A shaking or trembling of the crust of the earth caused by underground volcanic forces or by breaking and shifting of rock that registers 5.5 or more in magnitude. It results in considerable property damage and possible casualties. The effects of earthquakes are largely dependent on the strength of the earthquake as measured by the Richter or other magnitude scales, the concentration of population and extent of development in the impacted area. Slight earthquakes do little damage. Utility services could be interrupted, transportation routes cut off, fire potential could increase with gas lines rupturing, live power lines could break and emergency responders could be unable to reach scenes of incidents.
Personal injury caused by falling debris is also a consideration.
While Maine has experienced numerous measurable earthquakes in the last 100 years, none have caused substantial damage. However, their distribution throughout the State indicates vulnerability is statewide. Metropolitan areas are subjected to far more structural damage than rural areas because of the density and design of urban buildings, especially multi-story structures. Buildings constructed in high risk areas should conform to standards of safety for earthquakes. Emergency planning for earthquakes should include search and rescue, medical assistance, crisis counseling, evacuation, sheltering and mass care, and reduction of the potential problems caused by falling debris, fire, utilities, and hazardous materials.