Strange ‘boomerang’ earthquake detected under the Atlantic Ocean

On a spring afternoon in 2010, a 7.2 magnitude earthquake struck the home of Rosario García González in Baja California. Gonzalaz, an elder from the indigenous Kookapah community, later gave scientists a remarkable vision: it was a kick because of the surface breakdown caused by the earthquake. Dust racing like car racing in bush landscape

But the car, it seemed, was going the wrong way.

Earthquakes usually crack a surface traveling in the same direction, such as the tip of the tear through a piece of paper. But according to Gonzalez, the progressing earthquake brought the dust clouds back to where the Templar originated – exactly what scientists expected in the opposite direction.

The backward-racing earthquake is an eye witness to thrilled scientists. Orlando Teran, who was at the time his Ph.D. At the Ensenada Center for Scientific Research and Higher Education, the description is called “brilliant”. But what happened that day remains unconfirmed, because seismic evidence could not verify what Gonzalez saw.

Now, an international team of researchers has finally captured one of these “boomerangs” brilliantly, documenting Tembler racing in one direction and then the way it came about.

The intensity of the tremors from the earthquake is usually concentrated in the direction in which the templar is traveling. But a boomerang earthquake, or scientifically “back-propagating rupture”, Can spread intense tremors over a wide area. It remains uncertain how common boomerang earthquakes occur – and how many travel at such great speeds. But a new study published today in the journal Nature Geoscience, Behind these developments lies a major step towards engaging complex physics and understanding their potential dangers.

“Such studies help us understand how past earthquakes may break, how future earthquakes may break, and how this relates to the potential impact of faults near populated areas,” Cassie Adold, Seismology for Seismology A seismologist calls for via email.

A kick in the ground

The latest boomerang was recorded near the mid-ocean ridge in the Atlantic, where the South American and African tectonic plates slowly diverge. In spring 2016, scientists placed 39 seismometers near the ridge to collect fragments of distant lakes in an attempt to visualize the base of the tectonic plate.

Several months later, a magnitude 7.1 earthquake struck. Known as Temple Hawking Zone, seismologist Stephen Hicks of Imperial College London and the first author of the new study.

The fleet of seismometers confidently recorded the ground shaking in a series of squiggles, sounding a pair of pulses. Intrigue, Hicks and his colleagues looked closely, identifying what the earthquake’s two phases were. By examining the position of the epicenter and the energy released by each rhombing phase, the team added geologic points: the earthquake was initially eastward, but then turned westward. “It was a strange type of configuration to see,” he says.

The team was still unsure where the earthquake actually bounced back and forth. So Hicks reaches Ryu Okuwaki of Tsukuba University in Japan looking for the faint echoes of the incident captured by other seismologists around the world. In a few days, analysis of these distant scars provided an answer: the earthquake had a potentially boomerang.

Further computer modeling suggested that the earthquake might initiate a deeper subterranean eastward until it reached near the ridge toward the Middle East. There, it turned backward and went through the upper section of the fault. This second leg of the Templar accelerated at the so-called SuperShear pace. The earthquake plunged the surface at an estimated 11,000 mph speed — which rapidly ended in 18.5 minutes from New York to London. It is so fast that seismic waves pile up like mach cones that fly at supersonic speeds as airborne from pressure waves. A concentric cone of waves from a superhear earthquake can further increase the destructive power of a templar.

A wife of boomerangs

When and why these boomerang events occur, it is important to understand the number of earthquake risks. Shaking by an earthquake can concentrate near one end of the fault, the direction in which the templar is traveling, which is similar to the muting of the high pitch tones of the horn when the train is run over. “Like the Doppler effect,” says seismologist Lingseng Meng of the University of California at Los Angeles, who was not part of the study team. While this concentrate shaking is usually thought of to be in one direction, a boomerang can concentrate in two opposite regions. And if it had been a superiors, the stunning could have been worse.

But at least one big question is: how often does this happen?

A boomerang earthquake at the speed of supermahir, as the team observed in the Atlantic, may be a fairly rare breed. “To the best of my knowledge, this is the first time it has been reported,” says Yoshihiro Kaneko, a geophysicist at GNS Science in New Zealand, who was not part of the study team.

But widespread evidence of the boomerang quake continues to grow. The study of these back-tracking events has been simulated in computer models as well as laboratory experiments. “The theory says it’s there, but it’s hard to see [in the real world], Says geophysicist Louisa Brotherson, a PhD researcher at the University of Liverpool in the UK, who simulates earthquakes in the laboratory.

Earthquake 101

Earthquakes can leave behind incredible havoc, while also creating some of the planet’s most spectacular constructions. Learn about the geophysics behind earthquakes, how they are measured, and where the most powerful earthquakes are seen.

During the breakdown of the boomerang, a slow earthquake, known as a tremor, does not occur with a single blow, but progresses slowly over days or months, says the Universito Cote d’Azur in France Says seismologist Jean Paul Ampairo. He recently identified back-propagating quacks in computer simulations.

There have been indications of these events for other lakes as well. Some scientists argue that the 9.0 Tohoku earthquake that struck Japan in 2011, the most powerful in the country’s recorded history, may contain some amount of boomerang rupture, Meng notes. Kumamoto has also broken into a similar process due to the 2016 earthquake, Kanakeko says. For that event, early tremors triggered two other quakes in a cascade of events, one of which ran backwards to partially overlap the initial break.

“It may actually be more common than we think,” Kaneko says.

These boomerangs can be obscured by the usual methods used to analyze Quake, based on an assumption that a temple runs in one direction. “Naturally we’re not looking for it, we don’t expect it to exist,” Ampairo says. Yet for earthquakes, it seems, complications may be the norm rather than the exception.

As Hicks puts it: “More and more we look at earthquakes in greater detail, of course we see stranger things.”


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