September 4, 2013
North America Rocked By Two Major Earthquakes And Several Small Ones
Lawrence LeBlond for redOrbit.com - Your Universe Online
What started as a few small temblors that shook up Texas residents on Monday turned into an all-out rumble as three major earthquakes rocked parts of North America and Japan into Tuesday evening.
One Texas temblor on Monday measured 4.1 magnitude, while the second measured 4.3 on the Richter scale. Neither of the quakes caused much in the way of significant damage and no injuries were reported. The USGS said both quakes occurred Monday, September 2 near the town of Timpson, Texas, a small town of about 1,200 located 150 miles southeast of Dallas.
The area, which is situated within Shelby County, has been home to eleven measurable earthquakes over the last four months. Because the region is also home to nearly 30 injection wells used to store waste water from hydraulic fracturing, anti-fracking activists have been quick to point that out as a likely source of the recent temblors.
"We know that private property is being damaged and I want to know who's going to pay for that,” Sharon Wilson with the environmental group Earthworks, said in a statement to CBS affiliate KHOU 11 News. "I'm not a scientist but it's common sense. I mean when you inject a lot of mass into the earth things have to move."
Oil industry representatives, however, have repeatedly pointed out that the Timpson area is also known for its fault lines and has been recording sizeable quakes since the 1800s, long before fracking was going on.
While it is probably too early to tell what is to blame for the east Texas quakes, be it fault lines or hydraulic fracturing, another larger earthquake that struck off the northwest coast of Vancouver Island on Tuesday is most likely due to natural occurrences in the Earth.
On Tuesday, September 3 at 1:19 p.m. PDT, a 6.1 magnitude earthquake struck, followed by at least five smaller aftershocks. Despite an immediate concern for a tsunami, the NOAA downplayed any risks of that happening.
The National Weather Service reported the quake’s epicenter at approximately 90 miles northwest of Port Alice, on Vancouver Island. The quake was initially rated 6.2 by the NOAA, but then was downgraded to 6.0 by the USGS. Shortly after, Natural Resources Canada (NRC) rated it at 6.1 magnitude.
Because the quake occurred off the coast there was no concern for injuries, said NRC seismologist Alison Bird.
"I would consider this to be a moderate earthquake. It doesn't pose any threat to people. There is no tsunami expected. We haven't even received any fault reports yet. It's far enough away from communities that it really isn't any worry," said Bird.
Residents of Bella Bella, Port Alice and Port Hardy told CBC news reporters that they did not feel the quake or any of its aftershocks, but Bird said residents should still show concern and take part in British Columbia’s earthquake drill scheduled for next month.
Johana Wagstaffe, a CBC meteorologist who has a background in seismology, noted that the BC quake and aftershocks are likely connected to the Queen Charlotte fault rather than the Cascadia subduction zone, as some might expect. Although, she maintained that this is a “complicated section of West Coast tectonics. It's possible these quakes are connected to last year's October 2012 7.8 magnitude quake as well."
The region, which is part of the Pacific Ring of Fire, is known for its seismic activity.
Also on Tuesday, a 6.5 magnitude earthquake was recorded off Alaska’s remote Aleutian Islands, where a 7.0 quake had struck just a week earlier.
The Alaska Tsunami Warning Center said there was no danger of a tsunami generating from that event, which occurred Tuesday afternoon. The quake was centered about 50 miles south-southwest of Atka, at a depth of about 24 miles, according to the USGS. No reports of damage or injury were reported in nearby towns and villages.
Scientists said dozens of aftershocks have been recorded in the region since last Friday’s big quake and Tuesday’s quake was referred to as one of those aftershocks.
"We're seeing the quakes in pretty much the same area," Rafael Abreu, a geophysicist with the USGS's National Earthquake Information Center in Golden, Colorado, told The Weather Channel. "I could definitely consider it an aftershock."
A 6.5 magnitude earthquake struck near the Izu Islands in sourthern Japan on Tuesday evening. Tremors were felt as far away as Tokyo, but no damage was reported and no tsunami was expected with that event. Also, the Japan earthquake was not associated with the British Columbia temblor or its aftershocks.
The Japanese quake’s epicenter was 250 miles below the Earth’s surface and about 360 miles south of Tokyo. Japan is known for earthquakes and accounts for nearly one-fifth of all earthquakes with magnitudes greater than 6.0 on the Richter scale. Tuesday’s 6.5 magnitude tremor was minor compared to the magnitude 9 earthquake that devastated the East Coast of Japan on March 11, 2011.
What made that quake much worse was the massive tsunami that followed, triggering the worst nuclear crisis since the Chernobyl nuclear meltdown in Russia on April 26, 1986.
Also on Tuesday evening, reports came in from the USGS of a shallow magnitude 3.3 earthquake three miles from Borrego Springs, California. That tremor occurred at 9:04 p.m. PDT at a depth of 8.1 miles. The epicenter was 26 miles from La Quinta, California, 27 miles from San Diego County Estates; 29 miles from Palm Desert; and 251 miles from Phoenix. No injuries or serious damage were associated with this event.