Earthquakes

Reflected tsunamis and space weather

Space Weather
Sat, 02 May 2020 02:18 UTC

Ionospheric disturbances over Japan on March 11, 2011.

When the Earth trembles, even the edge of space moves. Researchers have known for decades that earthquakes and tsunamis send waves of air pressure to the very top of Earth's atmosphere. Up there, in the ionosphere, the waves scramble GPS signals and interfere with radio communications much like solar flares do. Earthquakes, it turns out, can mimic space weather.

A new paper published in the research journal Space Weather shows that earthquakes and tsunamis may, in fact, affect the ionosphere much more than previously thought.

"On 11 March 2011, a magnitude 9.0 earthquake occurred near the east coast of Honshu, Japan, unleashing a savage tsunami as well as unprecedented ripples at the space‐atmosphere interaction region," report the authors, led by Min-Yang Chou of the University Corporation for Atmospheric Research (UCAR) in Boulder, CO.

Using satellites and ground-based GPS receivers, Chou and colleagues took a close look at what happened to the ionosphere over Japan in the aftermath of the earthquake. As expected, it was disturbed. Surprisingly, though, the ionospheric disturbances didn't peter out after the initial quake and tsunami; they kept going for many more hours.

The reason: Reflected tsunamis.

Comment: Massive Japan Earthquake Altered Earth's Gravity

Shallow 6.3-magnitude earthquake jolts off Papua New Guinea coast

China.org.cn
Sat, 25 Apr 2020 12:45 UTC

An earthquake measuring 6.3 magnitude struck 132 km from the coast of Papua New Guinea (PNG) on Saturday, according to the U.S. Geological Survey (USGS).

The tremor occurred at 12:53 p.m. local time west of Panguna town on Bougainville Island.

According to the USGS, the earthquake was recorded at 6.511 degrees south latitude and 154.301 degrees east longitude at a depth of 16.9 km.

So far there have been no reports or updates from any media agencies or government bodies regarding damage and no Tsunami warning had been issued at this time.

Source: Xinhua

Magnitude 6.1 earthquake jolts Miyagi Prefecture, Japan

The Japan Times
Mon, 20 Apr 2020 00:23 UTC

© JAPAN METEOROLOGICAL AGENCY
The epicenter of the earthquake that occurred on April 20 at 5:39 a.m. is located in Miyagi Prefecture

A 6.1 magnitude earthquake, registering a 4 on the Japanese intensity scale, struck off Miyagi Prefecture early Monday, according to the Meteorological Agency, but no tsunami warning was issued.

The quake, which occurred just after 5:30 a.m., came at a depth of 50 km, the agency added.

The U.S. Geological Survey said the epicenter of the earthquake was 41.7 kilometers (26 miles) beneath the Pacific seabed, rating the risk of casualties and damage as low.

Comment: Two days ago a 6.6 magnitude earthquake struck off Japan's Ogasawara island.

Timing of Earth's biggest earthquakes follows a 'devil's staircase' pattern

Brooks Hays
UPI.com
Tue, 14 Apr 2020 17:30 UTC

© Angelo_Giordano/Pixabay
Scientists have found global earthquake sequences tend to occur in clusters -- outbursts of seismic events separated by long but irregular intervals of silence.

The timing of large, shallow earthquakes across the globe follows a mathematical pattern known as the devil's staircase, according to a new study of seismic sequences.

Previously, scientists and their models have theorized that earthquake sequences happen periodically or quasi-periodically, following cycles of growing tension and release. Researchers call it the elastic rebound model. In reality, periodic earthquake sequences are surprisingly rare.

Instead, scientists found global earthquake sequences tend to occur in clusters -- outbursts of seismic events separated by long but irregular intervals of silence.

The findings, published this week in the journal Bulletin of the Seismological Society of America, suggest large earthquakes increase the probability of subsequent seismic events.

Previous models failed to account for the interconnected nature of global fault systems. Seismic event don't occur in isolation. Each major quake alters the dynamics of other fault systems.

While the research suggests large quake sequences are "burstier" than previously thought, they remain as unpredictable as ever. The gaps between bursts are irregular, making it exceedingly difficult to anticipate the next cluster.

"Mathematically described as the devil's staircase, such temporal patterns are a fractal property of nonlinear complex systems, in which a change of any part -- e.g., rupture of a fault or fault segment -- could affect the behavior of the whole system," scientists wrote in their paper.

6.6 magnitude earthquake strikes off Japan's Ogasawara island: USGS

CGTN
Sat, 18 Apr 2020 09:00 UTC

A 6.6 magnitude earthquake struck off Japan's Ogasawara on Saturday with a depth of 458 km, the U.S. Geological Survey said.

No tsunami Warning issued yet and there are no immediate reports of damages and casualties.

No serious injuries after massive explosion at Maine paper mill: 'Nothing short of a miracle'

Mark LaFlamme and Donna M. Perry
Sun Joural
Wed, 15 Apr 2020 15:35 UTC

© Russ Dillingham/Sun Journal
In this aerial view, bent and charred metal remains after an explosion at the Jay paper mill Wednesday. The explosion shook the ground and produced a plume of black smoke that was visible for miles around.

The explosion that rocked the Androscoggin Mill on Wednesday afternoon, left many with a sickening sense of deja vu.

High in the minds of some was the blast in Farmington in September that killed a veteran firefighter and injured seven others.

But when the smoke cleared Wednesday afternoon in Jay, fire officials announced, with evident relief, that no one had been seriously injured.

"After Farmington seven months ago, we were fearing the worst," state fire marshal's office Sgt. Joel Davis said, "but by the grace of God, it turned out much different today."

The explosion, Davis said, occurred in the digester area of the mill. A mill official described the digester as a large container used to cook the chips in order to reduce them into individual fiber for the paper-making process.

Shallow earthquake of magnitude 6.0 rocks northern Honduras

India TV News
Thu, 16 Apr 2020 11:20 UTC

An earthquake of magnitude 6.0 rocked northern Honduras at approximately 13:45 pm IST. As per the United States Geological Survey (USGS), the epicenter of the quake lies 55 kilometers north of Savannah Bight, Honduras, somewhere in the Caribbean sea.

Time: 2020-04-16 08:04:37 (UTC)

Location: 16.933°N 85.710°W

Depth: 10.0 km

Strong 6.0-magnitude earthquake strikes near New Zealand - USGS

Sputnik International
Tue, 14 Apr 2020 03:07 UTC

In November 2019, New Zealand was hit by another quake, which occurred off L'Esperance Rock in the Pacific Ocean near New Zealand, the US Geological Survey (USGS) said.

The quake happened at 1:07 a.m. GMT in the Pacific Ocean, 1084 kilometres to the north-east of the town of Tauranga, which is located on the country's North Island, USGS reported.

According to the US Geological Survey, the epicentre of the quake was located at a depth of 10 km, 196 kilometres south-east of Raoul Island.

Shallow magnitude 6.1 earthquake - Mid Indian Ridge

Armand Vervaeck
Earthquake Report
Sun, 12 Apr 2020 09:36 UTC

Most important Earthquake Data:

Magnitude : 6.1

Local Time (conversion only below land) : Unknown

GMT/UTC Time : 2020-04-12 06:57:48

Depth (Hypocenter) : 10 km

5.3 magnitude earthquake strikes California-Nevada border area near Yosemite

ABC
Sat, 11 Apr 2020 15:48 UTC

A preliminary magnitude 5.3 earthquake struck Saturday morning near the California-Nevada border region, northeast of Yosemite National Park, according to the U.S. Geological Survey.

There were no immediate reports of injuries or major structural damage after the 7:36 a.m. temblor.

The quake's epicenter was located about 22 miles northwest of Benton, California, and 91 miles southeast of South Lake Tahoe, the USGS said. It was measured at a depth of six miles.

Comment: Are things heating up at Yosemite again? See: 'Long overdue' Yellowstone supervolcano eruption 'paused for now', according to naturalist