Differences between mine subsidence and earthquake damage

October 29, 2013 | SECURA Insurance
When natural events damage your home, they aren’t always covered by insurance. In fact, three potentially destructive perils – flood, earthquake, and mine subsidence – generally are not included on a standard homeowners insurance policy, leaving you at risk for exposure. Below are some answers to frequently asked questions about earthquake and mine subsidence, which may help you decide if you should obtain special insurance for each. 

What is mine subsidence? 
Underground mining in the Midwest began hundreds of years ago, when mining was not well regulated. Throughout time, cities and towns began to expand over or near the old, abandoned mines. Problems occur when the ground moves because of a failure – like collapse – at the mine level. That movement is mine subsidence, and it can directly damage buildings. 

What is the difference between mine subsidence and earthquake damage? 
Both are geological events, but the damage looks a little different. 

Earthquake: 
Damage results from shaking caused by surface waves and differs depending on severity. Light damage usually is first visible in the structure above the basement, like cracks in plaster. Moderate damage will be in non-reinforced components, like chimneys, parapets, cornices, and ornamentation. In fact, it’s possible for an earthquake to cause this type of damage while leaving the foundation intact. But earthquake damage can be severe enough to cause whole structures to collapse. 

Mine subsidence: 
Damage from mine subsidence begins in the foundation, working its way up through a structure. It can include: 
• Cracked, broken, or damaged foundation. 
• Cracks in the basement walls, driveway, or garage floor. 
• Popping and snapping sounds as if the house is shifting. 
• Walls or floors appear unleveled or tilted. 
• Doors swing open or closed. 
• In extreme cases, water or gas lines may rupture. 

If there is no evidence of foundation damage, it probably wasn’t caused by mine subsidence. 

What’s my risk for earthquake and mine subsidence? 

This map shows the general risk for earthquakes in the United States.

Mine subsidence risk varies greatly – even by county – depending on past mining activity. A good place to look is the Abandoned Mine Lands (AMLs) Portal, which provides information from U.S. Federal environmental and land management agencies about the different types of AML sites and their associated environmental, health, and safety issues. 

Who can help me find earthquake or mine subsidence insurance? 
The best person to contact is your independent agent. He or she will help you find resources to assess your risk, and link you to the appropriate insurance for your home or business. 

Information source: Illinois Mine Subsidence Insurance Fund
 

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