New Technology That Detects Earthquakes by "Scent"

According to the Science and Technology Service of Saed News, quoting ISNA, a new technology developed by researchers at the California Institute of Technology (Caltech) can delve deep into the secrets of tectonic plates and detect earthquakes by "scent."

Researchers at Caltech can now send pulses of light deep into the Earth to detect even the smallest vibrations.

Beneath our feet, deep within the Earth, a mysterious boundary of brittle crust separates the Earth's crust from its mantle. Known as the Mohorovičić discontinuity or Moho, this boundary has long fascinated scientists.

A new method has now provided fresh insights into this hidden boundary, leading Caltech researchers to introduce a new seismic technology called Distributed Acoustic Sensing (DAS).

Using DAS, researchers explore the Moho by analyzing reflected seismic waves. By sending pulses of light deep into the Earth through a cable, they can detect even the smallest vibrations.

"The Moho is a really interesting boundary for seismologists because it tells us what is happening inside and between the tectonic plates at depth," said James Atterholt, a postdoctoral researcher at the United States Geological Survey.

Studying the Moho Structure

The Moho lies at a depth of 12 to 43 miles beneath continents.

Traditional methods of imaging the Moho either have low resolution or are very expensive. Now, this DAS method turns fiber optic cables into seismometers.

During an earthquake, seismic waves are emitted, some of which reflect off the Moho.

Laser pulses sent through these cables can provide data on ground vibrations caused by earthquakes or other disturbances, allowing researchers to study the subsurface.

Interestingly, they originally developed this method to analyze reflected laser light along the entire length of the fiber optic cable. This approach allows them to understand the Earth's internal movements, making the cable act like a network of many small seismometers.

Distributed Acoustic Sensing (DAS) enables researchers to map the Moho's structure with high resolution over large areas, providing precise insights into this critical geological boundary.

"This method can tell us whether major faults penetrate into the mantle, how ancient and contemporary processes have left their marks on continents, and how strong the deep crust is in specific locations," Atterholt explained in a press release.

New Insights into the Moho

The team used Distributed Acoustic Sensing (DAS) to gain new insights into the Moho, using a fiber optic cable in the Mojave Desert to study earthquakes and map the Moho over two years.

They discovered that the Garlock Fault extends deeper into the mantle than previously thought in this area. The Garlock Fault is a major player in Southern California's seismic activity.

However, the data shows that the Moho is significantly tilted beneath the Coso Volcanic Field, a dormant volcanic area in northern Mojave.

This research illuminated the connection between the mantle heat source and the magma chamber in the Coso Volcanic Field, highlighting the geothermal potential of this area.

"Everything happens deep within the lithosphere, which includes the Earth's outermost part, including the crust and upper mantle, and what you can do with DAS is only limited by your creativity," Atterholt said.

This study was published in the journal Science Advances.