The United States Geological Survey (USGS) linked 114 remote earthquakes to the magnitude 8.6 East Indian Ocean quake that occurred April 11, 2012.
USGS seismologist Fred Pollitz and colleagues published their findings Sept. 26, 2012 in "Nature."
The study focused on global seismic activity triggered by the East Indian Ocean quake, according to a USGS press release.
The scientists found that the magnitude 8.6 earthquake triggered 114 earthquakes that were a magnitude 4.5 or greater in the six days following the quake.
As a result of the findings, the team is redefining the definition of an aftershock. Currently, the term aftershock refers to earthquakes that happen after and nearby the main fault rupture. The new definition will consider aftershocks to be earthquakes of any size and location that would not have taken place had the main shock not struck.
The difference in the two definitions is that an earthquake thousands of miles away can now be called an aftershock of the first earthquake if the seismic activity of the first quake can be determined to have caused the later quake.
After studying the seismic activity after the East Indian Ocean quake, the scientists determined that large earthquakes as far away as Mexico and Japan, in the following days, were actually aftershocks.
The East Indian Ocean was the largest, by a factor of 10, strike-slip earthquake ever recorded. A strike-slip earthquake is caused by two sections of tectonic plates sliding along each other horizontally with very little vertical movement.
"No other recorded earthquake triggered as many large earthquakes elsewhere around the world as this one," said Pollitz.
Remote earthquakes in the six days preceding (top) and the six days following (bottom) the M=8.6 main shock in the East Indian Ocean on April 11, 2012. The color scale indicates seismic stress, with purple = zero and red = high. This graphic is courtesy of USGS.gov.
The weather threatens to interfere with search, rescue and cleanup operations in the wake of the major 7.8-magnitude earthquake that has killed thousands of people with the death toll mounting.
Damaging wind and hail as large as softballs have been the main threats, and will continue to be into early Monday morning.
Sunny skies and cooler conditions will be the rule this week in Chicago.
Temperatures will have their ups and downs across the Northeast this week, starting off on a cool note before milder air moves in for the middle of the week.
Bouts of heavy rain will once again visit the Southeast this week, bringing the threat of flooding and travel delays.
Dauphin Island clocked a 57 mph wind gust at the time of the boating incident, according to Mesonet.
Pryor, OK (1942)
Destructive tornado hits town squarely; 52 dead, $2 million damage.
35" of snow at Summit, 39" of snow at Red Lodge and 28.1" of snow at Lewistown.
Eastern U.S. (1990)
More record heat... Location Old Record New Record Burlington, VT 90 84/1962 Boston, MA 92 91/1962 Newark, NJ 94 90/1962 Allentown, PA 92 89/1962