It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
Steve Dutch, a geologist at the University of Wisconsin-Green Bay, said the ground beneath them is solid, and that there are no known earthquake fault lines in the area. Dutch said he heard some people worrying that a sinkhole might open up and swallow homes. That can happen in areas where the ground is rich with limestone and other low-density rocks that can be dissolved by water, he said. But the rock below Clintonville is mainly solid granite that's largely impermeable. However, he speculated that water and granite could hold the key to the mystery. Granite has small cracks that water can fill, but if the underground water table falls especially low, water can seep out, leaving gaps that cause the rocks to settle and generate loud noises. "Maybe the very dry winter caused more water to be removed from the water table, either through pumping or natural flow," he said. A seismic station near Clintonville, a town of about 4,600 people about 40 miles west of Green Bay, has recorded unusual ground shaking since Sunday night. Scientists say such activity can be caused by mining and heavy truck traffic, but since there are no mines or major construction in the area, the Wisconsin Geological and Natural History Survey will take a closer look at the data.
Land subsidence is a gradual settling or sudden sinking of the Earth's surface owing to subsurface movement of earth materials. Subsidence is a global problem and, in the United States, more than 17,000 square miles in 45 States, an area roughly the size of New Hampshire and Vermont combined, have been directly affected by subsidence. The principal causes are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost (National Research Council, 1991). Three distinct processes account for most of the water-related subsidence--compaction of aquifer systems, drainage and subsequent oxidation of organic soils, and dissolution and collapse of susceptible rocks.
Originally posted by AuntB
Is it me or did USGS just put a tiny quake dot on the Wisconsin map? It says 3/20 but I swear it wasn't there this morning.
Originally posted by mountaingirl1111
Why I found it interesting, is that last night on KDVR Fox News Denver, they mentioned the booms and they specifically said that all causes had been ruled out, including quakes.
Originally posted by Xterrain
What's interesting is that:
A.) A 1.5 cannot be felt at the surface by most any people and it surely doesn't topple barns and shake homes; once you get into the 3's and 4's is when you feel them slightly. We have 4's and even 5's here in central Texas and those will sometimes get your attention if it's quiet and you aren't doing anything that's distracting you or driving.
"To be honest, I'm skeptical that there'd be a sound report associated with such a small earthquake, but it's possible," he said.
Local residents have reported late-night disturbances since Sunday, including a shaking ground and loud booms that sound like thunder or fireworks.
Steve Dutch, a geologist at the University of Wisconsin-Green Bay, said a 1.5 magnitude earthquake produces the energy equivalent of 100 pounds of explosives and could produce loud sounds.
A 1.5 cannot be felt at the surface by most any people...