Earthquakes
S


Bizarro Earth

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

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.


Bizarro Earth

4.1 magnitude earthquake jolts Southern California

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.

Bizarro Earth

Deep 6.7 magnitude earthquake hits Tonga trench in the Pacific

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.

Bizarro Earth

New Faults, and Earthquake Risks, Found in Washington

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."

Bizarro Earth

Long Valley super-volcano caldera rattled by earthquake swarm

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

Bizarro Earth

Nicobar Island region rattled by swarm of tremors

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

Bizarro Earth

Mystery boom and shaking in Georgia identified as an earthquake?

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?


Bizarro Earth

Orange County Quake Could be First on Recently Discovered Fault

LA Quake
© USGS
The earthquake may have measured only 3.9, but it still could make history in Orange County.

Monday's temblor, centered in the southern suburb of Laguna Niguel, could be the first measured on a fault discovered only 13 years ago, which runs along the coast from Newport Beach and Costa Mesa to San Juan Capistrano -- close to the San Onofre nuclear power plant.

The little-known fault - - called the San Joaquin Hills thrust -- is similar to the fault that triggered the deadly Northridge quake 18 years ago in the San Fernando Valley.

Unlike the famous San Andreas fault, which is visible from the ground, the fracture in the Earth's crust that makes up the San Joaquin Hills thrust fault is entirely underground. Because there is no visible break in the Earth's crust at ground level, the fault is perhaps more dangerous because it's unclear exactly where the boundaries of the fault are.

Scientists weren't aware of the blind thrust faults that triggered the 6.7 Northridge quake in 1994, nor the 6.0 Whittier Narrows quake in 1987 until after the ground began shaking.

Experts said Monday's temblor should serve as a wake-up call, particularly to Orange County residents who mistakenly believe that quakes are more an L.A. problem. Scientists believe that the San Joaquin Hills thrust fault is capable of generating a magnitude 7 quake or greater.

The U.S. Geological Survey in 2003 conducted a scenario of such a quake, and found it could trigger severe shaking all along southern Orange County, including Costa Mesa, Irvine, Lake Forest, Mission Viejo, Newport Beach, Laguna Beach, Dana Point and San Juan Capistrano.

Hourglass

Strong earthquakes in the past 10 years as much as during the entire 20th century

Russian scientists announced last week alarming observations about the strong earthquakes that shook the Earth. In the first decade of the 21st century there were almost as many earthquakes measuring above 6.0 on the Richter scale as there were during the entire 20th century. 14 such cases were registered in the 2001-2011 period compared to 17 strong tremors during the 20th century, the Super 19 Minuti weekly reads.

Astrologists believe that this might have something to do with entering the Age of Aquarius. By a terrifying coincidence it was on 11 March 2011 that the Fukushima disaster happened.

Bizarro Earth

Unexplained earthquake swarm in Canada: Is the big one coming?