number of receivers. The can cover isolated areas effectively. cheapest method would be to use a FM radio sub- Voice delivery requires a significant public carrier with receivers imbedded in dedicated FM address system that is not typically installed in or NOAA weather radios. The costs would be Coast Guard or Civil Air Patrol aircraft. It is $1500 for the sub-carrier plus the costs of the ded- important to use pre-scripted messages. Text icated radios. The costs of the radios would delivery requires designing, preparing, and stag- depend on the number of radios needed, which ing leaflets in advance. Once dropped, all of the would in turn depend on the area of coverage. leaflets would need to be recovered or quickly GPS capabilities would cost extra. Buying in large (less than a week) decomposed to prevent false quantities would reduce the costs. alarms or pollution. Towed banners or message boards are a possible option. (Towed banners for Miscellaneous systems fixed wing; message boards for helicopters.) Other possible public notification systems include Fixed wing aircraft have significant range and are aerial flares, explosive reports, billboards, aircraft, relatively quiet; however, flying low and slow to mobile loudspeakers, alpha-numeric pagers, e- deliver a message places the aircraft in significant mail, and amateur radio. risk. Helicopters are able to fly low and slow; Aerial flares or explosive reports: Aerial flares however, they are very noisy and have limited and explosive bangs (blank ammunition) would range. Aircraft could be called on to fly at any be useful for beach goers or others who are time and in any weather conditions. However, remotely located and, often by desire, not near flying in foul weather or at night requires special- conventional information sources. They could be ized aircraft and training. used to supplement other notification systems in Having the appropriate resources available on the case of a distant tsunami. They could be used short notice requires significant prior planning. to notify people to evacuate in the case of a local Coast Guard aircraft are available on a 24/7 basis, tsunami only if there is action within seconds but are primarily needed for search and rescue. after earthquake shaking stops. The liabilities of National Guard and CAP aircraft are rarely avail- aerial flares or explosive reports are: able on short notice. The use of the National 1. They would likely attract people to the Guard requires the prior approval of the source rather than encourage them to leave. Governor. 2. They are considered distress signals and can Mobile loudspeakers: Public address vehicles are generate false alarms that must be investigat- a viable option for areas where installing fixed ed by the Coast Guard while they are dealing public address systems is not cost effective. The with the tsunami alert. system can be designed to quickly bolt onto an existing vehicle and amplify a pre-recorded or 3. Pyrotechnics are dangerous to store and use transmitted message. This system could be practi- without proper training. cal for large beaches and parks. However, there Billboards: Strategically placed billboards are an would be limited staff covering a large area by excellent method to educate the public to the sig- vehicle.

Special Paper 35: Tsunami Warning Systems and Procedures page 25 Pagers: Supplying alpha/numeric pagers to peo- cesses involved with establishing siren or other ple in tsunami vulnerable areas would simplify hardware-intensive systems. technologies, increase coverage, and minimize E-mail: E-mail is useful when a text message is maintenance. The initial purchase price and sub- needed. E-mail can be used not only to activate scriber cost-of-ownership make pagers an over- pagers, but can transmit text messages to digital priced option for public notification. While it may cell phones. Digital messaging for cellular phones not be feasible in many places to do this on a does not operate if digital service shared with large scale, it may be practical for some small or your cell provider is unavailable. special settings. Pagers allow direct communication with responsible authorities (e.g., teachers), Amateur radio: Amateur radio operators can who then can direct actions to be taken. Pagers transmit messages along the coast for distant can be triggered by a broadcast calling service, events. They are especially important in situations through e-mail, or by a government-owned pag- where power is out. This notification system is ing system. Pagers can be discontinued if not limited, because correspondence would only be needed at far less cost than other systems and between individual operators and homes and they can be distributed quickly without the plan- businesses adjacent to the operator. ning, engineering, bidding, and contracting pro-

page 26 Special Paper 35: Tsunami Warning Systems and Procedures Conclusions messages. Ideally, there should be redundancies to ensure all people are notified and the decision Which system is best? to evacuate is positively reinforced. For example, There is no system that is best. The pros and cons a community may decide to use a telephone sys- of each notification system are summarized in tem and NOAA weather radios. The various Table 1. Notification systems should be tailored sources should not provide conflicting informa- for the community being evacuated. You need to tion. Conflicting information may decrease the know something about the people that you are credibility of the system and cause people to notifying to select the system that is best. When ignore the notification to evacuate. Therefore, you look at your audience, you need to find out planning and education are required to insure who they are, where they are, and what they efficient and timely evacuation. might be doing. All the issues below factor into How uniform should notification systems be? selecting the correct notification system for your Should the ultimate goal be to install the same audience. system everywhere? For the tourist or transient Audience? who travels between coastal cities, states, and countries, a consistent system might be important. Your audience can vary a great deal. Here are a Siren signals with different tones or duration few examples: could cause confusion as individuals travel. Elderly Children However, uniform systems could be difficult to Emergency responders Elected officials implement at a local and state level. Communities Tourists Locals have strong preferences, established and working Hospitals Factories systems, and limited funds. Schools Shopping centers Uniformity, if desired, would probably require a Parks Beaches large investment of money from the federal gov- Marinas/boaters Transient workers ernment. Perhaps communities and states that use similar systems could adopt similar signals and Activity? voice messages. For example, the standard siren What the person is doing can affect how quickly signal used by Hawaii (wail), and considered the they receive your warning. Here are a few exam- national standard, could be used by all communi- ples: ties to notify residents and tourists to turn on their radios in case of a distant tsunami. Or if a Driving Talking on the phone specific tsunami signal tone is preferred, then one Sleeping Playing of the other possible siren tones could be used Watching TV Listening to the radio exclusively for tsunami evacuation. Voice mes- Shopping Walking/running sages do not necessarily have to be the same mes- Working at a desk Working in a factory sage as long as the message is clear and distinct. Cooking Camping Nevertheless, uniformity would require planning Cost? and coordination between multiple jurisdictions. Cost is a major, possibly limiting, factor. Each The all clear should be distinct from the warning jurisdiction has different budgets and priorities. cancellation by the tsunami warning centers. The Although a community may decide on the best locals should have control over who returns to system for them, cost could be the main reason low-lying areas and when. The all clear should why that system is never installed. probably be considered part of the emergency public information function rather than the evacu- Size and Layout? ation notification system. EAS and other methods A large, spread-out community might require may be a more appropriate avenue for dissemi- multiple notification systems (for example, nating an all clear message than a distinct siren NOAA Weather Radios for the town center and tone designated for that purpose. sirens for the adjacent beaches). Finally, even if systems are different the evacua- Effective notification systems and procedures tion notification should be clear and distinct, require clear, concise, and consistent signals and whether it goes out over radio and television, (Continued on page 30)

Special Paper 35: Tsunami Warning Systems and Procedures page 27 Table 1. Pros and cons of the evacuation notification systems

Notification system Pros Cons Sirens Wide area of coverage Testing of actual siren could be public nuisance Coverage of isolated areas (beaches) High cost (includes purchase, installation, labor and maintenance) Audio component (electronic only) would Damaged by sand and salty air probably be more understandable than siren signal Widely recognized and has single focus Not-audible with high winds and to direct people to seek further information topographic barriers Can be activated through various channels High turnover in staff with manual trigger responsibility Control from central point for rapid noti- Connection difficult with a diverse group fication of sirens Maintenance is low if continually tested Siren meaning not recognized and ignored Confusion if adjacent communities have sirens with different tones and durations Nondedicated frequency can cause interference Telephone Wide area of coverage (all telephones with Must be near a phone and not using it direct dial) Cost effective for small areas and if used for Expensive for single use all hazards Audio component (more understandable Direct dial only (e.g. motel rooms and than siren signal) offices may not be connected) Reduces 911 calls Taxes phone system already stressed by local earthquake Pre-recorded message saves time Lack of human contact on telephone Can tailor message for special-needs Cell phones not covered population Presently has problems serving large populations NOAA Weather Easy to use Area of coverage limited to those with radios Radio Widespread and mobile Band width too narrow Inexpensive Must have on at all times (unless model has hazard specific call up feature) Audio component (more understandable than Warning message can be picked up by siren signal) media and individuals and announced prior to consultation with responsible official Message is rapidly transmitted, consistent, and Not all coastal areas are covered capable of being tailored Compatible across systems High rate of false alarms (people do not use them) Hand-crank and solar models available Potential encroachment by commercial industry Tied to Tsunami Warning Centers Alarm is triggered without cause and radio is turned off Mechanism for personal responsibility Reduces 911 calls (Continued on next page) page 28 Special Paper 35: Tsunami Warning Systems and Procedures Notification system Pros Cons Emergency Alert Established system with wide coverage Radio and television must be on System (EAS) Can be used to broadcast evacuation notice Not all radio and television stations are staffed 24 hours (old EAS) New EAS is totally automatic so staff is Does not work on satellite TV or small not needed cable networks Reduces 911 calls Power dependent. Some radio stations might not have back up power. Inexpensive Some areas have no coverage Message is consistent and rapidly sent (message Voluntary system and not always used can be modified by locals) (unless local EAS plan is in place) EMWIN Inexpensive Not a stand alone system (secondary system) No reliance on land lines (satellite based) Dish vulnerable to wind, rain, and snow (can lose signal) Continuous broadcast Can be teletyped into NAWAS AlaskAlert Accurate, timely, precisely defined, and Transient populations might not have the geographically specific proper receivers with them or in their vehicles. Receivers (e.g. televisions and radios) do not have to be on at the time of the event Relatively inexpensive, but depends on the coverage and number of receivers needed Ground shaking Known and intuitively simple Tsunami producing earthquakes not consistent with respect to shaking intensity and duration Warns hearing impaired Non-tsunami-producing earthquakes have potential for false alarms. This is a big issue in California and Alaska where there are many earthquakes of this type. The above are educational problems Miscellaneous— Reaches remote areas (aircraft, amateur radio), Limited in number and coverage. Slow Aircraft, amateur reach accessible areas not covered by other response by aircraft radio, mobile loud means (mobile loud speakers), complements speakers other systems Flares, explosives Complements other systems Dangerous to store and use. Considered distress signal and may be misinterpreted Billboards Simple, available 24/7, multicultural, Vandalism complements other systems Pagers Inexpensive if used for specific audiences, Coverage limited complements other systems Tone alert radio Useful for caregivers of dependent populations (SAWS) and for low population areas with adequate radio reception coverage Travel Advisory Tourists notified Need microwave upgrade, need to be on, Radio not everyone has one E-mails Rapid dissemination of information, text Coverage limited—access dependent message, complement other systems

Special Paper 35: Tsunami Warning Systems and Procedures page 29 (Continued from page 27) telephone, a public address system, NOAA no matter how expensive or sophisticated. weather radio, or the Emergency Alert System. Whatever system is chosen, all groups that are An effective evacuation notification system part of the notification process (emergency man- requires continuous public education. A system agers, media, etc.) should be involved in the plan- can never be totally effective without education, ning and implementation of their systems.

References May 1960 - Research on the Hawaiian disaster explores the consequences of an ambigu- Bernard, E.N., R.R. Behn, G.T. Hebenstreit, F.I. ous warning system, Science, v.133, p. 1405- Gonzalez, P. Krump, J.F. Lander, E. Lorca, 1409. P.M. McManamon, and H.B. Milburn, 1988, On mitigating rapid onset natural disaster: Mofjeld, H. O., F.I. Gonzalez, E.N. Bernard, and Project Thrust, Eos, v. 69, p 649. J.C. Newman, 2000, Forecasting the Heights of Later Waves in Pacific-Wide Tsunamis, Furumoto, A.S., H. Tatehata, and C. Morioka, natural Hazards, v. 22, p. 71-89. Japanese Tsunami Warning System, 1999, Science of Tsunami Hazards, v. 17, no. 2, p. Outdoor Warning Systems Guide, 1980, Federal 85-105. Emergency Management Agency, FEMA CPG 1-17, Washington, D.C., 17 p. Lachman, R., M. Tatsuoka, and W.J. Bonk, 1961, Human Behavior during the Tsunami of

Acronyms Environmental Laboratory (PMEL). PMEL is installing the systems (buoys and bottom sensors- CENS (Community Emergency figure 9) in the open ocean off Alaska, Oregon, Notification System) and Washington. The system uses sensitive A system that gives public safety officials the abil- water-depth detection equipment, underwater ity to send an outgoing telephone message to modems, satellite telemetry, and advanced signal every phone number within a specified warning processing to detect and measure tsunami waves area or evacuation zone. in the open ocean. Its purpose is to confirm that a potentially destructive tsunami has indeed been CREST (Consolidated Reporting of produced. Earthquakes and Tsunamis) EAS (Emergency Alert System) A project funded through the National Tsunami Hazard Program to upgrade regional seismic net- The EAS, which replaced the emergency broad- works in Alaska, Washington, Oregon, California, cast system, is the primary method for state and and Hawaii and provide real-time seismic infor- local officials to notify the public of an emergen- mation from these networks to the tsunami warn- cy, using the broadcast industry system. ing centers. EMWIN (Emergency Managers Weather CUBE (Caltech USGS Broadcast of Information Network) Earthquakes) The Emergency Managers Weather Information This system, designed for southern California, Network (EMWIN) is a satellite or Internet ser- provides preliminary earthquake epicenters and vice developed by the National Weather magnitudes (above a defined threshold) within Service and FEMA and operated by the minutes of the earthquake’s occurrence. National Weather Service and NOAA. EMWIN receives forecasts, warnings, and climate data DART (Deep Ocean Assessment and from NOAA Weather Wire and prioritizes it by Reporting of Tsunamis) message type. The system provides end users DART is a real time distant tsunami detector sys- with direct access to weather and warning tem developed by NOAA’s Pacific Marine information without reliance on landlines, mul- page 30 Special Paper 35: Tsunami Warning Systems and Procedures tiple layers of human intervention, or recurring NWS (National Weather Service) subscriber fees. The branch of NOAA which operates the tsunami GPS (Global Positioning System) warning centers and disseminates warnings. GPS is a technology that uses satellites to deter- PTWC (Pacific Tsunami Warning Center) mine the latitude and longitude of a position any- where in the world. Established in 1948 and located in Ewa Beach near Honolulu, the PTWC is responsible for issu- ITIC (International Tsunami Information ing warnings to Hawaii, to U.S. interests in the Center) Pacific other than the West Coast and Alaska, and ITIC was established in 1965 and monitors inter- to countries located throughout the Pacific. national activities of the Pacific Tsunami Warning RACE (Rapid Alert Cascadia Center and assists with many of the activities of Earthquake) ICG/ITSU, the International Coordination Group for the Tsunami Warning System in the Pacific. This system, designed for Oregon and Washington, provides preliminary earthquake LEDS (Law Enforcement Data System) epicenters and magnitudes (above a defined The use of LEDS is restricted to criminal justice threshold) within minutes of the earthquake’s purposes, except for emergency public safety occurrence. messages such as storm warnings, disaster warnings, etc. sent out by agencies responsible for REDI (Rapid Earthquake Data those areas. Integration) NAWAS (National Warning System) This system, designed for northern California, provides preliminary earthquake epicenters and NAWAS is a regional telephone hotline system magnitudes (above a defined threshold) within set up within each of the Federal Emergency minutes of the earthquake’s occurrence. Management Agency regions. The phone system enables any member of the NAWAS circuit to SAWS (Simultaneous Announcement immediately initiate a conference call with all the Wireless System) other members of the circuit. NAWAS provides SAWS is a dedicated system of transmitters and prompt communication when simple voice mes- receivers installed by local authorities for all types saging is adequate. NAWAS is considered a pri- of messages. mary notification system. THRUST (Tsunami Hazard Reduction NWR (NOAA Weather Radio) Using System Technology) The National Weather Service broadcasts all its Sponsored by the Office for U.S. Foreign Disaster warnings over NOAA weather radio, including Assistance/Agency for International tsunami warnings. Development, THRUST is a comprehensive pro- NWWS (NOAA Weather Wire Service) gram to mitigate tsunami hazards in developing countries. NWWS is a satellite or leased line subscriber service that distributes weather and warning data WC/ATWC (West Coast/Alaska Tsunami from the National Weather Service. NOAA Weather Warning Center) Wire is considered a primary notification system. Established in 1967 originally to issue warnings to NOAA (National Oceanic and Alaska of local tsunami events. WC/ATWC is Atmospheric Administration) now responsible for issuing warnings for any event likely to impact either Alaska, the West NOAA is a federal agency under the Department Coast of the US, or the Pacific coast of Canada. of Commerce responsible for tsunami warnings and monitoring.

Special Paper 35: Tsunami Warning Systems and Procedures page 31 Appendix I A vital consideration in planning a wide-area Siren Details siren system is the effective reach of the siren signal. The ambient noise level of the area to be blan- Sound Projection keted by the alarm signal must be part of that Projection of sound from either type of siren is consideration. Typical beach-side noise levels subject to natural law in which the sound energy from normal surf and normal wind is approxi- (sound pressure) projected diminishes ten decibels mately 70 decibels. The standard rule is for the at every doubling of distance between the source minimum level of the siren signal to be 10 deci- and point of measurement. This means siren out- bels above (louder than) ambient noise level; thus put measured at 120 decibels 100 feet out from the maximum effective range for a warning signal unit will diminish to 110 decibels at 200 feet, 100 should be considered no farther than the distance decibels at 300 feet, etc. Besides this fundamental from the sound generator to where it generally rule, various factors apply to selecting equipment delivers 80 decibels. Figure 12 illustrates effective for the intended area in order to hear the project- range under ideal conditions for each of three ed sound. These factors are shapes of terrain to be sirens having different decibel power as mea- covered by the sounding alarm, types and distribu- sured 100 ft away from the unit. The chart shows tion of significant foliage, sides and roofs of struc- significantly greater range of alarm coverage by tures within the area, prevailing wind patterns, what might appear as only moderate increases of prevailing air humidity and temperatures, and siren output power (decibels measured 100 ft frequencies of the sound being projected (lower straight out from the siren). frequencies traveling better than the higher). High powered sirens, such as 1 and 2 in the fig-

Distance (in feet) from Siren Unit

Figure 12. Range of effective warning sound by three sirens each with different output power against a general 70 decibel ambient noise. page 32 Special Paper 35: Tsunami Warning Systems and Procedures ure, when properly engineered and installed on tribution, can significantly influence sound 40-50 ft utility poles, project their sound horizon- reflectance or absorption. Seasonal changes of tally outward much like a jet of water from a hose deciduous foliage also can be critical in these nozzle. The main power moves straight out with regards. relatively little dispersion from 40-50 ft above Structure sizes, heights, outer wall surfaces, types ground level, essentially passing overhead above of roofs and their angles can all effect passage of nearby structures. As the projected energy’s main the projected alarm sound throughout the area stream disperses over distance, sound reaching and reduce its effectiveness. Consideration is ground level will be less forceful than when part needed concerning the effectiveness of the 80 of the energy’s main stream departs from the decibel range to awaken people sleeping at night siren. inside insulated homes. Another factor that needs High-powered sirens not specifically engineered to be considered and might be significant is the to project their principal sound outward in hori- prevailing seasonal wind patterns that can deflect zontal focus are less suited for installation where projected sound from reaching its targeted area. people move about at ground level in the open or Air temperature and humidity are also important occupy buildings close to the siren’s location. to consider. Projected sound tends to rise in warm High-powered sound will blanket the siren’s air. Failure to provide for that factor can shorten immediate area like a fire system sprinkler spray the system’s range of effectively delivering 80 saturating everything nearby with full pressure. decibel alarm sound. Finally, a siren’s metal parts can corrode in coastal areas and can be damaged Sirens rely on electricity and would therefore be by windblown sand in beachfront areas if not of limited use if the system is destroyed by a local designed specifically for those conditions. tsunami-generating earthquake. Backup systems A common problem in the proper selection of a or systems that do not rely on the AC grid, such site for wide-area outdoor siren units is to locate as solar, are possible as long as they survive the them next to pre-existing and convenient AC earthquake. Solar energy collectors would add power sources. Convenience is the determining costs to the siren system. However, costs of solar factor rather than whether such a location pro- panels have dropped significantly and allow vides maximum effectiveness for the siren. placement in areas where there are no power Another common siting problem arises due to lines, such as isolated beaches and parks. A solar- public objection to a technically ideal location. powered system, free from commercial connec- The type of siren unit selected is not engineered tion, would provide service if commercial power to have minimal impact upon its immediate loca- is disrupted by earthquakes and protect the sys- tion, although it has the high power required to tem from power surges. meet the extended area’s needs. An ideal site may Placement be also avoided because of public criticism about Besides the distance over which the warning the aesthetics or the belief that the proposed siren sound is to be heard, many important factors will negatively impact property values. must be considered in the placement of sirens. These obstructions in the selection of proper sit- Any of these other factors may in some circum- ing can lead to expensive alternatives, e.g. having stances become as important as the size of the to install more units than otherwise would have intended coverage area. been necessary or investing in inappropriately designed equipment. Such problems can perhaps For example, the character of the terrain around a be solved by well-planned public education as to siren station very clearly can deflect its projected the reality of the hazard and the need for siren energy away from an area expected (on basis of systems and incorporation of the public in the distance from the siren) to be covered. Shapes of planning process. Once this is accomplished, the terrain around the siren unit site can be so impor- location and thus resultant effectiveness of the tant that, for example, a siren station properly proposed notification system would likely be placed to take advantage of those terrain features more acceptable and considered a necessity to might ‘bounce’ or reflect the sound to an area minimize casualties in the community. otherwise having its line of site from the siren blocked by a hill. Types of ground surface, Although testing is important to keep residents including different kinds of foliage and their dis- and tourists aware and educated, the public may

Special Paper 35: Tsunami Warning Systems and Procedures page 33 also object to repeated testing. However, testing their sound in several ways to communicate dif- can be done without sounding the actual siren ferent meanings to the public educated to under- and thus reduce public complaints. stand them. For example, the familiar repetitive wailing sound, that usually signals an emergency, In summary, the selection of the appropriate is achieved by speeding up or slowing down the types of siren units and their effective placement siren’s spinning rotor to generate, respectively, is best realized when: high and low sound frequencies. 1. There is general public acceptance within the Length of time for the sound to change from low community that the hazard the siren system to high frequency or vice versa, is the “Sweep is designed to guard against is very real, and Rate” and is varied by turning power to the 2. A professional specialist, who is experienced motor on and off. The standard “Wail”, for exam- in acoustic surveys and types of siren equip- ple, is about nine seconds for the spinning rotor ment including their power supplies, trigger- to speed up from generating approximately 400 ing systems, and maintenance needs, is con- Hz to peaking at 1,000 Hz when power is cut off. sulted. Such a specialist will be equipped The rotor then slows to the lower frequency until with mobile siren units to test for maximum power is switched back on. The electro-mechani- effective warning sound coverage by types of cal siren’s signal can be varied. For example, the equipment best suited to various local fac- standard “Attack” siren tone, distinctive from tors. A system designed by this method will standard “Wail”, has a faster sweep rate (two sec- avoid costly errors made by inexpert siting onds) cycling between approximately 700 and and/or investment in siren equipment inap- 1,000 Hz. propriate to the local need. Sound patterns to communicate other meanings Electro-Mechanical Sirens to the public are available by other variations of sweep rate and/or length of time for the siren to Electro-mechanical siren units generate sound operate. For example, some community sirens are mechanically. That is, they are driven by an elec- turned on to run up to peak frequency and cycle tric motor and available in various types of back down once as a short activation (e.g. 15 sec- design and output power engineered for various onds) to signal “Noon Time”. uses. These range from small units on emergency vehicles to the large wide-area outdoor alarm sys- Electronic Sirens tem siren units requiring 3-phase AC power, from Electronic siren units are actually powerful loud- standard and available AC power sources (208, speaker systems broadcasting amplified electroni- 240, or 480 volts supplied by power company spe- cally generated standard tone patterns, e.g. cial transformers). Some electro-mechanical siren “Wail”, “Attack”, “Hi-Lo”, “Alert”, etc. Some ver- units incorporate storage batteries for limited sions of electronic siren units also offer the advan- operation if AC power fails – battery charging tage of broadcasting public address announce- having been maintained by AC power. During ments as well. This is a valuable feature, making prolonged power outages, when an AC-depen- it possible to communicate local emergency infor- dent siren’s use might be required more than mation quickly and efficiently to the public, espe- once, or if equipped with backup batteries for cially more transient populations. Versions pro- limited use, electro-mechanical siren units could viding a public address feature, depending on the be operated by a portable generator. If centrally specific model, can broadcast from microphone located, such as atop a fire station or city hall, for live-voice announcements, from pre-recorded auxiliary AC power is often available during gen- magnetic tape, or compact disk recordings. Some eral outages of AC service. versions are equipped to broadcast pre-recorded Control of siren operation can be by on-site man- messages stored in solid-state memory chips. ual switches or remote control over leased tele- Centralized or siren station controls can activate phone line or radio link to a central emergency any single particular station, groups of stations, or command center. Central or station controls can all the system’s stations for any of these functions. activate one unit, a group, or all units. Electronic siren units are available, competitively Sirens generating emergency signals especially for priced, in as many varieties of output power as a community warning system may need to vary the older technology electro-mechanical sirens. page 34 Special Paper 35: Tsunami Warning Systems and Procedures The costs of selected units are discussed later in Alternate Power Supplies this section. Some units operate from 120 volt AC Though briefly discussed above, the choice of power while others are engineered to operate power supply for siren notification systems is from low-voltage storage battery systems. In the vital when planning a system and thus requires event of AC power failure, some of those intend- special mention. As already described, various ed to rely upon such a power supply, have back- versions of both electro-mechanical and the more up storage batteries enabling operation for a lim- modern electronic sirens rely upon either AC ited time. power of 120 up to 440 volts or low-voltage stor- Some of the electronic sirens’ engineering design age batteries. provides significant advantage over electro- A community notification system engineered to mechanical sirens. One such advantage is the operate directly on AC service line power is con- high-power electronic siren’s ability to operate stantly at risk from power outages or electrical from a low voltage battery power supply. In a irregularities capable of damaging siren unit con- wide-area disaster, AC power outage may be pro- trols. This is particularly the case when lightening longed and emergency services officials will likely strikes within the community. Lightening can need more than brief use of the community notifi- decommission the entire siren unit regardless of cation system (e.g. repeated notifications, public protection devices. In addition, power lines con- address advisories about hazards, or other emer- nected to siren units broaden the exposure to gency type announcements). Electronic siren lightning strikes. In the northern Pacific, power units, engineered to operate regularly from their lines are also subject to adverse coastal atmos- low voltage storage battery systems, offer lengthi- pheric conditions during the frequently hostile er service than siren units intended to operate on winter season. Ongoing expenses for AC service AC but having a limited battery backup. should be factored in when making the decision However, when backup batteries are found about the type of power supply system. depleted, they can be replaced or a portable generator can supply AC power as needed. A disad- Siren units engineered to operate directly on low- vantage is electronic units often require more voltage storage battery power with the battery maintenance than electromechanical models in charge maintained by AC service have their siren coastal marine environment. controls and equipment far better protected. The batteries stand between the siren elements (except A community notification system, comprised of the battery charger) and the AC power line’s electronic siren units specifically engineered to potential for damage to elements of the station operate from low-voltage battery systems main- control system, e.g. relay coils and/or solid state tained by solar charging, will operate entirely electronic circuitry components. independent of AC power. Solar charging equipment has plummeted in price during the last Ideal protection for siren units and their controls decade, making this method of maintaining bat- is to have no connection at all with AC power teries practical against costs of installing AC lines, even for charging the battery power supply. power connections. Additionally, battery systems Instead, maintain the battery system by a solar- maintained by solar power make it practical to powered charger. As already mentioned, during install siren stations in strategic locations remote the last decade prices have fallen to make solar from AC power service. Powering an electronic equipment competitive with costs of equipping siren unit with a solar-maintained battery system alarm system stations with AC power. Wind sys- has other advantages. For example, the unit is tems are also cost effective. entirely protected against AC system voltage Battery power supply systems need to be engi- spikes, surges, and other irregularities, which neered properly. For example, where a siren unit sometimes cause significant maintenance prob- is driven directly by AC power but is equipped lems for the unit’s control systems and other elec- with backup batteries in case of AC loss, it is nec- trical elements. essary to recognize that the batteries’ life span Control of siren operation can be by on-site man- will be shortened if they are not regularly ‘exer- ual switches, remote control over leased tele- cised’. Proper maintenance will require systemati- phone line, or radio link to a central emergency cally using them for a full operational test of the command center. siren unit (power drawn by the test should paral-

Special Paper 35: Tsunami Warning Systems and Procedures page 35 lel what an emergency activation would require) batteries. Service life of even the highest quality to insure they can provide adequate backup 12-volt batteries in similar circumstances can be power when needed. Simply relying upon the fact extremely short due to their thin plates buckling that there are backup batteries in the siren unit from the heat developed while powering the without maintaining proper testing routine would siren. be imprudent. Careful consideration of these principles is even Critical to the success of a battery power supply is more important when planning systems to be the selection of proper batteries for their intended used both for broadcast of siren alarm tones and use. Use of sirens in one community, for example, public address announcements. The latter puts a may differ significantly from needs of another heavier load on the power supply than simple community: A community having a heavily pop- siren tone patterns. ulated tsunami inundation zone might anticipate In summary, where storage batteries will be used the need to use their alarm system several times either as backup for loss of AC power or for basic during an emergency. A coastal community with- operation directly, planners of a wide-area siren out extensive exposure to tsunami hazards might alarm system need to recognize the vital impor- foresee only the briefest use of sirens. The capaci- tance that properly engineered power supplies ty of battery power supply systems would signifi- are the solid foundation for the proposed system. cantly differ between those two communities. Equipment and power supplies for a system’s This is true for siren units engineered to operate needs should not be determined by trial and directly from battery power supplies as well as error, but with guidance by specialized profes- siren units operating directly from AC but having sionals having broad experience in wide-area backup storage batteries. alarm systems. Type of battery selected is very important. The following web sites have more information Experience shows that batteries for wide-area on sirens: alarm systems should be robust deep discharge, uninterrupted power supply (UPS), 6-volt batter- www.warningsirens.org ies rather than from half as many 12-volt batter- www.warningsirens.com ies, because of less wear and tear on battery plates. Such 6-volt batteries have far sturdier www.airraidsirens.com plates. While discharging to power the siren, the www.sirensystems.com load is also spread over significantly more plate surface than it would be in half as many 12-volt

page 36 Special Paper 35: Tsunami Warning Systems and Procedures Appendix II 2. Federal Signal Corporation: Federal Warning Siren Manufacturers Systems 2645 Federal Signal Drive University Park, IL 60466-3195 1. American Signal Corporation 800-548-7229 10245 Enterprise Drive 3. Whelen Engineering Company, Inc. Mequon, WI 53092 Route 145, Winthrop Road 800-243-2911 Chester, CT 06412-0684 800-63SIREN

Appendix III d. Easily integrated with audio component Tsunami Warning e. Single focus–direct people to seek fur- Workshop Summary ther information f. Widely recognized as warning and par- Over 80 people from Alaska, California, Hawaii, tial systems already in place Oregon, and Washington attended a day and a half tsunami warning workshop in Portland on g. Maintenance is low if continually tested May 14 and 15, 2001. They represented emergency 2. Cons management, communication, fire and police, a. High cost (equipment and maintenance) public works, and science. The workshop was especially for small communities funded by the National Tsunami Hazard Mitigation Program. The workshop began with b. Siren meaning is unknown (education presentations on the Tsunami Warning Centers and testing required) and six evacuation notification systems (sirens, c. Non audible with winds and topogra- NOAA weather radio, telephones, EMWIN, EAS, phy and AlaskAlert). The pros and cons of the differ- d. Old mechanical ones are in place or ent evacuation notification systems and system being installed (High maintenance- consistency and needs were discussed in two needs weather protection) breakout sessions. The breakout group discussions e. Single focus use of siren (not cost effec- were summarized in two main sessions. Several tive as a mobile siren) recommendations came out of the breakouts and presented during the main session. Consensus was f. Siren ignored reached on five of the recommendations. There g. Diversity of types with connection diffi- were thirteen other recommendations that need cult further discussion and, if possible, consensus. The h. Access to siren trigger is necessary and following is the workshop summary. responsible person needed. If manual trigger (what if person cannot get there). I. Pros and cons of the evacuation notifi- If high turnover in staff, possible lack of cation systems understanding of warning information A. Sirens i. Difference in local systems (tones and 1. Pros duration) is confusing a. Controlled from central trigger point j. Non-dedicated frequency can cause which has potential for rapid notifica- interference/garbling tion B. NOAA weather radio b. Can be activated through various channels 1. Pros c. Good for special conditions (beach, a. Wide-spread and mobile (cars, homes, other remote area where tourists, tran- business, boats etc.). Easy way to get sient populations are located and isolat- information to public. ed, and confined communities) b. Affordable

Special Paper 35: Tsunami Warning Systems and Procedures page 37 c. Hand cranks, battery operated, solar D. EAS models 1. Pros d. Can be on standby and turned on a. Redundancy specifically for tsunamis b. Widest coverage e. Message is rapidly transmitted c. Modifications can be made Message is consistent and can be tai- d. Can be made automatic with existing lored technologies f. Mechanism for personal responsibility e. System in place g. Adds redundancy f. Local input possible (e.g., message from h. Compatible across systems EOC) i. Tied into tsunami warning center g. Message consistent and rapid. Both j. Reduces 911 calls audio and visual message 2. Cons h. Inexpensive a. Coverage problems i. Relieves 911 b. Only works when on 2. Cons c. Need to know your location with a. Need to have receivers on respect to tsunami inundation zone b. Doesn’t work on satellite TV or small d. High rate of false alarms (people do not cable networks (<10,000 users) use them) c. Power dependent e. Band width too narrow d. No radio coverage in some areas f. Potential encroachment by commercial e. Radio stations might not have back up industry power g. Alarm kept going off so was not used f. Limited applicability-not focused C. Telephones enough, difficult to make changes 1. Pros g. Regulatory issue - voluntary system not a. Out of state/off site mandatory b. Redundancy h. Maybe passe in future if new technologies are brought in c. Good for distant tsunami i. In place but not always in use d. Less calls that 911 has to make E. Ground shaking e. Pre-recorded message saves time 1. Pros f. Tailored warnings for special needs a. Known and simple g. Goes to all with telephones b. Warns hearing impaired h. Cost effective for small areas (all hazards) 2. Cons 2. Cons a. Not consistent with respect to intensity a. Probably not operable during an earth- and duration of shaking that triggers quake evacuation (low shaking intensity could b. Taxes systems that are already stressed still produce a tsunami-slow earth- during earthquake quakes). How strong is strong, how long is long, when do I evacuate c. No human contact b. Educational problem d. Problems serving large populations (new technology could solve this prob- c. Not reliable indicator of tsunami (false lem) alarm issue) e. Does not go to cell phones d. In some states where there are more earthquakes (CA and AK), evacuation f. Not effective in short warning time sit- for any shaking would result in many uations false alarms page 38 Special Paper 35: Tsunami Warning Systems and Procedures F. EMWIN tem, i.e. standard, would make education easier. 1. Pros Tsunami Ready and CRS-tsunami programs, with their incentives, would ease the adoption of stan- a. Continuous broadcast dards. National standards are already in place for b. Teletyped into NAWAS sirens. A three minute wail tells people to turn on 2. Cons the radio or TV to seek emergency information. a. Dish is vulnerable to wind, rain, snow, Thus the siren would act as a multi-purpose and can lose signal warning system. However, existing sirens are inconsistent with respect to tone and duration. G. Others Can all existing sirens produce one tone and one 1. Helicopter leaflet drops expensive duration (steady or wavering, three minute wail) 2. Travel advisory radios need microwave if a standard is adopted? NWR can provide a con- upgrade, sightseers drawn by warning, only sistent message if more transmitters are built and activate when people turn them on. Not more people have them. A consistent educational everyone has them message must follow the establishment of any 3. OASIS (CA) Satellite phone system that links standard. counties to state with seismic networks, Consistency issues are also associated with evacu- expensive and limited band width, effective ation and warning cancellation (the all clear) and in extreme rural areas safe zones. Are there liability issues with safe 4. High Frequency/FM can simulcast large zones? What is a safe zone? Is it an official gather- areas, may not communicate shorter dis- ing place or just a safe place to be? Are shelter or tances, hard to get frequency allocation, link- supplies there? Zones imply land use in less system California. 5. Civil Air Patrol (CAP) Slow response, for dis- Is ground shaking a consistent notification? What tant tsunami warning only constitutes a tsunami producing shake: is it strong II. Consistency issues with evacuation shaking for several minutes? Is the public better notification trained for duration or intensity? If communities err toward safety, there could be false alarms, Regional consistency is possible only if there is especially in California where strong shaking central coordination at the national level. The earthquakes are common. The Papua New United States population is very mobile and Guinea earthquake was not strongly felt but pro- many people are unaware of hazards of regions duced a devastating tsunami (with loud noises they enter. and extreme water level changes). However, if consistency is reached and standards III. Evacuation notification needs are created would communities need to comply and thus take a risk in not complying? There A. Coordination/Standardization could also be issues with standards being consid- 1. National standards with flexibility for local ered an unfunded mandate. It is also difficult to jurisdictions standardize the system with differences in rural, 2. Focus and direction from the national level semi-rural and urban areas. Neighboring commu- 3. An organization that will set consistent nities differ in their response and it may become a guidelines/standards and recommendations political issue within states and even over state lines. Evacuation decision that are driven by spe- 4. Consensus from 5 state group on key issues cific policies within a community cannot be dis- 5. FEMA should include warning as mitigation counted. Standards should include a spectrum of 6. Realistic expectations of Coast Guard by choices for rural to urban areas. locals Standards are also important because the news 7. Governing agency for tsunami disasters media crosses borders. If standards are in place 8. Take into account political constraints and economies of scale kick in, i.e., there are shared state and regional differences resources and templates, a common core of 9. Acquire political backing at local, state, understanding (educational consistency), and a national levels universal interface. A regionally consistent sys-

Special Paper 35: Tsunami Warning Systems and Procedures page 39 10. Regional communication and coordination quakes. Education of people who speak dif- 11. Develop positive partnership with local ferent languages and have other special media (EAS) needs. Public education on what sirens mean. Continuous staff training at the state B. Financial and local level 1. Funds 3. Incorporation of tsunami inundation infor- 2. Take into account monetary constraints of mation into NFIP maps many communities when developing stan- 4. Education at the PSAP level which is the dards choke point for coastal dissemination of 3. Alternate funding sources and prioritization evacuation notification criteria for sirens in fund-strapped communi- 5. Public education about local earthquakes ties (both tsunami and non-tsunami producing) C. Technical E. Message 1. New technology for improved warning sys- 1. Consistent messages, including all clear tem 2. Guidelines on how to set up media messages 2. Consistency with sirens (tone and duration). 3. Reduce time for communication of 3. Guidelines on how to set up a siren system EQ/tsunami info 4. Reduction in false alarms from local non 4. Rapid dissemination of event size and loca- tsunami-producing earthquakes tion (especially important for non-tsunami 5. Frequent testing of systems earthquakes) through improved seismic 6. Expand NWR (more installation of transmit- monitoring ters and radio purchase) to target as many 5. Procedures for getting word out on people as possible Nisqually-type earthquake need to be clear, 7. 24/7 coverage at local, state and federal level e.g., when to trigger an alarm to improve delivery time of evacuation mes- 6. Information about non-tsunami producing sage earthquakes should be over NWR 8. Back up tsunami warning center (in WA, OR, 7. Consistency in definition of key terms for or CA) evacuation and evacuation notification 9. Develop technology to send generic codes 8. Resolve all clear problem (how to hold back from ATWC direct to EAS 1st responders (particularly volunteers)) 10. Use NWR to activate another system 9. Knowledge of the official source so locals can 11. Phone conference bridge that enables coun- make decisions accurately ties to speak at once so that state can get big 10. Streamline or improve tiered system of dis- picture tribution (ATWC-state-local-public) 12. Integrate packet radio with paging Internet 11. Follow up on evacuation message receipt 13. Local ordinances/codes to require installa- 12. Flexibility with respect to WC/ATWC can- tion of appropriate devices (e.g., NWR inter- cellation and local cancellation. Some com- face via smoke detector chip) munities will choose to maintain EOC activa- 14. Space based resources in conjunction with tion and evacuation other uses to measure movement of wave 13. State level all clear- however liability concern across Pacific Ocean F. Science 15. Complete and redundant systems 1. Knowledge of hazard areas and basic tsuna- D. Education mi science 1. Siren test for awareness raising 2. Improve uncertainties in tsunami research 2. Better communication and outreach educa- (inundation lines are not supported by hard tion to residents, tourists, and transient science) workers both land and water based about 3. State tsunami advisor to interpret scientific tsunamis and non-tsunami-producing earth- data page 40 Special Paper 35: Tsunami Warning Systems and Procedures G. Evacuation c. Develop scientific group to assess 1. Consistency in how evacuation maps are pre- tsunami hazard: sented: same scale, color etc. using GIS Group needs to coordinate with emer- 2. Standards for evacuation maps in phone gency management books Train scientists on tsunami science if 3. Do more good than harm, e.g. not evacuating needed people to URM areas, moving huge popula- d. If multi-state issue, FEMA responsible tions down narrow streets preferred by for bridge between states developers B. Other recommendations (to be discussed and IV. Recommendations consensus reached) A. Consensus reached 1. Web site for 5 states emergency managers to 1. Adopt standard educational brochure that develop guidelines contain 2. Patch communication holes to enable a. A glossary of terms NWR/EAS coverage b. See, hear, feel triggers for evacuation A. Original FEMA protocol See water rapidly withdraw 3. Trigger for warnings-evacuation, consistent activation for distant tsunamis Hear loud roaring sound 4. Embed NWR/EAS information into existing Feel earthquake shaking that makes it appliances (pagers, cell phones, etc.). As you difficult to stand enter area, notification is triggered c. Five state logos 5. Watch would mean prepare to evacuate, d. Standardized map tailored for each warning would mean consider evacuation state 6. All states have a tsunami advisor to interpret e. Sample Sign with running man scientific data 2. National recommendation for evacuation 7. PMEL provide scientists for expertise in notification: Running man with tsunami interpreting various data post event symbol 8. More research and analysis of landslide gen- 3. If sirens are used for evacuation notification, erated tsunamis the recommended national standard (three 9. Schools in inundation zones should plan and minute wail that prompts people to turn on practice evacuation drills radio or TV for further information) should be used regardless of siren type 10. WC/ATWC and PTWC should establish voice grade HF. This requires working with 4. All clear FCC and FEMA for frequency set up. This a. Standardized language would be good back up to wireline (which b. Establish criteria/procedures for when NWR is on), because wireline is not robust it will be issued (separate criteria for to ground shaking local and distant tsunamis) 11. Install multiple warning systems to insure c. Add definition to glossary in brochure complete coverage 5. State level conference call during distant 12. Have tsunami warning workshop at the tsunami event state level a. Establish conference call number 13. NAWAS adopt pre alert message that b. Include scientists on call allows time for state to bridge the counties

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