Earthquake News

The Pacific Northwest is being shaken by small earthquakes.

The Pacific Northwest is being shaken by small earthquakes.

The discovery of "slow" earthquakes revolutionized the area of seismic hazards just 20 years ago. Scientists are still actively searching for these cunning earthquakes today.

The most famous earthquakes in recorded history were sudden, severe, and unexpected shaking events. These and all earthquakes are caused by the tectonic plates of the Earth colliding slowly. They can cause tsunamis, damage buildings, and give people little time to flee.

The junction of the North American and Juan de Fuca tectonic plates is located off the coast of the Pacific

Northwest. The subduction zone that separates the two plates extends far beneath the shores of the United States and Canada, and earthquakes are a sporadic visitor to the area. The Nisqually earthquake, which had a magnitude of 6.8 here in 2001, was felt along the coast.

But every now and again, deep beneath the Pacific Northwest, a special form of jolt known as a "slow earthquake" happens. Similar to silent earthquake shakes, these occurrences are only picked up by sensitive ground motion detectors and do no harm. Because they play a vital role in the earthquake cycle, understanding the secrets of these slow quakes is crucial to comprehending the region's future seismic hazard.

According to Cailey Condit, a structural and metamorphic geologist at the University of Washington, "[These quakes are] like eating crunchy peanut butter."

Similar to eating a handful of peanuts, regular earthquakes are unpleasant. As you clench your teeth, the pieces break. On the other hand, tectonic plates gliding past one another would be comparable to a smooth peanut butter paste.

An intermediate event are slow earthquakes. In the silky peanut butter paste, which floats in your mouth, are bits of peanut. As you nibble on the paste, your teeth will move quietly, acting as a slip indication. The crack you hear when your teeth sink into a peanut piece is comparable to a seismic signal. A signal that resembles episodic tremor and slip is produced when the contrasting smooth and brittle textures are combined.

To identify the cause of slow earthquakes is one of Cailey's research team's objectives.

Before slow earthquakes were discovered, scientists held that there were either earthquakes or there weren't any. According to Joan Gomberg, a geophysicist with the U.S. Geological Survey, there was nothing in between.

But it's wonderful to see that slow earthquakes really exist and that they release energy similarly to ordinary earthquakes, demonstrating that there is still plenty to learn. The finding sparked interdisciplinary efforts to comprehend their importance and develop the study of earthquakes.

Scientists needed to comprehend the behavior of slow earthquakes in order to determine what caused them. Slow earthquakes don't produce shaking or harm to structures. They pose no danger. But because they move slowly,

they can remain undetected. Hyper-sensitive instrumentation, both on land and at sea, is needed to find one. They are periodic in some regions of the world, like Japan and Cascadia, allowing scientists to predict their timing and keep an eye on them.

The reasons behind slow slip events and their effects, such as whether they can cause or stop a bigger, more sudden earthquake, are still unknown. Stress accumulates along the plate boundary in subduction zones as one plate is forced beneath another. That tension is released during a conventional earthquake, as the magnitude 9.1 Tohoku earthquake, as slip takes place on that boundary or a neighboring fault.

Since stress doesn't accumulate as much during slow earthquakes, they may reduce the likelihood of a larger earthquake. The tension released during a gradual earthquake, on the other hand, can go to another area of the fault system and cause a stronger earthquake. Scientists must conduct additional research before they can pinpoint the impact these occurrences have on the likelihood of earthquakes in these areas.

We have the chance to carefully examine the mechanics underlying slow earthquakes and use this knowledge to better understand the mechanics underlying huge earthquakes because they frequently occur and contain numerous minor events, according to Condit. We can watch them as they silently shake through the Pacific Northwest as scientists work to unravel the mystery of the slow earthquakes.

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