In addition to the increase in overall earthquake numbers, and in addition to the increase in large quakes, we are also following this story of unexplained "earthquake swarms", most recently seen in Italy. Now we see this phenomena playing out in a new location:
Canary Islands Government Puzzled By El Hierro Earthquake Swarm
The Canary Islands Government says it has commenced an in-depth geological survey of El Hierro, the smallest of the islands, in an effort to determine the source of an earthquake swarm.
The unprecedented seismic activity commenced on 19 July. In excess of 6,000 earthquakes have been recorded up to 14 September 2011. More than two dozen tremors were recorded during Wednesday (14 Sept.) alone.
The vast majority of the tremors have been recorded in the northwest of the 278.5-square-kilometre island at El Golfo, the location of a massive landslide that created a 100-metre high tsunami almost 50,000 years ago. The earth tremors have ranged between 1 and 3 magnitude, the National Geographic Institute (IGN) reported.
The earthquake swarm, prompted the Canary Islands Government to convene the first ever meeting on 22 July of the Steering Committee and Volcanic Monitoring, reflected in the Specific Plan Protection Civil and Emergency for Volcanic Risk, given what it described “the significant increase in seismic activity”.
It remains unclear if the unprecedented seismic activity on El Hierro is a precursor to a possible future increase in earthquake or volcanic activity. However, the latest surge in recorded earthquakes and the inflation of the volcano could indicate magma rising underneath El Hierro.
The biggest fear of quakes in this region are described below:
Should The East Coast Worry About A Tsunami?
Theoretically, meteorites that strike the ocean can cause massive waves. A more likely wildcard scenario is that smaller quakes could cause underwater landslides, in turn producing tsunamis.
One major source of concern for that possibility lies in the Canary Islands, Vidale said. Experts also have their eyes on the Puerto Rico trench in the Caribbean and the Gibralter Plate Boundary, off the coast of Africa and southern Europe, said Lewis Kozlosky, a physical scientist with the National Weather Service Tsunami program in Silver Spring, Md.
Both areas are seismically active and have a high likelihood of producing tsunamis, given big enough earthquakes.
Earthquake Experts Encourage Desert Residents to Prepare