Earthquakes risk in South Carolina

Earthquake Risk in South Carolina

South Carolina is not typically thought of as earthquake country, but it has a documented history of significant seismic activity. The state’s earthquake risk is rated level 3 out of 5 by FEMA, indicating a moderate hazard. The most active area is the coastal plain, particularly the Charleston and Summerville region, where the 1886 Charleston earthquake (estimated magnitude 7.3) caused widespread damage. According to the USGS Earthquake Hazards Program, this area remains the most seismically active in the eastern United States. Other parts of the state, including the Piedmont and the fall line near Columbia, can experience smaller earthquakes, but the Lowcountry faces the highest risk.

Earthquakes in South Carolina can occur at any time of year; they are not seasonal. The state’s geology features ancient faults that occasionally reactivate. While most earthquakes are small and cause little damage, the potential for a larger event exists. Eastern U.S. earthquakes, including those in South Carolina, are often felt over a much larger area than similar-sized earthquakes in the West because the bedrock is older and more continuous. The South Carolina Emergency Management Division (SCEMD) works to prepare communities and provides resources for residents.

The South Carolina Emergency Management Division notes that the state has experienced several damaging earthquakes since the 1886 event, including moderate quakes near Charleston and Summerville. The USGS National Seismic Hazard Map shows a moderate hazard for the Lowcountry, which means that while a major earthquake is not imminent, it is a realistic possibility that homeowners should consider.

How It Affects Homes

Earthquake damage to homes in South Carolina can range from minor cracks to structural failure. Common issues include:

• Foundation damage: Cracks in foundations, slabs, and walls, especially in older homes not bolted to their foundations.
• Structural shifting: Houses may shift off their foundations, leading to misaligned doors and windows, and in severe cases, partial collapse.
• Chimney collapse: Unreinforced brick chimneys are particularly vulnerable and can fall during shaking, posing a safety risk.
• Interior damage: Broken windows, fallen shelves, toppled furniture, and damaged plumbing or gas lines.

Standard homeowners insurance policies typically do not cover earthquake damage. You may need to purchase a separate earthquake endorsement or policy. In South Carolina, some insurers offer earthquake coverage, and the state’s insurance department can provide guidance. Earthquake policies often have a separate deductible, usually expressed as a percentage of your home’s insured value. After a major earthquake, federal assistance may be available through FEMA, but it usually does not cover all losses and is not a substitute for insurance. For more information on insurance, visit Ready.gov.

Older homes, particularly those built before modern building codes, are at greater risk. Unreinforced masonry, cripple walls, and homes with soft stories (like those with garages underneath living space) are more susceptible to earthquake damage. Retrofitting can significantly reduce this risk.

How to Prepare Your Home

Mitigation can reduce damage and keep your family safe. Consider these steps:

1. Secure heavy furniture and appliances: Anchor bookcases, water heaters, and televisions to walls. Use flexible connectors for gas appliances and strap water heaters to wall studs.
2. Retrofit your foundation: If your home is not bolted to its foundation, consider having it done. Brace cripple walls with plywood or oriented strand board. This is one of the most effective ways to reduce earthquake damage.
3. Reinforce chimneys: Have a professional evaluate and reinforce masonry chimneys. Replace damaged bricks and consider installing a chimney brace.
4. Install latches on cabinets: Prevent items from falling out during shaking. Use childproof latches or magnetic catches.
5. Know how to shut off gas: Learn where your gas meter is and how to turn it off. Only do so if you smell gas or see damage. Keep a wrench near the meter.
6. Create an emergency kit: Include water, non-perishable food, a flashlight, batteries, a first-aid kit, medications, and copies of important documents.
7. Practice Drop, Cover, and Hold On: During an earthquake, drop to the ground, take cover under a sturdy desk or table, and hold on until shaking stops. This is the recommended action by Ready.gov.
8. Consider earthquake insurance: Evaluate your risk and discuss coverage with your insurer. Understand the deductible and what is covered.
9. Create a family emergency plan: Decide how you will communicate and where you will meet if separated. Practice your plan regularly.

SCEMD provides additional preparedness tips at scemd.org. You can also find guidance from FEMA Earthquake Safety.

Frequently Asked Questions

Is South Carolina at risk for earthquakes?

Yes. South Carolina has a moderate earthquake risk, with the highest risk in the coastal Lowcountry. The 1886 Charleston earthquake was one of the most powerful in U.S. history, and smaller earthquakes occur regularly. The USGS monitors seismic activity in the region and provides updates on its website.

What should I do during an earthquake?

Drop, Cover, and Hold On. If indoors, stay there and get under sturdy furniture. If outdoors, move away from buildings and power lines. If driving, pull over safely and stay in your vehicle. Avoid doorways, which offer little protection in modern homes. After shaking stops, check for injuries and damage, and be prepared for aftershocks.

Does homeowners insurance cover earthquake damage?

Usually not. Standard homeowners policies exclude earthquakes. You may need to purchase a separate earthquake policy or endorsement. Check with your insurance agent and review the South Carolina Department of Insurance for guidance. FEMA assistance may be available after a presidentially declared disaster, but it is not a substitute for insurance and often covers only basic needs.

Official Resources

• South Carolina Emergency Management Division
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety