Canada: Tsunami warning issued after quake
Posted on: 11:22 AM IST Oct 28, 2012
Anchorage, Alaska: The first wave from a small tsunami has been reported in a southeast Alaska community. State officials say a wave with a height of about 4 inches was measured in Craig late on Saturday evening. That was smaller than earlier forecasts, which said the wave could have been up to 1 foot. Parts of southeast Alaska and the Canadian coast remain under a tsunami warning.
The warning was sparked by a strong earthquake Saturday night that shook off the west coast of Canada. The US. Geological Survey said the 7.7-magnitude earthquake hit in the Queen Charlotte Islands area, followed by a 5.8-magnitude aftershock several minutes later.
A small tsunami prompted state and federal officials to warn people in southeast Alaska and down the Canadian coast to take precautions. The National Weather Service issued a warning for coastal areas of southeast Alaska including the small community of Craig. The US Coast Guard in Alaska said it's trying to warn everyone with a boat on the water to prepare for a potential tsunami.
The first wave was expected to Craig about 9:10 pm local time, but it wasn't expected to be large, about 1-foot. "That's the predicted arrival time for the first wave, which typically is not the largest but nevertheless we don't expect the maximum wave height to be large," said Bill Knight at the West Coast and Alaska Tsunami Warning Center.
He said any forecast that includes waves of 1-foot to 3 1/2-feet qualifies for an advisory threat level, which does not mean a full-fledged evacuation. "It does mean pulling back from harbors, marinas, getting off the beach," Knight said. The state Department of Homeland Security and Emergency Management activated its emergency operations center and notified officials in southeast Alaska communities.
"We are instructing residents to be alert for messages from their local emergency officials," spokesman Jeremy Zidek said in an email to The Associated Press. Lt Bernard Auth of the Juneau Command Center said the Coast Guard was also working with local authorities to alert people in coastal towns to take precautions. Lucy Jones, a USGS seismologist, said the earthquake likely would not generate a large tsunami.
"This isn't that big of an earthquake on tsunami scales," she said. "The really big tsunamis are usually up in the high 8s and 9s." She said the earthquake occurred along a "fairly long" fault - "a plate 200 kilometers long" in a subduction zone, where one plate slips underneath another. Such quakes lift the sea floor and tend to cause tsunamis, she said.