Earthquakes risk in Pennsylvania

Earthquake Characteristics in Pennsylvania

Pennsylvania is not located near a major tectonic plate boundary, so it does not experience the frequent, powerful earthquakes that strike states like California or Alaska. According to the USGS Earthquake Hazards Program, the Commonwealth has a relatively low earthquake hazard, which is why it is rated level 1 out of 5 on the National Risk Index. However, "low" does not mean "none." Small earthquakes do occur, and some have been felt by residents.

The most seismically active part of Pennsylvania is the southeastern corner, including the Philadelphia metropolitan area and the Delaware River Valley. This region has a slightly higher chance of experiencing modest shaking because of ancient faults that run through the area. Other parts of the state, such as the northwest near Erie and the central mountains, see occasional minor quakes as well. Most earthquakes in Pennsylvania are magnitude 2 to 3, which are typically felt only by people indoors and rarely cause damage.

Unlike hazards such as floods or winter storms, earthquakes have no season. They can happen at any time of year, day or night. The key point for homeowners is that while the overall risk is low, the possibility exists, and it is smart to know what to do before, during, and after a quake.

How It Affects Homes

In Pennsylvania, the vast majority of earthquakes are too small to cause structural damage. When a slightly larger quake does occur, typical home impacts include cracked plaster or drywall, items falling off shelves, and minor foundation cracks. Older homes, especially those with brick or stone masonry, may be more vulnerable to shaking because they were not built with modern seismic codes. Unreinforced chimneys are particularly at risk of cracking or toppling.

Because the risk is low, most homeowners in Pennsylvania do not carry earthquake insurance. Standard homeowners and renters insurance policies typically exclude earthquake damage. If you want coverage, you would need to purchase a separate earthquake policy or endorsement. Given the low likelihood of a damaging quake, many insurers may not even offer dedicated earthquake coverage in the state, so it is worth checking with your agent. The FEMA Earthquake Safety page notes that most residential damage from earthquakes in low-hazard areas is non-structural, such as broken windows or fallen objects, which are usually covered by your regular policy if they result from a covered event.

It is also important to understand that earthquake damage is not covered by the National Flood Insurance Program or most standard disaster assistance programs. FEMA may provide individual assistance after a presidentially declared disaster, but that is not guaranteed.

How to Prepare Your Home

Even in a low-risk state like Pennsylvania, simple steps can reduce the chance of injury and property damage. The Ready.gov earthquake guidance recommends the following actions:

• Secure heavy furniture and appliances. Anchor bookcases, tall cabinets, and water heaters to wall studs. Use flexible connectors for gas appliances.
• Strap your water heater. A falling water heater can cause a gas leak or water damage. Secure it with metal straps.
• Fasten shelves and picture frames. Use closed hooks or museum putty to keep items from falling.
• Know how to shut off gas and water. Teach everyone in the household where the shutoff valves are and how to use them. Only shut off gas if you smell or hear a leak.
• Create an emergency kit. Include water, non-perishable food, flashlight, batteries, first aid supplies, medications, and a battery-powered radio.
• Practice "Drop, Cover, and Hold On." During an earthquake, drop to your hands and knees, cover your head and neck under a sturdy table, and hold on until shaking stops.
• Identify safe spots in each room. Choose places away from windows, mirrors, and tall furniture.
• Consider a professional inspection. If you live in an older home, a structural engineer can identify potential weaknesses, such as unreinforced masonry or a poorly braced chimney.

These measures are inexpensive and can also help with other hazards like severe storms or tornadoes, making them a good investment for any Pennsylvania homeowner.

Frequently Asked Questions

Does Pennsylvania have earthquakes?

Yes, but they are usually small. The USGS records occasional earthquakes in Pennsylvania, most with magnitudes below 3.0. These quakes are often felt only by a few people and cause no damage. The southeastern part of the state has the highest earthquake hazard, but even there, the risk is considered low compared to active regions like the West Coast.

Is earthquake insurance required in Pennsylvania?

No, earthquake insurance is not required by law in Pennsylvania. Standard homeowners insurance policies typically do not cover earthquake damage, so if you want protection, you would need to buy a separate policy or endorsement. Because the risk is low, many homeowners choose not to purchase it. Check with your insurance agent to see if coverage is available and whether it makes sense for your situation.

What should I do during an earthquake in Pennsylvania?

Follow the same safety steps recommended everywhere: Drop, Cover, and Hold On. Get down on your hands and knees, cover your head and neck with your arms or a sturdy piece of furniture, and hold on until the shaking stops. If you are indoors, stay there. If you are outdoors, move to an open area away from buildings, trees, and power lines. After the shaking stops, check for injuries and damage, and be prepared for possible aftershocks.

Official Resources

• Pennsylvania Emergency Management Agency (PEMA) – State agency for emergency preparedness and response.
• USGS Earthquake Hazards Program – Science and real-time data on earthquakes.
• Ready.gov – Earthquakes – Federal preparedness guidance for earthquakes.
• FEMA Earthquake Safety – Risk management and safety information.