EARTHQUAKES IN NEVADA
and how to survive them
New: 2010 Revision, 1.3 Mb PDF
Nevada Bureau of Mines and Geology
UNR Seismological Laboratory
Nevada Division of Emergency Management
Nevada's Earthquake Hazard
The State of Nevada is located in "earthquake country". It lies within the Basin and Range province, one of the most seismically active regions in the United States. Along with California and Alaska, Nevada ranks in the top three states subject to the most large earthquakes over the last 150 years. Figure 1 shows the seismicity recorded in Nevada from 1852-1988. Magnitude 3 and 4 earthquakes are commonly felt, but rarely cause damage. Minor to moderate damage can accompany a magnitude 5 or 6 event, and major damage commonly occurs from earthquakes of magnitude 7 and greater. Although earthquakes don't occur at regular intervals, the average frequency of earthquakes of magnitude 6 and greater in Nevada has been about one every ten years, while earthquakes of magnitude 7 and greater average once every 27 years.
Geologically young faults, which are the sources of earthquakes, can be found throughout the state (fig. 2). Although the largest historical earthquakes occurred some distance from population centers, no part of the state is far from a potential source of large earthquakes. Large earthquakes occurring along the borders of Nevada, such as the 1872 Owens Valley earthquake in California (magnitude 7 3/4 - 8), can also cause strong shaking and damage in Nevada.
Large earthquakes have occurred in Nevada in the recent past and more will occur in the near future. This pamphlet suggests simple, inexpensive steps that can be taken before, during, and after an earthquake to minimize personal injury and property damage.
|Selected Earthquakes in Nevada (1)|
Date Magnitude Location Nearest Community(2) ---- --------- -------- --------------------- 1845? or 1852? 7.3? Pyramid Lake? Wadsworth? Mar. 15, 1860 6.8? Carson City Carson City Dec. 27, 1869 6.7 Olinghouse Wadsworth Dec. 27, 1869 6.1 Carson City Carson City Jun. 3, 1887 6.3? Carson City Carson City Apr. 24, 1914 6.4 Reno area Reno Oct. 3, 1915 7.6 Pleasant Valley Winnemucca Dec. 21, 1932 7.2 Cedar Mountain Gabbs Jan. 30, 1934 6.3 Excelsior Mtns. Mina Dec. 29, 1948 6.0 Verdi area Verdi May 24, 1952 5.0 Lake Mead area Boulder City Jul. 7, 1954 6.6 Rainbow Mtn. Fallon Aug. 8, 1954 7.0 Rainbow Mtn. Fallon Dec. 16, 1954 7.2 Fairview Peak Fallon Dec. 16, 1954 6.8 Dixie Valley Fallon Sep. 22, 1966 6.1 Clover Mountain Caliente Jun. 29, 1992 5.5 Little Skull Mtn. Amargosa Valley Sep. 12, 1994 6.0 Double Spring Flat Gardnerville
Earthquake deaths and injuries are seldom caused directly by movement of the ground. Most frequently, injuries are caused by collapse of buildings; flying glass; overturned bookcases, furniture, and appliances; and fires from broken chimneys, broken gas lines, and downed electrical lines. Preparing for earthquakes only takes a little time, foresight, and common sense to imagine what would happen if the ground starts to shake, and how to mitigate or prepare for the consequences of shaking.
By planning and practicing what to do before an earthquake occurs, you and your family can learn to react correctly and automatically when the first jolt or shaking begins. This can turn the tendency to panic into lifesaving action.
Following a large earthquake, it may be 72 hours or longer before outside emergency assistance can reach everyone, so any efforts towards mitigating seismic hazards and being prepared to be self sufficient immediately afterward are prudent.
What to do before an earthquake
- Have a battery powered radio, flashlight, water, and first aid kit in your home. Make sure everyone knows where they are stored. Keep fresh batteries on hand.
- Know the location of gas and water shutoff valves and the electric fuse or circuit breaker box. Make sure responsible members of your family learn how to turn them off. Keep crescent and pipe wrenches handy for an emergency.
- Remove heavy objects from high shelves and store them on the floor or bottom shelves. Don't hang heavy picture frames or mirrors over beds. Locate beds away from windows. Do not put hanging plants or light fixtures where they can swing and hit a window or come off their hooks.
- Put one or more straps around water heaters and gas furnaces and attach them securely to walls to keep natural gas hookups from breaking. Flexible gas connectors can also be used. Bolt the supports to the floor. Block rollers on refrigerators, washers, and other heavy appliances.
- Anchor securely to walls cupboards and high bookcases that might topple. Keep cupboards and cabinets latched.
- Store containers of dangerous materials, such as flammable liquids and poisons, in a secure place where they cannot fall and break open.
- With your family, identify dangerous areas and places to take cover for each room inside your house. Point out hazardous areas outside as well, such as near the chimney or power lines.
- Keep a few days of nonperishable food on hand in your home (canned goods are ideal) and enough water for each person for a week. If you take medicine regularly, have an extra supply on hand.
- Devise a plan for reuniting your family after an earthquake in the event that anyone is separated. Family members should know the locations of the nearest medical, fire, and police facilities.
- When building or remodeling a house, be sure to provide adequate bracing against horizontal forces. Make sure that the foundations are adequate and that the house is securely tied to the foundation. Add bracing to support chimneys and air conditioners, especially on rooftops. (For further information see references on last page.)
- Mobile homes can fall off their supports during an earthquake. To avoid this, leave the tires on or brace the supports.
- Do not locate buildings within 50 feet of active faults where surface fractures secondary to the fault may occur.
- Employers should check out offices and factories to make sure employees are out of danger from falling objects. Keep exit ways clear so that they will not become cluttered with debris and will be usable after an earthquake.
- Teachers should check classrooms for potential hazards, such as heavy displays or aquariums, and make sure they are away from areas where students will be taking cover.
What to do during an earthquake
- Your actions are critically important. Act immediately when you feel the ground or building shake, keeping in mind that the greatest danger is falling debris. Don't worry about being embarrassed if you take cover under a desk or table.
- Stay calm.
- As a general rule, don't run in or out of buildings. If indoors, stay indoors; if outdoors, stay outdoors. Many injuries occur as people enter or leave buildings. If indoors, wait for shaking to stop, then cautiously move outside.
- If you are indoors, stand against a wall near the center of the building, in a doorway, or get under a desk or other sturdy furniture. Stay away from windows which can shatter, outside doors, and objects hanging from ceilings, such as light fixtures.
- If you are outdoors, stay in the open, and keep away from buildings, electric wires, and trees.
- If you are in a tall building, do not attempt to evacuate; seek safety where you are. Don't be surprised if the electricity goes out, and elevator, fire, and burglar alarms go off. Expect to hear noise from breaking glass and falling objects. Do not use elevators.
- If you are in an unreinforced masonry building or other hazardous structure, you may feel it is better to take a chance on leaving the building than staying inside. Leave quickly but cautiously, being alert for falling bricks, electric wiring, and other hazards.
- If you are in school, get under a desk, facing away from windows. If you are on the playground, stay away from buildings.
- If you are in a moving car, safely stop the car and remain inside. Avoid stopping near or under buildings, overpasses, and utility wires.
- If you are in a crowded place, stay calm and urge others to do the same; take cover under sturdy furniture; in an auditorium, crouch on the floor between chairs and cover head.
- If in a steep canyon or near a steep slope, watch out for rock falls and landslides.
What to do after an earthquake
- Check yourself and people nearby for injuries. Provide first aid if needed.
- Check for fires and fire hazards. Check burning wood stoves and stove pipes. Put out fires immediately if you can. Approach chimneys with caution and inspect for damage. Do not use fireplaces unless the chimney is undamaged and without cracks.
- Check gas, electric, and water lines. If damaged, shut off valves. Tum off appliances. Do not light matches or candles. Check for gas leaks by odor only. If a gas leak is detected, open all windows and doors, leave immediately, and report to authorities.
- Do not touch power lines, electric wiring, or objects in contact with them.
- Turn on the radio for emergency instructions. Do not use the telephone unless there is a severe injury.
- Wear sturdy shoes to protect against shattered glass and debris.
- Do not flush toilets until sewer lines are checked.
- Open closet doors and cupboards cautiously, because objects may fall outward on you.
- Stay out of damaged buildings. Collapses can occur without much warning and there are dangers from gas leaks, electric wiring, and broken glass.
- Be reassuring and helpful to children and others who may suffer psychological trauma from the earthquake. Do not spread rumors.
- Identify emergency water supplies, such as the water heater.
- If driving immediately after an earthquake, watch for hazards created by the earthquake like fallen objects, downed electric wires, or blocked roadways.
- EXPECT AFTERSHOCKS. They may cause additional damage.
For further information on faults, earthquakes, and emergency management in Nevada.
The recommendations and suggestions included in this document are intended to improve earthquake preparedness; however, they do not guarantee the safety of an individual structure or facility. The State of Nevada does not assume liability for any injury, death, or property damage that occurs in connection with an earthquake.
THIS PAMPHLET PREPARED BY:
Craig dePolo, Alan Ramelli, and Diane dePolo