Cascadia Winter 2005

News and information from the Oregon Department of Geology & Mineral Industries

Volume 4, Number 1 www.OregonGeology.com Winter 2005

Where will it be tomorrow? In this issue: From your State Geologist – page 2 Our changing Oregon coast Please don’t take the cobbles – page 3 Tsunami hazard mitigation update – page 4 owhere is nature’s ability to shape the New coastal staff – page 5 Nlandscape more Measuring beach morphodynamics – page 6 apparent than on the ocean Shoreline change in littoral cells – page 8 shore. The ocean, aided by tides, rain, rivers, and cur- South Oregon coast mapping – page 10 rents, constantly and some- Know, know NANOOS – page 10 times dramatically chops away at the land. The result of this natural process af- fects those who have chosen Who owns the beach? to live within this dynamic Most people think Oregon’s beaches landscape. Our coastal are publicly owned. Th at’s not entirely communities are growing correct. Th e public does own the wet sand faster than ever before, but beach, up to the ordinary high tide line. the price for some is homes But the dry sand beach is usually part of abandoned and communi- the adjoining upland property. In many ties threatened by the same cases, this is privately owned. forces that drew people Even so, the public has a perpetual there. Our coast is also seis- easement to use the dry sand beach up mically active and subject to the statutory vegetation line or the line to infrequent but severe cat- of established upland shore vegetation, astrophic earthquakes and whichever is more inland. Th is easement tsunamis that have flood- is set out in the Oregon’s Beach Bill. Th e ed low-lying shores, bays, Beach Bill guarantees the public unre- and river valleys. Televi- stricted use of dry sand beaches, even sion images of landslides those that are privately owned. and tsunamis also remind Many state agencies share responsi- us how sudden and cata- bility for managing resources and uses in strophic these forces can be. Oregon’s coastline, which extends three Inside this issue of Cas- nautical miles (5.6 kilometers) from shore. cadia, you’ll learn how Many of these responsibilities are now scientists at the Oregon guided by the policies of the Territorial Department of Geology Sea Plan. Even so, the task of coordinating and Mineral Industries policies and agencies is complicated. are addressing the com- The dynamic nature of Oregon’s coastline is evident even As demand for coastal development plex and sometimes costly along the same stretch of beach. Here in the Neskowin increases, the geologic information the questions of understanding littoral cell, wave-caused erosion has stripped the beach Department of Geology and Mineral In- and dunes of sand, threatening homes, while new dunes dustries (DOGAMI) provides serves as coastal processes and the advance on other dwellings. You can learn more about lit- interaction between nature toral cells on page 8. (Photos: Jonathan Allan) a basis for prudent decision-making in and man. resource development and land manage- (continued on page 5) 1 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

making. Developing a means to distribute Notes from your information and data is as important as collecting and compiling it. Our coastal staff regularly meets with coastal govern- State Geologist ment and planners to explain coastal pro- by Vicki S. McConnell cesses. Th ey have organized several work- Oregon State Geologist shops to address tsunami evacuation and coastal processes. We now have a Coastal Processes and Hazards Working Group that meets to exchange information about n 1999 the 71st Legislative Assembly of benefi ts for forming partnerships with activities and identify problems that could Oregon acknowledged the increased coastal communities and organizations use a coordinated response eff ort. Ipressure on Oregon’s coastlines and responsible for the health and welfare In fi ve years we have forged strong authorized DOGAMI to open a Coastal of the coast. After considering several working relationships with many coastal Field Offi ce. Th e last time a fi eld offi ce excellent proposals for co-locating, we communities to assist with hazard miti- for DOGAMI’s Geologic and Services were delighted to accept the off er of the gation and education about coastal pro- Program had been opened was in 1937 Oregon Coastal Zone Management As- cesses and response, and we have built when the agency was formed! Th is action sociation (OCZMA) to co-locate in their a reputation as a “go-to” scientifi c team. by the legislature speaks volumes about Newport, Oregon offi ce. Th e offi ce is We are coordinators with federal, state, the interest and concern that Oregon has modest and not staff ed for visitor infor- and academic organizations to collect and for its coastlines, beaches, headlands, and mation, but you can learn more about distribute basic information about coastal littoral cells. In early 2000 we announced it and the staff by visiting our website: processes ranging from wave energy to at a DOGAMI Governing Board meeting www.OregonGeology.com. beach cobble migration (see page 6, Coast- the opening of the Coastal Field Offi ce in al Observatory story). Finally, we continue Newport, Oregon with our permanent to listen to what the coastal communities staff consisting of a Regional Geologist Ultimately, our mission tell us they need. Th is year we have includ- and a Coastal Geomorphologist. is to assist coastal ed a proposal in our mapping program to We had several goals in mind for the communities with land- initiate a geologic mapping project along new fi eld offi ce and its professional staff . the south coast in response to increases in Now after fi ve years we can evaluate our use decisions by helping population and development pressures on performance and review our strategic communities understand city and county governments. plan. We have increased our knowledge What do the next fi ve years hold? We of the processes that shape our coast and the processes and want to complete all the tsunami inun- about how coastal communities view hazards that shape our dation mapping for coastal communities their relationship with those processes. coastline. and begin to develop maps for the less Ultimately, our mission is to assist coastal populated areas that host large visitor communities with land-use decisions populations. Our work would include new by helping communities understand the We recognize that coastal communi- information acquired from study of the processes and hazards that shape our ties face a variety of hazards; some, such as Sumatra earthquake and tsunami of 2004. coastline. Coastal communities are not the tsunami hazard, are unique to coastal We want to expand our beach morpho- restricted to cities and counties but also areas. A primary scientifi c goal for the dynamic monitoring to include most of state and federal agencies that have re- Coastal Field Offi ce staff has been charac- the northern coast and incorporate sand sponsibilities to coastal residents and to terizing and mitigating for coastal hazards. budget data. We plan to incorporate our stewarding the Oregon coast. See page 5 Read up on some of our projects about tsu- dynamic revetment data into research for of this Cascadia for a list of some of the namis on page 4. We also recognize that developing improved shoreline protection most involved state agencies. the very processes that shape our coast- structures. We want to make all our data Our fi rst goal was to fi nd a location line are not well understood and we lack and maps available and interactive from for the fi eld offi ce that would be as acces- basic data to increase our understanding. our website. sible as possible to coastal communities. Feature stories throughout this Cascadia It gives me great pleasure to announce As the coastline of Oregon is about 360 publication explain some of our projects we have had a banner fi rst fi ve years for miles (580 km) long there is no simple to monitor and collect data that our part- the Coastal Field Offi ce and we plan to centralized location. We did, however, ners, policy makers, and scientists alike continue with enthusiasm, genuine inter- want to capitalize on a location with can use for scientifi c and policy decision- est, and strong science.

2 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

Cape Lookout shoreline stabilization study G E O L O G Y F A N O D T N M I E N M E T R

R A A L Please don’t take the cobbles P

I E

by Jonathan Allan U

R E

S ignificant erosion along the Oregon O coast during recent winters is the Sresult of an unprecedented number 1937 of major storms that generated excep- Cascadia is published by the Oregon tionally high waves, together with the un- Department of Geology usual impacts of the 1982-83 and 1997-98 and Mineral Industries 800 NE Oregon Street, #28, El Niños. The erosion has been especially Suite 965, Portland, OR 97232 severe at Cape Lookout State Park on the (971) 673-1555 FAX (971) 673-1562 northern Oregon coast. Cape Lookout State Park is located at Governing Board the south end of a “pocket beach” litto- William Elliott, Chair - Lake Oswego ral cell, centered about 1.25 miles (2 km) (image courtesy of Don Haagensen - Portland north of Cape Lookout and at the south Dr. Paul Komar, Vera E. Simonton - Pendleton Oregon State University) end of Netarts Spit. A significant cause Barbara Seymour - Oceanside Steve Macnab - Bend of erosion here was the northward shift of beach sand within the littoral cell as a result of the southwesterly approach of inland some 410 feet (125 m). State Geologist - Vicki S. McConnell waves during the El Niños, but most cata- With its protective dunes gone, the Assistant Director - Don Lewis Cascadia Editors - strophic were the series of extreme storms park could expect more damage during James Roddey, Deb Schueller during the winter of 1998-99. El Niño ero- subsequent winters unless some form of sion beginning in 1982 had eliminated the shore protection was constructed. line of high dunes that provided protec- The Oregon Parks and Recreation De- Mineral Land Regulation and Reclamation Program: tion to the park, so the 1998-1999 storms partment (OPRD) has the primary man- 229 Broadalbin Street, SE, Albany, OR 97321 were able to inundate the park facilities. agement control on deciding whether (541) 967-2039, FAX (541) 967-2075 Maximum wave penetration reached (continued on page 9) Gary W. Lynch, Assistant Director

Baker City Field Office: 1510 Campbell Street, Baker City, OR 97814 (541) 523-3133, FAX (541) 523-5992 Mark L. Ferns, Regional Geologist

Coastal Field Office: 313 SW 2nd Street, Suite D Newport, OR 97365 (541) 574-6642, FAX (541) 265-5241 Jonathan C. Allan, Coastal Team Leader

Grants Pass Field Office: 5375 Monument Drive Grants Pass, OR 97526 (541) 476-2496, FAX (541) 474-3158 Thomas J. Wiley, Regional Geologist

The Nature of the Northwest Information Center: Suite 177, 800 NE Oregon Street, #5 Portland, OR 97232-2162 (503) 872-2750, FAX (971) 673-1562 Donald J. Haines, Manager Internet: http://www.NatureNW.org

(left) Cape Lookout State Park and the locations of survey transects used to monitor the For a free copy of this and past dynamic revetment and artificial dune. (right) DOGAMI coastal geomorphologist Jonathan issues of Cascadia, visit Allan checks the artificial dune after a major storm event. Although waves overtopped the www.OregonGeology.com dune, the combination of cobbles and construction techniques proved that this method of or call (971) 673-1555 stabilization is a viable alternative to riprap. (Diagram and photo: Jonathan Allan) PRINTED ON RECYCLED PAPER

3 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

Are you ready? Tsunami hazard mitigation update wo tsunami events on opposite sides of the world have galvanized Oregon coastal communities during the Tpast year. First was the magnitude 9.3 subduction zone TSUNAMI earthquake off the coast of Sumatra on December 26, 2004 that created a massive tsunami that killed hundreds of thousands EVACUATION MAP of people around the Indian Ocean. The second event was the WALDPORT tsunami warning announced by the West Coast and Alaska 101 Tsunami Warning Center and broadcast by NOAA on June DEVILS BEND Sign Post Banding 14th, 2005. The events were very different, but to people on BAYVIEW A FIRE HALL Look for colored bands the Oregon coast they meant the same thing — “you better get ALSEA BAY near the tops of sign WALDPORT posts ready because you may have only minutes to save your life.” A YELLOW band indicates that you are DOGAMI has been involved with tsunami hazard mitiga- WALDPORT ALSEA within the tsunami HIGH 34 hazard zone. SCHOOL W A HW L D P tion on the Oregon coast since the legislature passed Senate Bill PACIFIC OCEAN Y O . A GREEN band indicates R T that you are outside the H

. E

CEDAR R H tsunami hazard zone. 379 in 1995, which directed the agency to map the coast and D IG DR. E H N T

NORWOOD DR. I SLOUG S L D ALSEA T R . create a “line” that indicates the worst case scenario runup for a S RE

RANGE DR. LINT YAQUINA JOHN tsunami following a subduction zone earthquake oﬀ the North- POINT DR. RIVER MERTEN DRIFT west coast. Bill 379 also limited construction of new hospitals, ALSEA Y. R. CREEK SI E D ECKMAN WAY D HWY. HW N 34 LSO LAKE schools, and other similar public-service buildings in tsunami NE

WALDPORT ST

fl ood zones and was the fi rst step in ongoing eff orts to prepare . ELEMENTARY A D MAP SYMBOLS R COA SCHOOL

K E

E EVACUATE FROM THIS coastal communities for the eventuality of a tsunami similar R MT.

C ECKMAN AREA N

GON M in size to the one that struck Sumatra, India, and other south K OUTSIDE HAZARD AREA

E ORE Asian countries. EVACUATION ROUTE Th anks in large part to the work done by Dr. George Priest A ASSEMBLY AREA

BEACH FIRE STATION of DOGAMI’s Newport Field Oﬃ ce, coastal residents are em- WAKONDA BEACH WALDPORT BRIDGE

AKONDA

W bracing tsunami preparedness. Maps and evacuation brochures POST OFFICE 101 SCHOOL created by Priest, public education, and evacuation planning–as T. 13 S. R.11-12 W. W.M. well as NOAA funded off shore detection systems–are part of an CITY HALL ongoing strategy to save lives and reduce losses from tsunamis. Waldport’s tsunami evacuation map clearly shows inundation areas, safe areas, and assembly areas. DOGAMI and Oregon Emergency Management Public http://www.oregongeology.com/sub/earthquakes/Coastal/tsubrochures/WaldportEvac.pdf Education specialists have traveled extensively along the coast, attending town halls and working with local communities to Learn about tsunami preparedness and review the June 14th demystify tsunamis. But the June 14th tsunami warning from After Action Report from OEM online at http://www. NOAA was a telling example of how much work still needs to be oregongeology.com/sub/news&events/ done before Oregon coastal communities are truly prepared. OEMTsunamiWarningReport6-14.pdf Seaside’s Tsunami Outreach Program wins 2005 Excellence Award TSUNAMI EVACUATION Th e City of Seaside’s Tsunami Awareness Outreach Program has been honored with a 2005 Award in Excellence in the Educational ROUTE Outreach to General Public category by the Western States Seismic Policy Council. Under the leadership of Outreach Coordinator Darci Connor, the city hosted neighborhood, business, and school workshops, held a poster contest, and conducted a tsunami drill. Crucial to the program's success were many vol- Darci Connor, Seaside Tsunami Outreach unteers — students, business leaders, and neighbors. Pre- and post-event surveys Coordinator, explains to Seaside middle showed that community members had a signifi cantly better grasp of tsunami facts school students how a tsunami can be and disaster preparedness after the program. To learn more about Seaside's program generated from an earthquake off- shore from the Oregon coast. and how your community can design a similar program, see Th e City of Seaside's (Photo courtesy of Kevin Cupples) Tsunami Awareness Program Outreach Assessment: How to implement an eff ec- tive tsunami preparedness outreach program, DOGAMI Open File Report O-05-10, available from Nature of the Northwest (http://www.NatureNW.org).

4 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

Who owns the beach? Major state agencies involved in your Oregon beaches: (continued from page 1) Oregon Department of State Lands (DSL) - ment. DOGAMI also provides informa- http://www.oregon.gov/DSL/ tion on coastal geologic hazards, water re- manages these lands on behalf of the State Land Board (the Governor, Secretary of State, and Treasurer) and has co-authority over rocky intertidal areas with the Oregon Parks and sources and marine minerals to the public. Recreation Department. DOGAMI is also responsible for issuing permits for oﬀ shore oil and gas drilling in Oregon Parks and Recreation Department (OPRD) - state waters and for regulating any such http://egov.oregon.gov/OPRD/ drilling or seabed mining operations. has authority over the “Ocean-shore Recreation Area” (that width of the ocean shore that is submerged by the daily tides) as well as the adjacent “dry sands beach” up to the “beach zone line” set in state law (approximately 16’ feet above high tide). OPRD has management New coastal staff — authority over rocky intertidal areas as well as upland state parks. Oregon Department of Environmental Quality (DEQ) - Introducing Rob Witter http://www.deq.state.or.us/ Dr. Robert C. Witter has joined the is responsible for water and air quality in Oregon’s ocean area. Oregon Department of Geology and Oregon Department of Fish and Wildlife (ODFW) - Mineral Industries coastal office as a http://www.dfw.state.or.us/ Regional Coastal Geologist. regulates marine fisheries, protects marine wildlife, and manages marine habitat in state “We are delighted to have Rob with ocean waters, including rocky shores. us,” said Dr. Jonathan Allan, DOGAMI Oregon Department of Land Conservation and Development (DLCD) - Coastal Office section leader. “He http://egov.oregon.gov/LCD/ brings a new dimension in paleoseis- is the primary agency for coordinating state ocean-resource management and planning mic research that will help extend our activities. knowledge of Cascadia subduction Oregon State Marine Board (OSMB) - zone earthquakes and tsunamis and http://www.boatoregon.com/ will greatly aid our hazard assessment regulates boating activity in state waters. program here on the coast.” Dr. Witter has 12 years of research Managing with Federal Agencies Oregon experience in the regional history of has developed and maintains a close working relationship with many federal agencies in order to manage ocean resources and uses. earthquakes and tsunamis along the Cascadia subduction zone. He has Oregon Department of Geology and Mineral Industries - participated in geologic and seismic http://www.OregonGeology.com hazards studies funded by the U.S. Additional state agencies involved in your beaches include: Geological Survey, the U.S. Depart- ment of Defense, utilities, and the pri- Oregon Water Resources Department (WRD) and the Water Resources Commission - vate sector. In addition to the Cascadia http://www.wrd.state.or.us/ subduction zone, Dr. Witter has stud- administer state laws regulating the use of surface water and groundwater. ied faults in California, Washington, Ports Division of the Economic Development Department - Alaska, the Central U.S., and Turkey. assists the state’s Port Districts in promoting economic development. Dr. Witter has also participated in Oregon Department of Forestry (ODF) - a National Science Foundation sup- http://oregon.gov/ODF/ ported study of a 7,000 year geologic manages three state-owned forests in the coastal zone totalling over 600,000 acres. record of tsunamis triggered by great Oregon Department of Health Services (DHS) - Cascadia earthquakes that struck the http://www.oregon.gov/DHS/ southern Oregon coast. monitors the water quality of public water systems to ensure protection of public “I am very happy to be back in health including the quality of oysters and other shellfish to assure that they are safe for Oregon and excited to continue my consumption. research on coastal and geologic haz- Oregon Department of Energy (ODOE) - ards,” said Dr. Witter. “I look forward http://www.oregon.gov/ENERGY/ to finding innovative ways to reduce provides staff support to the Energy Facility Siting Council (EFSC). EFSC administers the risk in Oregon’s coastal communities state’s authority for siting, monitoring and regulating the location, construction and posed by earthquakes, landslides and operation of major energy facilities. our changing climate.”

5 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

Assessing the temporal and spatial variability of coastal change on the northern Oregon coast Measuring beach morphodynamics— by Jonathan Allan

ur Oregon coast is an exceedingly dynamic Study Area: Rockaway Littoral Cell environment. The coast is exposed to one For the fi rst phase of the pilot beach shoreline study, DOGAMI is mapping the beach surface in Oof the most extreme ocean wave climates three subcells of the Rockaway littoral cell (see in the world—storm waves over 30 feet (9 m) high page 8 of this Cascadia for more on littoral cells): regularly pummel the shore. When combined with • the south-central part of Nehalem Spit high ocean water levels, these storm waves can • north of the Tillamook Jetties • the central part of BayOcean Spit cause extensive beach and dune erosion in a very The initial survey of these three regions was car- short time. Notable examples of erosion include ried out in November 2004. Port Orford on the southern Oregon coast, the towns of Neskowin and Rockaway, and along much of Netarts Spit in the north. To understand the impact of storm-induced ero- coupled with high ocean water levels, sion, DOGAMI Coastal Field Office staff, with which enable the wave swash to reach to partners from the Department of Land Conserva- much higher elevations at the shore. tion and Development Coastal Management Pro- Periodically, erosion processes may be gram (OCMP) and Oregon Parks and Recreation enhanced due to climate events such as Department (OPRD), are studying the temporal an El Niño. El Niños occur about every and spatial variability of Oregon’s beaches as part 2 to 7 years and increase the risk of beach of a pilot beach shoreline study. This study will help erosion due to both an increase in mean scientists, coastal managers, and the public under- wave heights and an increase in mean el- stand the impacts of storms on the coast by exam- evation of the sea. El Niños also infl uence ining several key questions: the predominant tracks of the storms as • What processes drive Oregon coastal changes? they cross the North Pacifi c ocean, so • How often do erosion events occur, and how that ocean waves tend to arrive at the quickly do beaches respond to large wave shore mainly from a southwesterly direc- events? tion. Th is last process can result in strong • How quickly do beaches recover from erosion northward directed (longshore) currents episodes? landward of the wave breaker zone, which • What is the best form of protection are capable of transporting large volumes for properties subject to erosion? of sand from the south ends of the litto- This project is part of a larger coop- ral cells northward along the shore, where erative venture to establish a Pilot the sand accumulates. Coastal Ocean Observatory for the Luckily, the erosion of Oregon’s Estuaries and Shores of Oregon and Beach Processes in Oregon beaches is not entirely one way (i.e., land- Washington under the umbrella of the Coastal processes contribute to sustained ward and to the north). Periods of beach Northwest Association of Networked periods of erosion that can cause the toes rebuilding during the summer and during Ocean Observing Systems of coastal dunes or high bluff s to retreat periods characterized by lower average (NANOOS: http://www.nanoos.org/). landward and threaten property and wave heights (e.g., the period 1988–1996), More detailed information on the infrastructure located too close to the and by a return of sediments to the south pilot project can be found at http://www.ccalmr.ogi.edu/nanoos/. beach. Erosion events are generally driven ends of the littoral cells balance landward by major storms that produce large waves and northward erosion.

6 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries Learn more about the Coastal Ocean Observatory at www.OregonGeology.com —Oregon’s Coastal Ocean Observatory

Measuring Change To understand how Oregon’s beaches respond to waves and currents over time, during low tides we survey cross-shore beach profi les with a Trimble 5700/5800 vehicle displays the survey lines. Using the Information Global Positioning System (GPS) mount- Transect lines are typically 50–65 feet After the data are processed, various prod- ed on a backpack. DOGAMI is currently (15–20 m) apart and extend some 2 miles ucts, such as beach profi les, are derived. surveying along the Rockaway cell and (3.5 km) along the Beach profi les show response of the beach Clatsop Plains and will soon begin in the shore. Because the to variations in off shore wave energy (e.g. Neskowin cell. Th ese surveys are typically GPS unit samples winter versus summer wave conditions) carried out on at least a quarterly basis every 1 second, and to major storms (i.e. how much dune and/or after major surface mapping or bluff retreat occurred), data that are storms. can generate a extremely useful when designating hazard Th e approach is data set consisting zones along the coast. to walk from the of 10,000–15,000 All information is available through landward edge of survey points within each study area in the OregonGeology website: the primary dune, just a few hours. http://www.oregongeology.com/sub/ navigating along a Nanoos1/objectives.htm predetermined line (Photos and diagram: Jonathan Allan; using a hand-held NANOOS logo: courtesy of Tom Guthrie) computer, over the dune crest, and down the beach face to wading depth. Th is method can reliably detect elevation changes greater than 2 inches (5 cm) — well below normal seasonal changes in beach elevation, which typically varies by 3–9 feet (1–3 m). To understand larger-scale changes in the shape and confi guration of the beach, which may be due to the development of rip embayments, hotspot erosion eff ects as a result of El Niños, or the movement of sand waves along the beach, mapping of much larger stretches of shore is required. To achieve this, a GPS unit is mounted on a 6-wheel amphibious ATV vehicle, and the vehicle is navigated along predetermined survey transect lines at speeds of 6–10 miles per hour (10–15 km per hour). Rockaway littoral cell #3 station (left) and beach profile (right) for surveys made 1997–2005. Th e region covered typically includes the The profile highlights the seasonal response typical of Oregon’s beaches, characterized low-tide line up to the toe of the dunes or by accretion during summer and erosion during winter, as well as the change caused by bluff s. A computer mounted inside the extreme storms between 1997 and 1998.

7 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries Shoreline change in littoral cells by Jonathan Allan he Oregon coast is about 360 miles (580 km) long is broadly characterized as long stretches of sandy beaches bounded Tby resistant headlands. These systems are referred to as littoral cells. There are at least 18 major littoral cells on the Oregon coast (see map below, right). Most of the shore (72%) consists of dune-backed sandy beaches; the rest is a mixture of bluff-backed beaches, rocky shores, and coarse-grained (gravel) beaches. Because headlands extend into deep water, wave processes are generally regarded as unable to transport beach sediment around the ends of the headlands. As a result, headlands form a natural barrier for sediment transport, preventing sand exchange between adjacent littoral cells (see Aerial view of the Beverly Beach littoral cell on the diagram below). Th us, a littoral cell is essentially a self-contained com- northern Oregon coast. (Photo: Jonathan Allan) partment, deriving all of its sediment from within that cell. Beaches composed of loose sediment are among the most dynamic 125˚W 124˚W 123˚W 122˚W and changeable of all landform types, responding to complex variables that reﬂ ect the interaction of the processes that drive coastal change WASHINGTON

(waves, currents, and tides) and the underlying geological and geomor- COLUMBIA RIVER 46˚N Seaside (a.k.a. Clatsop) phological characteristics of beaches (e.g., sediment grain size, shoreline Tillamook Head orientation, beach width, sand supply and losses). CANNON BEACH Cape Falcon

Depletion of beaches along the Oregon coast is largely de- ROCKAWAY pendent on high-magnitude events such as the March 2-3, 1999, Co Cape Meares lumbi ver NETARTS a Ri storm, or in response to enhanced periods of storm activity such Cape Lookout SAND LAKE as the 1982-83 and 1997-98 El Niños and 1998-99 winter. Collec- Cape Kiwanda OREGON NESKOWIN tively, these events resulted in some of the most signiﬁ cant ex- 45˚N Cascade Head amples of coastal retreat observed during the past three decades. LINCOLN Cape Foulweather For example, during the late 1990s dune erosion averaged about BEVERLY Yaquina Head 38 and 49 feet (11.5 and 15.6 m) along the Neskowin and Netarts Newport littoral cells, respectively, and as much as 180 feet (55 m) in some NEWPORT

(continued on page 10) Cape Perpetua HECETA Heceta Head 44˚N n a e c O EXPLANATION c COOS fi Littoral cell ci a coastal boundary P COOS Littoral cell name Coos Bay Cape Arago Coos Bay Geographic locale

BANDON 43˚N

Cape Blanco PORT ORFORD (a.k.a. Elks) Port Orford Heads HUMBUG Sisters Rocks NESIKA Hubbard Mound N GOLD BEACH (a.k.a. Rogue) Cape Sebastian PISTOL 0 100 KILOMETERS Crook Point BROOKINGS (a.k.a. Ferrelo) 0 60 MILES 42˚N

Oregon’s eighteen major littoral cells.

(A) Normal longshore seasonal movement of beach sediment (gray areas) in an Oregon coast littoral cell. (B) El Niños cause abnormally large northward transport of sand, resulting in focused erosion (red areas) at southern ends of cells, north of bounding headlands, and north of migrating inlets. The opposite response is found south of headlands, where northward displaced sand accumulates (blue area), causing the coast to advance (accrete) locally seaward. (figure courtesy of Dr. Paul Komar, Oregon State University; map, Jonathan Allan)

8 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries Cape Lookout State Park (continued from page 3) public citizens can construct riprap revet- on adjacent natural cobble beach sites. An ments or sea walls to protect their prop- unusual aspect of the study is the use of in- erties. Having often to deny such appli- novative tracking technology devices im- cations to the public, OPRD would have planted in some cobbles so that DOGAMI found itself in a politically awkward posi- coastal geomorphologist Jonathan Allan tion if it constructed a “hard” structure in and other researchers can track the move- the park. Furthermore, OPRD wanted to ment of cobbles to determine erosion avoid having an unnatural-looking struc- rates. ture separating the park grounds from its Taken together, the constructed dy- main attraction, the beach. OPRD decided namic revetment and artificial dune pro- to work with scientists from Oregon State vide shore protection with the desired ap- University and DOGAMI to construct pearance of natural features found along a dynamic revetment — dynamic in the Oregon’s coast. sense of consisting of gravel and cobbles After five years of protection, these that can be moved by storm waves, as op- “Design with Nature” structures in Cape posed to a conventional, static revetment Lookout State Park can be viewed as a built of large quarry stones. success. Had the structures not been built, The dynamic revetment in front of the recent winters storms would have washed park facilities, completed in 2000, is very into the park grounds and resulted in sub- much like a natural cobble beach and is stantial clean-up costs that in total may designed to mimic in appearance and dy- have exceeded the $125,000 cost of build- namic response the natural cobble beach- ing the cobble beach and dune. es found elsewhere in the park and along In addition, these dynamic revet- the Oregon coast. For additional defense ment and artificial dune prototypes pro- and in an attempt to restore the park to vide a unique opportunity to study their its former appearance, an artificial dune response to coastal processes, with the was constructed immediately landward potential for improvements in design cri- from the dynamic revetment. The dune teria. The innovative Cape Lookout State has a core of sand-filled geotextile tubes Park dynamic revetment project demon- covered with loose sand and planted dune strates that such structures, in the right grass. circumstances, can be effective, unobtru- In July 2001, a monitoring program sive shore protection, even on the high- was established along the structures and energy Oregon coast.

Design and construction of the Cape Lookout revetment

Revetment design was based on natural cobble beaches nearby in the park that had protected the dunes: mean cobble size of ~60 to 90 mm (-5.9Ø to -6.5Ø); mean slope of 11 to 14 degrees (1-in-5 to 1-in-4); elevation of 8 to 9 m NAVD88. Construction was carried out in two phases: (top) Unnatural-looking riprap shields Cape Phase 1— Phase 2— Lookout State Park restrooms from 1997- Artificial dune: Dynamic revetment/cobble berm: 1998 El Niño erosion. (middle photos) In 1999 Fill of 2750 0.7 m3 geotextile bags; Structure length = 300 m; construction began on the dynamic revet- Total elevation 7 to 9 m, NAVD’88. Crest elevation of 5.8 to 7.8 m, NAVD’88; ment. (bottom) The constructed revetment Beach slopes ~ 7 to 13 degrees. and dune mimic natural cobble beaches (Top four photos: courtesy of Oregon Parks and Recreation Department; diagram and bottom photo: Jonathan Allan) found elsewhere in the park.

9 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

Shoreline change Development on Oregon’s south coast requires in littoral cells new geologic mapping (continued from page 8) ould you buy land on a land- “These new maps will help guide locations, damaging adjacent proper- slide? Some eager and un- future development and mitigate hazards,” ties. Further south, erosion along the Wsuspecting new homeown- said Vicki McConnell, State Geologist and Garrison Lake shoreline near Port ers have in new coastal neighborhoods. Director of DOGAMI. “The maps will be Orford was especially acute, resulting Development on the south Oregon coast tools that can be used in many ways — in retreat of beaches there by 328–394 is booming (Curry County alone saw an from learning about the geologic history feet (100–120 m). almost 2% increase in population in the of an area, to natural resource and hazard Structures such as dams or harbors last year), and many people are buying assessment, to providing information for and development in beach areas can also homes and land without first checking intelligent land-use planning and growth.” cause the shoreline to change. Under- the geology underneath their property. In a departure from traditional 7.5´ standing littoral cells is therefore essential With growth comes increasing pressures quadrangle area mapping, the study area in planning for development and for pro- on land use and water supply, as well as will be defined by development patterns, tecting the beach. increasing potential for hazards such as topography, and drainage basins. This ap- Littoral cell study objectives focus on landslides, coastal erosion and ground- proach provides the best use of available monitoring and measuring alongshore water contamination. But development resources. New mapping will allow plan- and cross-shore spatial and temporal vari- and land-use decisions are being made ners to better understand groundwater ability, using methods such as morphol- with inadequate geologic maps. quantity and quality; landslide and coastal ogy surveys (e.g., beach-proﬁ le surveys, With the guidance of the Oregon erosion hazards; Quaternary deposit dis- Light Detection and Ranging [LIDAR] Geologic Map Advisory Committee, tribution and engineering properties; data surveys, and grain-size analyses) as DOGAMI’ Grants Pass Field Office staff soils; mineral resources; coastal features well as wave-runup assessments. will begin new, detailed geologic surface including headlands, sea stacks, and is- Littoral cell studies provide local, and subsurface mapping along a several lands; tsunami inundation, flooding, and state, and federal agencies scientific kilometers wide coastal strip from the earthquake hazards; and debris fans. information important for the safe es- California border to Ophir, about 35 miles “These new maps will mean better tablishment of homes and infrastruc- (56 km) north — an area targeted for un- planned, safer communities,” said McCon- ture along the coast. precedented growth in the next decade. nell. “It all starts with geologic mapping.”

Thank you! Know, know NANOOS The U.S. Integrated Ocean Observing System (IOOS) margin, are key components of IOOS. The Northwest is an emerging national infrastructure that seeks to Association of Networked Ocean Observing Systems meet society’s need for observing, understanding (NANOOS) is the emerging regional observing and predicting the ocean. Identified needs system for the Pacific Northwest (PNW). include detecting and forecasting oceanic NANOOS is developing nowcast and components of climate variability, predictive capabilities for the PNW facilitating safe and efficient marine environment, as well as interactive operations, ensuring national access to archival data, real-time security, managing resources data and selected forecasts. for sustainable use, preserving The Oregon Department of and restoring healthy marine Geology and Mineral Industries ecosystems, mitigating natural is a leading partner in the PNW hazards, and ensuring public health. pilot program (see pages 6-7). To Thanks to the Oregon Department of Land Regional ocean observing systems, access interactive NANOOS data, visit Conservation and Development (LCD) for which together will cover the entire U.S. coastal http://www.nanoos.org/. providing publications that helped us produce this issue. The NANOOS logo, by Mr. Tom Guthrie, a Tsimshian Tribal member, symbolically represents Visit the Oregon Coastal Atlas website for the protection of the coastal ocean ecosystem and the living beings of the Pacific interactive maps such as the one shown above: Northwest that depend on the coastal ocean. http://www.coastalatlas.net/.

10 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries Coastal issues publications and more available now from

The Orphan Tsunami of 1700: Japanese Clues to a The City of Parent Earthquake Seaside’s Tsunami in North America, Awareness USGS Professional Program: Paper 1707, by Brian Outreach Coastal Hazards and F. Atwater, Musumi- Assessment— Management Issues Rokkaku Satoko, How to imple- on the Oregon Satake Kenji, Tsuji ment an effective Coast, Coastal Yoshinobu, Ueda tsunami pre- Workshop, Lincoln Kazue, and David K. Yamaguchi, 2005, paredness out- City, Oregon, Field University of Washington Press, 133 pp., reach program, Trip to the Oregon $24.95. ISBN 0-295-98535-6. DOGAMI Open-File Coast 29 April 2004, Report O-05-10, by DOGAMI Open A Geographical Darci Connor for Oregon Department of File Report O-04-18, Information Geology and Mineral Industries, 2005, by Jonathan Allan, System (GIS) 78 pp., $10. Available on CD only. Paul Komar, and George Priest, Data Set of Beach Oregon Department of Geology and Morphodynamics Mineral Industries, 2004, 24 pp., $10. Derived from 1997, Dynamic revet- Available on CD only. 1998, and 2002 ments for coastal LIDAR Data for the erosion stabiliza- Central to Northern tion: Oregon Coast, A feasibility analy- A complete list of DOGAMI DOGAMI Open-File sis for application publications can be found online at: Report O-05-09 on the Oregon www.OregonGeology.com. by Jonathan C. Allan and Roger Hart, coast, DOGAMI Use the order form below or log on to Oregon Department of Geology and Special Paper 37, www.NatureNW.org to order. Mineral Industries, 2005, 16 pp., $10. by Jonathan Allan, Available on CD only. GIS data viewer Oregon Department on CD. of Geology and Mineral Industries, 2005, 67 pp., $10. Available on CD only.

NATURE OF THE NORTHWEST PUBLICATION ORDERS Mark desired titles on the list above and fi ll out this form. A complete list of publications is on the Nature of the Northwest homepage: http://www.NatureNW.org. You can order directly from the website or send this order form to The Nature of the Northwest Information Center, Suite 177, 800 NE Oregon Street, Portland, OR 97232-2162, or FAX (971) 673-1562. If you wish to order by phone, have your credit card ready and call (503) 872-2750. Payment must accompany orders of less than $50. Payment in U.S. dollars only. Publications are sent postpaid, except where noted. All sales are fi nal.

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11 www.OregonGeology.com from the Oregon Department of Geology and Mineral Industries

The dramatic southern Oregon coast near Myers Creek, south of Gold Beach, is characterized by prominent rocky headlands, coarse sand beaches and sea stacks. Places to see Sea stacks are remnants of headlands that have been eroded away by wave processes and subaerial weathering, leaving behind more resistant rock.

Gold Beach

(Photo: Jonathan Allan) Learn more about Oregon’s geology by going online at www.OregonGeology.com.

Historical marker recalls the Great Tsunami of 1700 A new historical marker, located at the Schooner Creek Wayside on U.S. Highway 101 south of Lincoln City, recalls the great earthquake and tsunami of Jan. 26, 1700, that destroyed Native American villages along the Northwest coast. The marker overlooks the portion of Siletz Bay where ancestors of the Confederated Tribes of Siletz Indians had a village that was lost to the earthquake and tsunami. Many State Agencies worked together on the marker for the common goal of history and safety. The Oregon Department of Geology and Mineral Industries oversaw the design and placement of the marker. Also involved were the Confederated Tribes of Siletz Indians and Chinook Winds Casino Resort, which helped organize a well-attended dedication ceremony on a beautiful September afternoon. (left) Delores Pigsley, Confederated Tribes of Siletz Indians Chairperson, and Dr. Vicki McConnell, Oregon State Geologist, speak at the tsunami marker dedication ceremony (Photo: DOGAMI archive). (right) The new historical marker. (Marker design by the Oregon Travel Information Council.)