Earthquakes are hard to predict. Scientists have a pretty good idea why they happen and we can trace a history of when they have happened in the past. As of yet, however, we cannot tell when an earthquake will hit a given area. It does us some good to know that there is a certain percentage chance of a major earthquake occurring within the next 30 years but it would be more useful if we knew what would happen tomorrow. Since we don't, it makes sense to be ready for a major earthquake to happen at any time. This is true whether you live in an area that has earthquakes frequently, or only every few hundred years. You may have less chance of being hit tomorrow, but the consequences could be worse, because nobody is expecting it.
What to Expect
So, what happens when an earthquake hits? Well, it kind of depends how big an earthquake. Kind of. News reports from around the world show that it is not just the size of an earthquake that determines the damage. An earthquake that will cause little damage one place may be a major disaster somewhere else. There are a number of factors that affect how much damage a given earthquake will cause. Obviously one that occurs in a populated area will be more damaging than one in the wilderness. Soft soils will shake a lot more than bedrock, and cause a lot more damage. Building methods will also affect how well a building will ride out the quake. Check out the Quake Effects display to find out how all these factors interact to produce a unique pattern of damage in each quake.
- Know your risk.
- Different places definitely have a different chance of a big earthquake. Certain areas have many more earthquakes than others. The Pacific Rim has been known as the "Ring of Fire" because there is a lot of volcanic activity and earthquakes around the edge of the Pacific. (See the display on Plate Tectonics to understand why.) However that does not mean that other areas are not at risk. Some areas are susceptible to earthquakes only rarely, but they can be just as damaging when they do occur. These Seismic Risk Maps will give you some idea of your chance of being in a big earthquake.
- In a given earthquake, different localities will have different amounts of damage. The underlying soils have a lot to do with how well a building will do. This was clearly shown in the 1989 Loma Prieta Earthquake , where adjoining neighborhoods in San Francisco fared quite differently.
- A third factor that can make a big difference is the type of building and the construction methods used. Similar earthquakes have had very different results in places where different building methods are used. Moderate earthquakes cause widespread collapse of buildings made of masonry, where reinforced wooden buildings do just fine.
- Prepare your House.
- Make sure that your house is bolted to the Foundation. In past earthquakes houses have been severely damaged because they were knocked off their foundation. Had they been bolted down, they could have ridden out the quake with a lot less damage.
- Brace your hot water heater securely. A falling hot water heater can cause injuries or can start a fire. The water in the tank can also serve as an emergency supply if water mains have been broken or damaged in the quake.
- Secure furniture such as bookcases and picture frames to the wall.
- Install cabinet latches to prevent heavy or breakable items from spilling out during a quake. Be careful opening cabinets after a quake as items may have fallen against the doors.
- Make sure that beds are not located in hazardous positions. Windows and heavy objects should not be located where they can fall on you, especially on your head, while you are sleeping.
- Know how to turn off the gas, water and electricity if necessary. You may need a special tool for the gas. Keep it where you will be able to find it quickly in an emergency. Authorities generally advise against turning off the gas unless you smell gas or have reason to believe that there may be a leak. You should check with your local utility. You may need to wait for the utility to turn the gas back on if you turn it off. After a quake this could take some time.
- Emergency Supplies Have enough food and water on hand to last several days. You may be on your own for that long, or longer, before authorities can get a relief system set up.
Have your emergency supplies in one place so you can get to them quickly after the earthquake. Many people use a large storage box, one with wheels could come in very handy. It is a good idea to check your supplies periodically, to make sure that everything is still there and usable. Put fresh food, water and batteries into the kit and use the old ones.
Since you may be stranded away from home, keep similar kits in your car and at work or school. Some school districts require each child to have an emergency kit at school in case their parents are unable to pick them up for a day or two.
- Water - allow one gallon per person per day. Remember that water mains may be broken, contaminating the water supply or cutting it off entirely. Your hot water heater can also provide a supply of water.
- Food - choose items that are compact, nutritious, do not need refrigeration, and can be prepared under adverse conditions with a minimum of cooking.
- Fire Extinguisher
- Portable Radio and extra batteries - So you can hear official bulletins and news.
- Flashlights and extra batteries.
- First Aid kit.
- Camp stove with fuel and matches.
- Blankets, warm clothing and sturdy shoes.
- Large, sturdy plastic bags.
- Have an Emergency Plan
- Make sure that all family members know what to do in an earthquake.
- Decide on some safe places at home, work or school where you can ride out the quake.
- Arrange an emergency phone contact. Ideally this would be somebody out of the area that will be able to serve as a central clearing point for information about family members and friends. Phone lines might be out or restricted but it may be easier to call long distance than locally. If family members are separated they can all check in with the contact to exchange information. Make sure that friends and relatives know to call this number. The authorities may ask people not to tie up phone lines that are needed for emergency purposes, so keep your calls brief.
- Learn First Aid
- Talk to your neighbors about how you can all work together to prepare and survive the next big earthquake. A prepared neighborhood will do much better than an unprepared one and will be less likely to need outside help, which may be slow in arriving.
- Stay Calm - remember your earthquake plan and follow it.
- Take shelter under a sturdy table or in an area protected from falling objects and breaking glass.
- Do not run out of a building. The most dangerous place to be could be right next to a building where you are exposed to falling glass, bricks, or power lines.
- If outside, move away from buildings or power lines. Be careful about standing in the street. Drivers could panic or lose control of their cars during a quake.
- If you are driving, slow down and pull over if it is safe to do so. Watch out for overpasses, bridges and other objects that might collapse. Avoid these if possible.
- Help Injured People.
- Check for fires
- Call for emergency help if it is needed to help injured or trapped people or to fight fires. If the phones do not work, send somebody to inform police or firefighters.
- Check for damaged gas or electrical lines. Notify emergency personnel of any problems you find.
- Turn off the gas if you have reason to believe that there is a leak in your house.
- Keep people away from downed power lines.
- Check buildings for damage and hazards.
- Clean up broken glass or other hazardous materials that may have spilled. Keep people away from hazards until they can be cleaned up.
- Aftershocks are common. They may be strong enough to cause further damage, especially to already weakened buildings. Stay away from anything that could fall in an aftershock.
- If the power is off, plan to eat foods first that are in danger of spoiling. Keep your refrigerator closed as much as possible to conserve the cold.
- For the duration of the emergency, keep cool; help each other; keep informed but don't let the media hype or rumors blow things out of proportion; get help when you need it; be patient and as much as possible be self sufficient.