Stanford Professor Explains Quake Mystery
BCN
abc7news.com
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A Stanford University geophysicist has started to unravel a tectonic mystery -- the cause of several powerful earthquakes in New Madrid, Miss., almost a century ago that could strike the region again.
Between December 1811 and February 1812, the frontier outpost New Madrid was shaken by three quakes so powerful that church bells in Boston reportedly began to ring and the course of the Mississippi River was altered.Zoback said most scientists today agree that the earthquakes each reached at least magnitude 7.
Professor Mark Zoback presented the results of his research into the temblors today at the annual meeting of the American Association for the Advancement of Science in St. Louis.While most earthquakes are caused by movement at the juncture of rigid tectonic plates, the New Madrid quake appears to have been caused by the after-effects of a massive glacier that reached down to what is now the middle of Illinois, Zoback's research shows.
According to Zoback, as the climate warmed and the ice melted, the ground was freed of the pressure of the heavy glacier. This constant release of this pressure caused the New Madrid quakes of a century ago.
feb 20, 1006
BCN
abc7news.com
__________
A Stanford University geophysicist has started to unravel a tectonic mystery -- the cause of several powerful earthquakes in New Madrid, Miss., almost a century ago that could strike the region again.
Between December 1811 and February 1812, the frontier outpost New Madrid was shaken by three quakes so powerful that church bells in Boston reportedly began to ring and the course of the Mississippi River was altered.Zoback said most scientists today agree that the earthquakes each reached at least magnitude 7.
Professor Mark Zoback presented the results of his research into the temblors today at the annual meeting of the American Association for the Advancement of Science in St. Louis.While most earthquakes are caused by movement at the juncture of rigid tectonic plates, the New Madrid quake appears to have been caused by the after-effects of a massive glacier that reached down to what is now the middle of Illinois, Zoback's research shows.
According to Zoback, as the climate warmed and the ice melted, the ground was freed of the pressure of the heavy glacier. This constant release of this pressure caused the New Madrid quakes of a century ago.
feb 20, 1006
