CERT Hazard Annexes Participant Manual [This page intentionally left blank] • CERT Hazard Annex: Avalanche Participant Manual [This page intentionally left blank] CERT Hazard Annex: Avalanche Participant Manual INTRODUCTION An avalanche is a large mass of snow rapidly moving down a mountainside that can travel as fast as 80 miles per hour (mph). When it stops, the snow debris left behind can become as solid as concrete. While primarily a phenomenon in the western United States, avalanches can also occur in mountainous regions of the Northeast. Avalanche Impacts There are many impacts on people, property, and infrastructure associated with avalanches. • Typically, a combination of asphyxia, trauma, and hypothermia cause avalanche fatalities. In an average winter, 28 people die from avalanches in the United States. • Avalanches disrupt transportation, power and other services, and cause economic losses from damages to structures and roadways. Avalanche Facts Avalanches can occur in dry or wet snow as either slab or sluff avalanches. A dry snow avalanche occurs in dry snow at below freezing temperatures. A wet snow avalanche usually occurs when warm air temperatures, sun, and/or rain cause water to percolate through the snowpack and decrease the strength of the snow. In some cases, this changes the mechanical properties of the snow. Dry avalanches often fail because of an increase in load compared to wet slabs that fail because of a decrease in layer strength. • Slab avalanches: A “slab” is a cohesive plate of snow that slides as a unit on the snow underneath. - Dry slab avalanches are the deadliest and account for nearly all the avalanche deaths in North America. The bonds holding a slab in place typically fracture at 220 mph and it appears to shatter like a pane of glass. Dry slab avalanches can lie patiently, teetering on the verge of catastrophe, sometimes for days to even months. - Wet slab avalanches often occur during prolonged warming events and/or rain-on-snow events. Wet slab avalanches can be very destructive, and they often occur first at lower elevations and areas with a shallower snowpack. • Sluff avalanches: Also known as loose snow or point release avalanches, sluffs usually start from a point and fan outward as they descend. Sluffs kill very few people because they tend to be small and tend to fracture beneath you as you cross a slope instead of above you as slab avalanches often do. Once initiated, wet snow avalanches tend to travel much more slowly than dry snow avalanches. Wet snow avalanches are harder for a person to trigger than a dry slide. Therefore, wet avalanches do not account for nearly as many avalanche fatalities as dry August 2019 Page AV-1 CERT Hazard Annex: Avalanche Participant Manual snow avalanches. However, they still account for a sizeable percentage of avalanche fatalities—especially to climbers—in maritime climates. A typical wet avalanche travels between 10 and 20 mph while a typical dry snow avalanche travels at speeds of between 60 and 80 mph. About 90 percent of all avalanches start on slopes of 30 – 45 degrees. Avalanche fatalities in the United States tend to occur in locations with mountains and significant snow. This includes the western states and Alaska, but they also occur in northeastern states. Avalanche Preparedness • Training in how to recognize and avoid avalanches is critical for anyone who goes where avalanches are possible. The U.S. Forest Service (USFS) National Avalanche Center states, “The best way to stay safe is to know the conditions, get the training, carry rescue gear, and stay out of harm’s way.” Contact your local or regional avalanche center for a list of avalanche classes. • Obtain proper equipment and training to support rescue, mitigate head injuries, and create air pockets. Everyone should travel in pairs, obtain avalanche survival training, carry a working multi-function (i.e., transmit and receive) avalanche beacon on their body, a small portable shovel and an avalanche probe in a backpack. Also, consider wearing a helmet and carrying an avalanche airbag. • Consider the following precautions when in avalanche-prone areas: - Avoid slopes steeper than 30 degrees. - Avoid runout zones under slopes steeper than 30 degrees. - Pay attention to immediate warning signs, which include recent avalanches, shooting cracks, and “whumpfing” sounds. - Avoid particularly dangerous areas, slopes, and terrain even if the regional advisory is low. - Note that avalanche prone areas near highways are usually marked with signs. • Do not stop your car in these areas. • Keep moving until out of the avalanche prone area, as steep embankments along roadsides are particularly susceptible to avalanches. • Sign up for local alerts and warnings. Local areas with avalanche terrain may have warning systems and evacuation plans for serious avalanche conditions. • Monitor local news and weather reports. • The USFS and its 14 regional avalanche centers issue Advisories and Warnings in dangerous conditions using the five category Danger Scale to communicate travel advice, the likelihood of avalanches, and the size and distribution of avalanches. Table 1 below displays the meaning of the North American Public Avalanche Danger Scale levels. August 2019 Page AV-2 CERT Hazard Annex: Avalanche Participant Manual Table 1: North American Public Avalanche Danger Scale Likelihood of Avalanche Size and Danger Level Travel Advice Avalanches Distribution Natural and human- Large to very large Avoid all avalanche Extreme triggered avalanches avalanches in many terrain. certain. areas. Very dangerous Natural avalanches Large avalanches in avalanche likely; human- many areas; or very High conditions. Travel in triggered avalanches large avalanches in avalanche terrain is very likely. specific areas. not recommended. Dangerous avalanche Small avalanches in conditions. Careful many areas; or large Natural avalanches snowpack avalanches in possible; human- Considerable evaluation, cautious specific areas; or triggered avalanches route-finding, and very large likely. conservative avalanches in decision-making isolated areas. essential. Heightened avalanche conditions Natural avalanches Small avalanches in on specific terrain unlikely; human- specific areas; or Moderate features. Evaluate triggered avalanches large avalanches in snow and terrain possible. isolated areas. carefully; identify features of concern. Generally safe avalanche Natural and human- Small avalanches in conditions. Watch for Low triggered avalanches isolated areas or unstable snow on unlikely. extreme terrain. isolated terrain features. • If you live in an area with a risk of an avalanche, consider consulting a professional about placement and mitigation structures such as retention structures, redistribution structures, and retarding or catchment structures. During an Avalanche The suddenness of an avalanche requires that people be prepared to act quickly. In the event you experience an avalanche, you must put implement your training and operate your equipment effectively and efficiently. • If buried in an avalanche, before the snow stops moving, cup your hand in front of your face to clear airspace and expand your chest if possible. Helmets can provide the necessary airspace if still in place. Also, relax to conserve oxygen. August 2019 Page AV-3 CERT Hazard Annex: Avalanche Participant Manual DO NOT YELL. Rescuers will not be able to hear you even though you will be able to hear them. After an Avalanche • If an avalanche buries your partner, make a brief call to 9-1-1 before you initiate an immediate search. Rescued victims will likely require immediate medical attention. Treatment for suffocation, hypothermia, traumatic injuries, and/or shock is commonly required for avalanche victims. • Stay away from avalanche areas. There may be danger of additional slides. • If a building has been hit by an avalanche, check for signs of structural damage. Consider having it assessed by a professional. August 2019 Page AV-4 [This page intentionally left blank] [This page intentionally left blank] CERT Hazard Annex: Earthquake Participant Manual [This page intentionally left blank] CERT Hazard Annex: Earthquake Participant Manual INTRODUCTION An earthquake is the sudden, rapid shaking of the earth, caused by the breaking and shifting of subterranean rock as it releases strain that has accumulated over a long time. Earthquake hypocenters are usually less than 50 miles below the Earth’s surface and are accompanied and followed by a series of vibrations. The epicenter—the point where an earthquake originates—is directly above the hypocenter on the surface. Earthquakes occur without any obvious warning. There is no seasonal or yearly cycle of earthquake occurrence; earthquakes can happen at any time. An earthquake may last for seconds or minutes, while aftershocks may occur hours, days, or months after the main earthquake. Earthquake Impacts Earthquakes threaten lives, property, and the environment. Shaking ground from an earthquake can: • Cause buildings to move off their foundations or collapse; • Send household items flying, making them dangerous projectiles; • Damage utilities and roads; • Cause fires and explosions; and • Cause structural instability, such as dam failures that can trigger flash floods. Earthquake Facts Earthquakes can trigger other hazards such as avalanches, fires, floods, landslides, and tsunamis. It is very important to listen for emergency instructions after the shaking stops. Many parts of the United States carry significant