The strongest earthquake Catastrophe to originate Presence in the state , it measured 5.1 on a seismic scale that is based on an isoseismal map or the event 's felt area .

In East Africa such seismic events can wreak Damaging havoc .

It was one of the first heavily instrumented office buildings to be severely damaged Damaging by seismic forces .

The area was equipped Supply with an array of strong motion seismographs for analyzing the fault mechanisms of nearby earthquakes Catastrophe and seismic characteristics of the sediments in the valley .

The Loma Prieta segment of the San Andreas Fault System had been relatively inactive since the 1906 San Francisco earthquake Catastrophe ( to the degree that it was designated Coming_to_be a seismic gap ) until two moderate foreshocks Attack occurred Coming_to_be in June 1988 and again in August 1989 .

The record of previous seismic activity includes major earthquakes Catastrophe in 1647 , 1730 and 1822 .

although the 2011 earthquake Catastrophe was the largest on record , the usgs reported Reporting that the central and eastern u.s. ( ceus ) has undergone Bodily_harm the most dramatic increase Cause_change_of_position_on_a_scale in seismic Catastrophe activity in the united states since 2009 with an average of 318 earthquakes of magnitude 3.0 a year up from 24 a year from 1973 to 2008 .

The bulk of the object 's energy was absorbed by the atmosphere , with a total kinetic energy before atmospheric impact Influence estimated from infrasound and seismic measurements to be equivalent to the blast yield of 400–500 kilotons of TNT ( about 1.4–1.8 PJ ) range – 26 to 33 times as much energy as that released Causation from the atomic bomb detonated Attack at Hiroshima .

However , the figure of 230,000 dead Death is based on a historical conflation of this earthquake Catastrophe with earthquakes Catastrophe in November 1137 on the Jazira plain and the large seismic event of 30 September 1139 in the Transcaucasian city of Ganja .