September 3, 2011 by cd
Alaska has been shaken by a 6.8 magnitude Earthquake in the Pacific Ocean early Friday morning at around 6:55 a.m. EDT (1055 GMT) which prompted a brief tsunami warning for Alaska’s Aleutian Islands and the coastal areas in Alaska.
However after an hour, the warning was canceled after only a small wave was recorded in the community of Atka in the Western part of Alaska.
Alaska Department of Homeland Security spokeperson Jeremy Zidek said a little bump of wave was seen in Atka and nothing of any destructive power. There were no initial reports of casualties, damage or injuries according to the United States Geological Survey (USGS).
Residents were evacuating to higher ground in Atka but then stopped at the cancellation of the Tsunami warning, Zidek said.
The preliminary measurement of the Alaska Earthquake on Friday was 7.1 but the USGS later put the official size at 6.8.
According to US Geological Survey, the earth’s most active seismic feature, the circum-Pacific seismic belt, brushes Alaska and the Aleutian Islands, where more earthquakes occur than in the other 49 States combined. More than 80 percent of the planet’s tremors occur in the circum-Pacific belt, and about six percent of the large, shallow earthquakes are in the Alaska area, where as many as 4,000 earthquake at various depths are detected in a year.
The largest magnitude earthquake in the central interior of Alaska since October 1947 occurred on October 29, 1968. Rated magnitude 6.5, the shock centered southeast of the village of Rampart, on the Yukon River. This area was badly shaken, but no damage was sustained, since most buildings at Rampart were of log construction. Most residents were frightened from buildings, goods toppled from shelves, and equipment not bolted down shifted. Greatest evidence of the shaking was in the Hunter Creek area near Rampart. Many landslides occurred, most on south-facing slopes. Lake ice cracks were extensive in some areas and were observed some 50 miles from the epicenter in the Minto Lakes area. Ground cracks were noted at Nenana, about 50 miles southeast of Rampart, and plaster cracked and fell. During the first 24 hours after the earthquake, College Observatory recorded over 2,000 aftershocks.
Image courtesy of Irish Weather Online