sinkholes -Louisiana Sinkhole
March 5, 2013 in Outdoors
What Can Trigger a Sinkhole?
Sinkholes can form from a variety of causes including natural and man-made activities and include ground collapse related to:
Naturally dissolved voids in rock
A drop in the water table from drought or pumping of nearby wells
Heavy construction or weight at the ground surface
Collapse of underground mines
|Tectonic SettingThe NMSZ coincides with an ancient rift complex that formed during the late Precambrian and was reactivated during the Mesozoic (~160 million years ago) when the supercontinent Pangaea was breaking apart to form theAtlantic Oceanand the separate continents we now have. During that time, scientists believe that a mantle plume (an upwelling of hot magma similar to that beneathHawaii) developed under the New Madrid. The upward push and the extensional pull thinned the crust and allowed magma to push its way up through faults, forming igneous plutons. As North America drifted past the hot spot, the New Madrid crust began to cool and sink, warping downward. Today, the region is undergoing compressional stress which is further allowing movement along the faults (left).|
|The NMSZ is comprised of multiple fault segments. Seven faults have been identified: four buried faults interpreted from seismicity, and three visible at the surface. The New Madrid region has more earthquakes than any other part of the U.S.East of the Rocky Mountains– 100 to 200 quakes detected per year. Data recorded from these earthquakes is used to learn more about the structure and faults underground. To learn more about how the subsurface faults were identified, watch the video below (or click here).|
We’re now looking at the stability of 7 salt caverns by giant sinkhole — We used to be mainly worried about just one — “A lot of things going on”
We started off back in September everybody was mainly worried about the Oxy 3 cavern.
Because of a lot of things going on, we’ve expanded the scope; we’re now looking at all the caverns shown here.
We’re looking at Oxy 3 obviously, Oxy 1, 2, 9, 10; Crosstex 2 and 1.