CTVNews.ca Staff
Published Sunday, Oct. 28, 2012 8:15AM EDT
Last Updated Sunday, Oct. 28, 2012 9:48PM EDT
Published Sunday, Oct. 28, 2012 8:15AM EDT
Last Updated Sunday, Oct. 28, 2012 9:48PM EDT
Aftershocks continue to hit B.C. coast after 7.7 quake
Hundreds of aftershocks hit British Columbia including a 6.4-magnitude tremor Sunday afternoon,following one of the strongest earthquakes to the area in decades.
The province’s coastline was walloped with a 7.7-magnitude earthquake just after 8 p.m. PT Saturday. The U.S. Geological Survey said the earthquake struck at a depth of 17 kilometres centred 139 km south of Masset in the Haida Gwaii region.
Residents inVancouver’s mainland felt the intense quake with smaller tremors reaching the Greater Vancouver Area. Peopleas far as Edmonton, Alberta also reportedly feelingaftershocks well into Sunday. Tremors are expected to continue for days but many will go unnoticed.
The quake prompted a number of tsunami warnings along the province’s coastand as far away as Hawaii and California, but all were called off Sunday.
Still no reports of injuries or significant damages have been reported aside from personal belongings broken and misplaced from the tremors.
Tsunami warnings were issued for a large stretch of the North and Central coast, as well as the Haida Gwaii region. These Tsunami warnings prompted some residents to evacuate their homes. Haida Gwaii and other coastal communities such as Tofino sought out higher ground.
All of the warnings affecting British Columbia’s coastline were called off at about 3:22 a.m. Sunday in a bulletin from the U.S. National Weather Service’s West Coast/Alaska Tsunami Warning Center.
Though the threat of a damaging tsunami has passed, strong waves off the coast of B.C. still pose a risk to boaters and swimmers, oceanographer Tad Murty told CTV News Channel Sunday.
“Even if the tsunami amplitude is small, the currents could be very strong,” he said.
The largest wave that lashed against Langara Island, in the Haida Gwaii area, measured 69 centimetres.
The earthquake produced strong waves that travelled north to the Alaska panhandle and south towards California and the Hawaiian islands, CTV Meteorologist Michael Kuss reported Sunday.
Environment Canada had urged residents in low-lying areas of coastal B.C. to seek higher ground as tall waves lashed the province’s shoreline. CTV British Columbia’s Penny Daflos reported that at least three communities -- Sandspit, Bella Bella and Prince Rupert -- were evacuated as a precaution.
Power outages were reported at some B.C. homes, while others said the tremor rattled their nerves and caused objects to fly off shelves.
Carsten Ginsburg, who lives in the small community of Bella Coola southeast of Prince Rupert, said the quake lasted for about 40 seconds.
"It shook everything. The electricity went out, the power lines were swinging all over the place and stuff was falling off the shelves,” she told The Canadian Press on Sunday.
In a conference call recorded late Saturday night, B.C. Justice Minister Shirley Bond told reporters the province was “certainly grateful at this point” that there appeared to be little damage.
Concerns that information was not passed quickly enough by the B.C. government to local officials has been raised. Bond told the Canadian Press she was pleased with the response but a formal review will be conducted.
“Obviously minutes and hours matter when there is a potential catastrophic event, so what I want to do is refine the process so that we do that as well as we possibly can,” Bond told the Canadian Press.
Tsunami advisories were also cancelled in Oregon, Alaska and northern California on Sunday. Under an advisory, strong waves and significant sea level fluctuations are expected but evacuations aren’t necessary.
Saturday’s earthquake was the strongest to hit Canada since 1958, when a 7.9-magnitude quake struck near the British Columbia-Alaska border, according to Natural Resources Canada.
Just nine years before then, an 8.1-magnitude quake hit west of the Queen Charlotte Islands, in the same area that the most recent quake took place.
Earlier this month, more than 590,000 people participated in an earthquake preparation drill called The Great British Columbia ShakeOut. Participants were taught to “drop, cover and hold on” in case of a tremor.
Following the quake, speculation rose regarding the idea of when the “big one” would happen – an earthquake that only happens every 500 years but would cause extensive damage in B.C. and Northwestern U.S.
The last one occurred in January 1700, when a 9.0-magnitude earthquake struck offshore of Vancouver Island.
According to Brent Ward, an earth scientist at Simon Fraser University, the “big one” would occur on a different fault line. It is expected to fall on the edge of the Juan de Fuca plate west of Vancouver Island. When that plate finally gives way Ward warns the results will be catastrophic.
Ward said the focus right now should be on the smaller quakes as they are likely to strike more frequently.
-With files from The Canadian Press
Read more: http://www.ctvnews.ca/canada/aftershocks-continue-to-hit-b-c-coast-after-7-7-quake-1.1013869#ixzz2AeVp16C9
Hawaii tsunami warning canceled after lower than expected waves
HONOLULU |
(Reuters) - Hawaii state officials on Sunday canceled a tsunami advisory prompted by a powerful earthquake off the Canadian coast that sent thousands of people fleeing to higher ground, but did not cause major damage.
The advisory was canceled shortly before 4 a.m. local time (1400 GMT) after the anticipated waves rolled in lower than expected, according to the Pacific Tsunami Warning Center.
Kevin Richards, earthquake and tsunami manager for Hawaii State Civil Defense, said water, gas and power lines were not damaged by the smaller-than-expected waves.
"Everything is normal," Richards said. "We're in good shape with this one."
Tens of thousands of people fled shoreline areas on Saturday night following siren blasts and a tsunami warning from the center that waves as tall as 6 feet could hit in some places.
Scientists downgraded the warning to an advisory shortly after 1 a.m. Sunday (1100 GMT) and there were no reports of injuries, serious flooding or damage.
The highest wave measured 2.5 feet, and that hit Kahului harbor on the island of Maui, said Dr. Gerard Fryer, senior geophysicist at the Pacific Tsunami Warning Center.
All beaches were reopened on Oahu, the most populated island in Hawaii, on Sunday morning, Richards said. Beaches remained closed on the island of Hawaii, but were set to reopen shortly.
Tsunami warning sirens began blaring across the islands at about 8 p.m. on Saturday as state officials ordered a coastal evacuation, prompting a mass exodus that clogged roadways as motorists fled low-lying areas.
On Oahu, the sirens prompted an immediate crush of traffic in Honolulu, with many motorists stopping at service stations to top up with gasoline.
Vindell Hsu, a geophysicist at the tsunami warning center, said the evacuation affected an estimated 100,000 to 150,000 people who live in Hawaii's coastal zones.
But residents and visitors resumed their daily lives around the state on Sunday. One woman, vacationing at a beachfront home in Kailua, Oahu, said this is the second time she has been evacuated from a tsunami warning.
"I do not think the state over-reacted at all," said Heidi Wilson, a San Diego resident. "I was blown away at the coordinated effort on all the islands. I felt secure with all the precautions."
The warnings followed a magnitude 7.7 earthquake that hit off Canada's Pacific coastal province of British Columbia late on Saturday.
The U.S. Geological Survey said the quake was centered 123 miles south-southwest of Prince Rupert at a depth of 6.2 miles.
The Earthquakes Canada agency said the temblor was followed by numerous aftershocks as large as magnitude 4.6 and that a small tsunami had been recorded by a deep-ocean pressure sensor.
The last time Oahu had a tsunami warning was after the devastating Japanese earthquake of March 2011.
Fryer said scientists overestimated the wave sizes in part because deep ocean sensors had a bad angle on the tsunami. The Pacific Tsunami Warning Center plans to carefully review the event.
"We have to see what worked and what didn't work ... and find ways to reduce unnecessary evacuations and still not miss anything," Fryer said.
(Additional reporting by Jolyn Rosa in Honolulu; Writing by Alex Dobuzinskis; Editing by Dan Whitcomb and Stacey Joyce)
..................end update......................................................................
Hawaii is bracing for Tsunami...
M7.7 - 139km S of Masset, Canada2012-10-28 03:04:10 UTC
Summary
Location and Magnitude contributed by: USGS, NEIC, Golden, Colorado (and predecessors)
General
Event Time
- 2012-10-28 03:04:10 UTC
- 2012-10-27 20:04:10 UTC-07:00 at epicenter
- 2012-10-27 21:04:10 UTC-06:00 system time
Location
52.769°N 131.927°W depth=17.5km (10.9mi)
Nearby Cities
- 139km (86mi) S of Masset, Canada
- 202km (126mi) SSW of Prince Rupert, Canada
- 293km (182mi) SW of Terrace, Canada
- 556km (345mi) NW of Campbell River, Canada
- 635km (395mi) SSE of Juneau, Alaska
Tectonic Summary
The October 28th, 2012 (October 27 at the location of the epicenter) M 7.7 earthquake south of Masset, Canada, occurred as a result of oblique-thrust faulting near the plate boundary between the Pacific and North America plates. At the location of this event, the Pacific plate moves approximately north-northwest with respect to the North America plate at a rate of approximately 50 mm/yr.
This earthquake is likely associated with relative motion across the Queen Charlotte fault system offshore of British Columbia, Canada. Studies of tectonics in this region suggest plate motions are taken up by strike slip faulting parallel to the plate boundary, accompanied by lesser amounts of thrust motion to accommodate the oblique nature of the plate motion vector between the two plates with respect to the orientation of the main plate boundary fault structure. This oblique component of plate motion may involve either underthrusting of the western edge of the Pacific Plate beneath North America, or be taken up on crustal faults within the North America plate. The October 28th earthquake is consistent with either scenario.
This region of the Pacific:North America plate boundary has hosted 7 earthquakes of magnitude 6 or greater over the past 40 years – the largest of which was a M 6.6 earthquake in 2009, 80 km to the south east of the 2012 earthquake. In 1949, a M 8.1 earthquake occurred closer to the Pacific:North America plate boundary, likely as a result of strike-slip faulting, approximately 100 km northwest of the October 28th earthquake, near the northern extent of Haida Gwaii region (formerly Queen Charlotte Islands).
This earthquake is likely associated with relative motion across the Queen Charlotte fault system offshore of British Columbia, Canada. Studies of tectonics in this region suggest plate motions are taken up by strike slip faulting parallel to the plate boundary, accompanied by lesser amounts of thrust motion to accommodate the oblique nature of the plate motion vector between the two plates with respect to the orientation of the main plate boundary fault structure. This oblique component of plate motion may involve either underthrusting of the western edge of the Pacific Plate beneath North America, or be taken up on crustal faults within the North America plate. The October 28th earthquake is consistent with either scenario.
This region of the Pacific:North America plate boundary has hosted 7 earthquakes of magnitude 6 or greater over the past 40 years – the largest of which was a M 6.6 earthquake in 2009, 80 km to the south east of the 2012 earthquake. In 1949, a M 8.1 earthquake occurred closer to the Pacific:North America plate boundary, likely as a result of strike-slip faulting, approximately 100 km northwest of the October 28th earthquake, near the northern extent of Haida Gwaii region (formerly Queen Charlotte Islands).
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