Hi John. It may also be glaciers that are causing the earthquakes in the New Madrid area. Take Care…Don in creepy town

The ghost of past glaciers may still rattle the American Midwest. During the last ice age, a gigantic ice sheet invaded North America, weighing down the hard upper crust of the continent for millions of years. Eventually, the glaciers melted. Freed from the heavy pressure of the ice sheet, North America slowly rose. This glacial rebound continues even today and triggers quakes in the New Madrid fault zone in Missouri, Kentucky, Arkansas and Tennessee, says Stanford geophysicist Mark Zoback.

• Glaciers Of The Past