A large 7.9 magnitude earthquake struck off Alaska’s Kodiak Island early Tuesday, prompting a tsunami warning for a large swath of coastal Alaska and Canada’s British Columbia that was later downgraded to an advisory as possible destructive waves failed to materialize.
The U.S. Geological Survey said the quake was recorded about at 12:31 a.m. local time about 155 miles off of Chiniak, Alaska. The Pacific Tsunami Warning Center initially said “widespread hazardous tsunami waves were possible,” but later said waves failed to show up in coastal communitites.
Buoy 46410, located northeast of the quake’s epicenter, recorded a “water displacement” of 32 feet, the National Weather Service said. The reported 32 foot wave, however, failed to materialize in coastal areas, which only saw between a one and three-foot rise.
Caltech Professor Thomas Heaton said at an afternoon briefing that “mainly fish felt this earthquake.”
“Since it was a strike slip earthquake it was primarily horizontal motion of the ocean-floor and very little chance of tsunami from this type of earthquake,” Heaton said. “Of course when the earthquake first happened semiologists had to take some time to analyze the seismograms to analyze it was a strike-slip earthquake.”
The M 7.9 occurred as the result of strike slip faulting. At it's location, the Pacific plate is converging with the North America plate.
Over the preceding century, 11 other M7+ earthquakes have occurred within 600 km of today's earthquake.https://t.co/JzzWd0ID2k
— USGS (@USGS) January 23, 2018
The initial concern from the size of the quake caused officials in coastal areas to order residents to evacuate and then wait for an “all clear” before returning to low-lying areas. The town of Kodiak has several shelters above the 100-foot mark, and…Read More