Geologists mystified by significance of new swarm of tremors rattling Iceland

April 5, 2013 – ICELAND – Approximately 70 earthquakes were picked up by the automatic sensors of the Icelandic Met Office in the Grímsey Island seismic belt in North Iceland from midnight yesterday and until the morning. The activity started with a 5.5 quake on April 2. Some of last night’s quakes were of a magnitude higher than three but none measured above four points, ruv.is reports. Yesterday, around 70 earthquakes were registered from noon and until the evening, five of which were above three in magnitude. The quakes could be felt on Grímsey but not on the mainland. Seismologists are paying close attention to the epicenter of the earthquakes at Skjálfandadjúp. So far, there are no indications that the activity is spreading to other fracture zones and the condition was stable yesterday. A level of uncertainty was declared in North Iceland following the 5.5 earthquake and the region’s residents were asked to inform themselves on how to react in case of a major earthquake. –Iceland Review

More than 800 quakes: An earthquake swarm continues to shake North Iceland, home to one of the world’s largest and most active series of volcanoes. More than 800 quakes have rattled island residents, a number that’s probably already out-of-date. About 40 to 60 earthquakes hit every hour on April 2 and 3, according to the Iceland Geology Blog. Some smaller quakes preceded the biggest event, a magnitude 5.5 shaker that struck offshore Grimsey Island on April 2. The latest swarm moved about 9 to 12 miles (15 to 20 kilometers) south of the biggest temblor, said Iceland’s Meteorological Office. Another large quake, a magnitude 4.7, struck early this morning (April 4) in this southerly spot. –Live Science