Wednesday, August 24, 2011

The East Coast Earthquake

     Yesterday we had a reminder that the Eastern United States is not seismically quiet.  An earthquake occurred in Central Virgina that was the largest one there in at least a century.  Just like the New Madrid earthquakes they were felt at a vast distance up and down the East Coast and to the West of the Appalachian mountains.  Building damage was sporadic with older buildings and chiminies suffering the most.  To give you a sense of perspective here is an account of how the New Madrid earthquake of December 16, 1811 was felt in some locations in Virginia
At Norfolk Virginia:
"Norfolk, Dec. 16.-- This morning two distinct shocks of an Earthquake were felt in this place; The first (and according to most accounts) the most violent, was about 3 o'clock. It was so severe as to awaken a number of persons out of their sleep. The shock at two very short intervals might have continued about a minute. The shaking of the beds is described, as if a strong man had taken hold on the posts, and shook them with all the violence in his power. Several clocks were stopped. The houses were shaken with great violence. Again about 8 o'clock another shock was felt by a greater number of persons, as many had risen, this was also very violent. The most sensible effect produced by this, that we have yet learned, was that of throwing a pipe of Wine off the skids, in a warehouse in Commerce-street. Before our next we expect to obtain some further particulars respecting this (in our climate) unusual convulsion of nature.
     Another location where the the earthquakes were felt was Washington, D. C, there the quake was noticed by some individuals at the growing capital of the new nation.  Here is an account for the February 7, 1812 earthquake:
"And suddenly there was a great Earthquake, so that, the foundations, &c. were shaken." Yesterday morning about 4 o'clock, another smart shock of an earthquake was felt in this city. Several persons of whom we have heard, were awaked from their sleep and much alarmed by it; in one instance a part of the ceiling of a room was shaken down by it.-From the hour at which it occurred, it was not felt by many, and its duration, &c. differently described.  "

You will notice that these report were for earthquakes with epicenters in the Central United States.  These earthquakes were of a greater magnitude than the one in Virginia yesterday but still effects of them were noted on the East Coast of the United States.  The quake of yesterday is a reminder that preparedness for earthquakes and the study of the phenomena should not be neglected in the Central and Eastern United States.