Earthquakes risk in Massachusetts

Earthquake Characteristics in Massachusetts

Massachusetts is not known for frequent earthquakes, but the state does experience them. According to the USGS Earthquake Hazards Program, the Northeast region has a moderate seismic hazard. Earthquakes in Massachusetts are typically less frequent and lower in magnitude than those on the West Coast, but they can still cause damage. The state is rated level 2 out of 5 for earthquake risk, meaning there is a relatively low but not negligible risk.

Unlike California, Massachusetts does not sit on a major plate boundary. However, ancient faults and weaknesses in the Earth's crust remain. Because the crust in the eastern U.S. is older, colder, and more rigid, seismic waves can travel farther, so earthquakes are felt over a much wider area. A moderate earthquake centered in Massachusetts could be felt across several states.

The most significant historical earthquake in the region was the 1755 Cape Ann earthquake, estimated to have been around magnitude 6.0 to 6.3. It occurred off the coast of Cape Ann, northeast of Boston, and caused damage in Boston and surrounding towns. While an event of that size is rare, it demonstrates that Massachusetts can experience damaging earthquakes. Smaller earthquakes occur more often. For example, small tremors have been recorded in the Boston area, the South Shore, and the Connecticut River Valley.

Earthquakes can happen at any time of year; there is no 'earthquake season.' The entire state is exposed, but some areas may be more susceptible to stronger shaking. Eastern Massachusetts, including Boston, Cape Ann, and the South Coast, has historically experienced the most seismic activity. The Connecticut River Valley also has a history of minor earthquakes. Local soil conditions matter: soft soils, such as those in filled areas and river valleys, can amplify shaking, while bedrock areas may shake less. The Massachusetts Emergency Management Agency (MEMA) provides preparedness information for all hazards, including earthquakes.

How Earthquakes Affect Homes in Massachusetts

Earthquake damage to homes in Massachusetts is typically caused by ground shaking. Even moderate earthquakes can crack foundations, walls, and chimneys. Older homes, especially those with unreinforced masonry (brick or stone) and brick chimneys, are more vulnerable. Unsecured water heaters, furnaces, and appliances can move, causing gas leaks or fires. Objects falling from shelves and broken windows are common injuries during shaking.

Massachusetts has a large stock of older housing. Many homes were built before modern seismic codes. While the state does have building codes that include some seismic provisions, older homes may not meet them. The most common damage includes:

• Cracked or collapsed chimneys
• Foundation cracks and shifting
• Broken windows and falling objects
• Gas and water line breaks
• Damage to porches, decks, and unreinforced walls

Insurance considerations: Standard homeowners insurance policies typically do not cover earthquake damage. You may need a separate earthquake insurance policy or an endorsement. In Massachusetts, earthquake insurance is available from many insurers, but it often comes with a high deductible (often 5% to 15% of the home's insured value). Because earthquakes are rare in the state, many homeowners choose not to buy coverage. However, if you live in an older home or an area with higher risk, it may be worth discussing with your insurance agent. Ready.gov notes that earthquake insurance can help protect your investment. FEMA also provides guidance on earthquake insurance and mitigation.

How to Prepare Your Home for Earthquakes

Taking steps to strengthen your home can reduce earthquake damage and keep your family safer. Here are concrete actions you can take:

• Secure heavy furniture and appliances to wall studs using brackets, straps, or anchors. This includes bookcases, televisions, and refrigerators.
• Brace and strap your water heater. Use metal straps to anchor it to wall studs. Install flexible gas connectors on gas appliances.
• Install latches or childproof locks on cabinets to keep dishes and supplies from falling out.
• Retrofit your chimney. Unreinforced brick chimneys are especially vulnerable. Have a professional brace or reinforce it, or consider replacing it with a reinforced or metal chimney.
• Reinforce your foundation. If your home has a cripple wall or raised foundation, consider bolting the house to the foundation and bracing the cripple wall with plywood.
• Anchor large electronics and artwork. Use earthquake putty or straps to secure items on shelves.
• Consult a licensed engineer or contractor to assess your home's structural weaknesses and recommend a seismic retrofit.
• Create a family emergency plan. Practice 'Drop, Cover, and Hold On' drills. Identify safe spots in each room.
• Assemble an emergency kit with water, non-perishable food, medications, flashlight, first aid, and important documents.
• Know how to turn off gas and electricity at your home. Only turn off gas if you smell or hear a leak.
• Review your insurance coverage and consider whether earthquake insurance is right for you.

For more detailed guidance, see Ready.gov – Earthquakes and FEMA Earthquake Safety.

Frequently Asked Questions

Are earthquakes common in Massachusetts?

No, earthquakes are infrequent in Massachusetts. The state experiences minor earthquakes occasionally, but damaging earthquakes are rare. The most significant historic event was the 1755 Cape Ann earthquake. The USGS notes that the Northeast has a moderate seismic hazard, so while the risk is lower than in the western U.S., it is not zero.

Does homeowners insurance cover earthquake damage in Massachusetts?

Standard homeowners insurance policies typically do not cover earthquake damage. You would need to purchase a separate earthquake policy or add an endorsement. Deductibles for earthquake coverage are often higher than standard deductibles. Check with your insurance agent to understand your options.

What should I do during an earthquake in Massachusetts?

If you feel shaking, Drop, Cover, and Hold On. Get under a sturdy table or desk, protect your head and neck, and hold on until shaking stops. If outdoors, move away from buildings, streetlights, and power lines. After the shaking, check for injuries and damage, and be prepared for aftershocks. Follow instructions from MEMA and Ready.gov.

Official Resources

• Massachusetts Emergency Management Agency (MEMA)
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety