Earthquakes: What You Should Know
Why talk about earthquakes?
Earthquakes strike suddenly and without warning. They can occur throughout the year at any time of day or night. Each year 70-75 damaging earthquakes occur around the world. In Maine we experience an average of 5 earthquakes per year.
Forty-five states and territories in the United States are at moderate to very high risk of earthquakes. Maine is classified as a moderate risk state.
How can I protect myself in an earthquake?
Ground vibrations during an earthquake are seldom the direct cause of death or injury. Most earthquake-related injuries and deaths result from collapsing walls, flying glass, and falling objects caused by the ground shaking. It is extremely important for a person to move as little as possible to reach the place of safety he or she has identified, because most injuries occur when people try to move more than a few feet during the shaking.
Much of the damage caused by earthquakes is predictable and preventable. We must all work together in our communities to apply our knowledge to enact and enforce up-to-date building codes, and avoid building in hazardous areas, such as those prone to landslides. We must also look for and eliminate hazards at home. We must also learn and practice what to do if an earthquake occurs.
Facts and Fiction
- Fiction: During an earthquake, you should get into a doorway for protection.
- Fact: In modern homes, doorways are no stronger than any other part of the structure and usually have doors that will swing and can injure you. During an earthquake, you should get under a sturdy piece of furniture and hold on.
- Fiction: During an earthquake, the earth cracks open and people, cars, and animals can fall into those cracks.
- Fact: The earth does not crack open like the Grand Canyon. The earth moves and rumbles and, during that movement, small cracks can form. The usual displacements of the earth during an earthquake are caused by up-and-down movements, so shifts in the height of the soil are more likely than chasm-like cracks.
- Fiction: Someday there will be beachfront property in Arizona.
- Fact: The ocean is not a great hole into which California can fall, but is itself land at a somewhat lower elevation with water above it. The motion of plates will not make California sink – California is moving horizontally along the San Andreas Fault and up around the Transverse Ranges.
- Fiction: We have good building codes so we must have good buildings.
- Fact: Many of Maine’s buildings were built prior to 1950 when municipalities in Maine had no known building codes. These buildings are called “pre-code” structures. From 1950 – 2009, individual towns and cities had a variety of building codes, but there was no statewide standard. In 2010, Maine adopted the International Building Codes which will be enforced in all municipalities in Maine with a population of 2000 people or more.
For More Information
- Maine Geological Survey Earthquake Page
- FEMA: Are You Ready? (Earthquakes)
- USGS: Maine Earthquake Information