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Wed, 22 Aug 2018
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Earthquakes

Seismograph

Abnormal earthquake swarm continues on French Indian Ocean island of Mayotte, locals suffering from anxiety and stress

Mayotte earthquake swarm
© BRGM
It was June 14 when officials in Mayotte opened up a psychological support services unit, designed to help residents deal with the stress of hundreds of earthquakes they've experienced as part of the ongoing seismic activity the Indian Ocean island nation has endured for weeks.

The situation has "caused concerned reactions among the population," according to the prefecture, which issues daily updates on the earthquakes.

Those updates on a seismic swarm that began May 10 are mirrored in reports from the Bureau de Recherches Géologiques et Minières (BRGM), the France-based geological agency serving the territory. And those reports keep coming, nearly two months after the shaking began.

The most recent BRGM report, issued Friday, shows another two earthquakes of magnitude 4.0 or greater, and six quakes between 3.4- and 3.6-magnitude for the previous 24 hours. While the activity seemed to have slowed in mid-June, it came roaring back last Sunday with dozens of smaller earthquakes and one that topped out at a 5.1 magnitude. There were 17 more on Monday, and 12 more on Tuesday - including another 5.0 - followed by a comparable quake on Wednesday.

Almost all of the seismic activity is in the same spot about 50 kilometers to the east of the island, with the largest 5.8-magnitude quake occurring on May 15. It also was the largest ever recorded in the archipelago, surpassing a 5.2-magnitude event in 1993 that had previously been considered the most powerful.

While there have been no reports of serious injury or fatality, the constant shaking has created anxiety and uncertainty for some of the 250,000 people living in Mayotte as well as visitors to the tourism hotspot. Some minor damage has occurred to buildings, including a school in Dembeni. At least 10 families have been evacuated from damaged homes and relocated, at least until the threat passes.

The problem is that it never does.

Comment: "The seismic activity remains abnormal and persists," according to the Bureau de Recherches Géologiques et Minières (BRGM). Could it be related to a slowdown in Earth's rotation? See also:


Seismograph

Shallow magnitude 6.1 earthquake strikes off the coast of Jalisco, Mexico

A 6.1 magnitude earthquake has struck off the coast of Mexico
© USGS
A 6.1 magnitude earthquake has struck off the coast of Mexico
An earthquake measuring 6.1 magnitude has struck the Pacific coast of Mexico, the United States Geological Survey has reported.

It hit 55 miles south-west offshore from Cihuatlan, in Jalisco state, around 4.55am BST.

The USGS estimated the depth of the tremor at around six miles.

Luis Felipe Puente, head of the country's Civil Protection agency, said on Twitter that the quake had been felt only lightly and that there were no reports of damage so far.

Seismograph

Second quake in 2 days strikes Surrey, UK - M2.4 rattles houses

surrey cricket
An earthquake has rocked Surrey for the second time this week with reports of a house shaking as if "a truck had crashed into it".

Researchers from the British Geological Survey (BGS) said the tremor, with a magnitude of 2.4, struck shortly before 7am in Newdigate near Dorking, at a depth of three miles.

The organisation said it hit in the same area as the 2.6 magnitude quake on Wednesday.

There were reports of "a loud bang and the whole house shook like a truck had crashed into it" for about two seconds, the BGS said.

Classic car parts owner Roy McNeill and his wife Judy, from nearby Beare Green, both felt the effects of the tremor.

Comment: The UK is considered relatively seismically quiet and yet it seems no where is being spared from the dramatic increase in earth movement:


Seismograph

Powerful M6.1 quake strikes Port Villa, Vanuatu - Location considered "unusual"

vanuatu wuake 6.1
A POWERFUL 6.1-magnitude earthquake has hit Vanuatu, US seismologists said, but there were no immediate reports of damage.

The quake struck at a depth of 21 kilometres some 30 kilometres west of the capital Port Vila, the US Geological Survey said.

USGS said there was low likelihood of casualties and damage although it added that recent earthquakes in the area had caused secondary hazards such as landslides.

"Definitely shaking would have been felt in the area, but we have received no reports yet of any damage," Geoscience Australia duty seismologist Hugh Glanville told AFP.

Comment: Seismic and volcanic activity around the planet appears to be increasing in recent months - just as some scientists predicted:


Seismograph

Vancouver Island hit with over 150 tremors in 24 hours

vancouver tremors
© John Cassidy and pnsn.org
More than 150 tremors have hit Vancouver Island in the last 24 hours, and seismologists are monitoring the situation to see if it turns into an Episodic Tremor and Slip event.

Vancouver Island is normally moving toward the Lower Mainland at a rate of about one centimetre per year.

"Ferry fares keep going up but the distance is actually getting a little bit shorter," jokes John Cassidy, seismologist with the Geological Survey of Canada.

But every 14 months or so there is a Tremor and Slip event - a discovery made by two local scientists Gary Rogers and Herb Dragert - when Vancouver Island slips backwards a few millimetres towards Japan. Seismic recording instruments show Victoria moving in one direction and then changing direction for about two weeks during these episodes. These events add pressure to the locked Cascadian Subduction Zone fault.

Seismograph

New research suggests risk of California earthquake higher than previously thought

Aftermath of 6.0 quake in Napa, CA
© Robert Galbraith/Reuters
Aftermath of magnitude 6.0 earthquake in Napa, California, 2014.
Geophysicists are hypothesizing that the San Andreas fault line in California could be the central point of a massive earthquake after new research suggested that the fault may be at higher risk than previously thought.

Researchers at Arizona State University have published a new study looking at the likelihood of a 7.5-magnitude (or stronger) quake occurring and rupturing the entire fault line.

It has long been thought that the central section of the fault line, which stretches 90 miles from San Juan Bautista southward to Parkfield, was creeping steadily in such a way that provided for the safe release of energy. That "creeping" movement, scientists believed, lessened the chances of a huge quake rupturing the entire fault line - but new research casts doubt over old assumptions.

Seismograph

At least 3 killed, 200+ injured after 6.1 magnitude earthquake strikes Osaka, Japan

Osaka earthquake
© Kyodo via Reuters
At least three people have been confirmed killed and more casualties are feared, after a magnitude 6.1 earthquake hit north of Osaka Prefecture in western Japan, local media report.

An 80-year-old man and a young 9yo girl were killed in Japan, crushed by collapsing walls, public broadcaster NHK reported. Several others are reported in a state of "cardiopulmonary arrest," a condition usually used by Japanese authorities until a formal examination has been conducted to confirm death.

At least 217 people were injured, mainly across the northern Osaka and neighboring prefectures, the broadcaster reports, citing data from local police and fire departments

Some 170,000 households remain without power in Osaka, as well as neighboring Hyogo prefecture, according to local electricity operator Kansai.

Attention

Volcano in the Galapagos Islands erupts after series of 9 earthquakes

A volcano on the Galapagos Islands has started erupting
© Info5Chile
A volcano on the Galapagos Islands has started erupting
Lava flows and a gas column spanning about two to three kilometers high have been a feature of the eruption.

According to the Geophysical Institute (I) of the National Polytechnic School, the Galapagos' La Cumbre volcano - located on Fernandina island - erupted Saturday.

The eruption took place between 11:00 a.m. and 11:15 a.m. (Galapagos time) and was preceded by a series of nine earthquakes ranging from 2.5-magnitude to 4.1-magnitude. La Cumbre volcano measures 1,476-meter high and occupies almost the entire island. The eruption occurred on the northeastern sector of the volcano.

Lava flows and a gas column spanning about two to three kilometers high have been a feature of the eruption. Reports are that a flow has already reached the sea.

"There are some species that could be affected, however, being a flow (of lava) that is in only one direction, on only one side of the island, the possible impacts that there would be would not have a significant impact on biodiversity," director of the Galapagos National Park (PNG), Jorge Carrion, assured.


Seismograph

Small earthquake hits western North Carolina with a 'loud boom'

North Carolina earthquake with boom
© USGS/WNCN
A small earthquake hit a county in the North Carolina mountains on Sunday evening, officials said.

The 2.6 magnitude was in Wilkes County less than a mile from the town of Hays, the U.S. Geological Survey said.

The earthquake was felt in Blowing Rock, about 40 miles away, officials said.

The quake, which hit around 8 p.m., had a depth of 4.3 kilometers.

A weather website based in the area reported on Facebook that they heard a "loud boom." Others commented on Facebook that they heard two "loud booms."

Seismograph

M4.4 earthquake shakes part of northern Oklahoma

ohklahoma quake 4.4 June 9th 2018
The U.S. Geological Survey says a 4.4 magnitude earthquake shook parts of northern Oklahoma and neighboring Kansas.

Geologists say the earthquake was recorded at 8:59 a.m. Saturday about 16 miles (26 kilometers) east of Cherokee, about 100 miles (160 kilometers) northwest of Oklahoma City. The earthquake was recorded at a depth of five miles (8 kilometers).

Comment: Fracking is likely to be a contributor to the quakes but it seems that geologic activity in general is on the rise: