Earthquakes
S


Bizarro Earth

Cascadia tension: earthquake swarm continues off the coast of Vancouver


CBC
Wed, 02 May 2012 12:08 UTC
Experts say a "swarm" of small earthquakes off the northwest coast of Vancouver Island are part of the normal seismic activity in the area, and they could continue for several more days.

A 4.0 magnitude earthquake that struck just after midnight on Tuesday morning was the eighth small quake with a magnitude between 3.8 and 4.7 to strike the region since April 22.
Image
© USGSA swarm of earthquakes struck off Vancouver Island in recent weeks.
Pacific Geoscience Centre Seismologist Gary Rogers said the activity is focused along a 20-kilometre stretch along an area called the Raveer Delwood Fault, located about 200 kilometres offshore.

"In the very thin crust that we have out there off our west coast of Vancouver Island, it often fractures in a series of small earthquakes, usually about this size being the maximum."

Rogers said more small earthquakes are expected in the area over the next week.

"They often go on for days. There's been a lot of smaller ones, so eventually they'll wind down, but typically, what we've seen in the past is that most of these swarms last a few days to a week or so."
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Bizarro Earth

USGS: Earthquake Magnitude 6.0 - Offshore Chiapas, Mexico


US Geological Survey
Tue, 01 May 2012 20:50 UTC
Mexico Quake_010512
© USGS
Date-Time
Tuesday, May 01, 2012 at 22:43:37 UTC

Tuesday, May 01, 2012 at 05:43:37 PM at epicenter

Time of Earthquake in other Time Zones

Location:
14.466°N, 92.909°W

Depth
36.3 km (22.6 miles)

Region
OFFSHORE CHIAPAS, MEXICO

Distances
93 km (57 miles) SW of Tapachula, Chiapas, Mexico

163 km (101 miles) WSW of Quetzaltenango, Guatemala

189 km (117 miles) WSW of Huehuetenango, Guatemala

861 km (535 miles) SE of MEXICO CITY, D.F., Mexico
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Bizarro Earth

USGS: Earthquake Magnitude 5.7 - Michoacan, Mexico


US Geological Survey
Tue, 01 May 2012 12:02 UTC
Image
© USGS
Date-Time
Tuesday, May 01, 2012 at 16:38:00 UTC
Tuesday, May 01, 2012 at 11:38:00 AM at epicenter Location
18.521°N, 100.886°W

Depth
77.6 km (48.2 miles)

Region
MICHOACAN, MEXICO

Distances
7 km (4 miles) S (185°) from Huetamo, Michoacán, Mexico

33 km (21 miles) NW (312°) from Altamirano,Guerrero, Mexico

70 km (44 miles) WNW (292°) from Arcelia, Guerrero, Mexico

133 km (83 miles) S (169°) from Morelia, Michoacán, Mexico

206 km (128 miles) WSW (241°) from MEXICO CITY, D.F., Mexico
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Bizarro Earth

East and West coast of Canada hit with inexplicable earthquake swarms "Sounds like dynamite exploding."


The Extinction Protocol
Sat, 28 Apr 2012 13:37 UTC
A magnitude 4.7 earthquake struck about 200 kilometres west of Vancouver Island on Friday morning but there were no reports of it being felt by island residents. This was the largest quake in a small swarm of earthquakes off the coast of Vancouver. The quake struck around 1:36 a.m. PT, according to the Natural Resources Canada. Earthquakes of that size are common in the area and experts say they do not indicate a large earthquake is more likely. The U.S. Geological Service reported three quakes of similar magnitude in the area over the past five days, and there have been several more reported in recent months.

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Bizarro Earth

4.1 magnitude earthquake jolts Southern California


The Extinction Protocol
Sat, 28 Apr 2012 13:44 UTC
Image
© USGS
A magnitude 4.1 earthquake rattled Southern California on Saturday morning, but there were no reports of damage or injuries. The temblor struck at 8:07 a.m. near Devore, about 60 miles east of downtown Los Angeles. The quake was felt across the region, in San Bernardino County, the San Gabriel Valley and the city of Los Angeles. Residents around Devore reported a sharp jolt, though there were no reports of problems.
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Bizarro Earth

Deep 6.7 magnitude earthquake hits Tonga trench in the Pacific


The Extinction Protocol
Sat, 28 Apr 2012 13:42 UTC
Image
© USGS
A 6.7 magnitude earthquake struck the Tonga Trench at a depth of 129.4 km (80.4 miles). The earthquake was too deep to generate a tsunami. The epicenter of the undersea quake was 2266 km (1408 miles) NNE of Auckland, New Zealand. The Tonga Trench is a convergent plate boundary in the South Pacific. The trench lies at the northern end of the Kermadec-Tonga Subduction Zone, an active subduction zone where the Pacific Plate is being subducted below the Tonga Plate and the Indo-Australian Plate.
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Bizarro Earth

New Faults, and Earthquake Risks, Found in Washington

Crystal Gammon
OurAmazingPlanet
Wed, 25 Apr 2012 16:00 UTC
New Faults
© Kelsey et al./USGSThis LiDAR image (acquired in 2006 by the USGS) shows five paleoseismic study sites (red dots with block perimeters) and three Holocene faults (solid red lines) inferred from the data.
Tectonically speaking, there's a lot going on in the Pacific Northwest. From the Cascadia subduction zone, where the Juan de Fuca tectonic plate is slowly pushing its way underneath the North American plate, to the Seattle Fault, where Native American legends recorded a massive earthquake 1,100 years ago, the region has its fair share of seismic hazards.

Now add to that three more potentially dangerous faults in the Bellingham Basin, a tectonically active area along the coast of Washington, near the Canadian border.

A team of researchers has discovered active tectonic faults in this region nearly 40 miles (60 kilometers) north of any previously known faults.

"We've known for a long time that the whole Pacific Northwest region is contracting very slowly north-to-south, at the rate of a few millimeters per year," said Richard Blakely, a geologist with the U.S. Geological Survey in Menlo Park, Calif., who was part of the study.

"It doesn't sound like very much, but when you concentrate that contraction on specific faults, they can become rather dangerous."
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Bizarro Earth

Long Valley super-volcano caldera rattled by earthquake swarm


The Extinction Protocol
Thu, 26 Apr 2012 10:36 UTC
Mammoth Lakes, California - A series of 6 tremors have erupted at the Long Valley super-volcano caldera over the last 24 hours- two yesterday, and four tremors today. The tremors today were a 1.1 mag (3.2 km), a 2.5 mag (4.5 km), a 1.6 mag (4.5 km) and a 1.2 mag (2.8 km). This could be the beginning of a swarm so we'll keep monitoring events and look for updates.
Image
© ANSS
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Bizarro Earth

Nicobar Island region rattled by swarm of tremors


The Hindu
Wed, 25 Apr 2012 11:18 UTC
Image
© USGS
A tremor with moderate intensity shook parts of Andaman and Nicobar Islands on Wednesday.

No injury or casualty has been reported.

The epicentre of the tremor measuring 5.7 on the Richter Scale was between Little Andaman and Car Nicobar, said disaster management director Ashok Sharma.

The earthquake occurred at 1.12 PM and originated at a depth of 10 km, he said.

USGS data
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Bizarro Earth

Mystery boom and shaking in Georgia identified as an earthquake?

Rob Pavey
The Augusta Chronicle
Wed, 25 Apr 2012 10:40 UTC
A mysterious boom that shook portions of Appling late Monday was confirmed Tuesday as a minor earthquake, according to Columbia County authorities.

The event, which registered a 2.1 magnitude on the Richter scale, occurred at 9:26 p.m. and was located near Columbia and Appling-Harlem roads, Emergency Services Director Pam Tucker said.

The temblor was not listed on national earthquake monitors, but was confirmed by a seismologist at Savannah River Site, she said.

"This would explain the loud boom and shaking that many residents felt," she said.

Earthquakes occur periodically in the area, which lies along the fall line, where the Coastal Plains and Piedmont regions meet.

Comment: The article mentions that a 2.1 magnitude earthquake produced a 'loud boom' but it was not recorded on the USGS site. Perhaps the 'loud boom' was from a different source?

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