Johns Hopkins University | 2020 Jun 11
Using a new technique originally designed to explore the cosmos, scientists have unveiled structures deep inside the Earth, paving the way towards a new map revealing what Earth’s interior looks like. ...Earthquakes send sound waves through the Earth. Seismograms record the echoes as
those waves travel along the core-mantle boundary, diffracting and bending around
dense rock structures. New research provides the first broad view of these structures,
revealing them to be much more widespread than previously known.
Credit: Doyeon Kim/University of Maryland
Similar to the way doctors use ultrasounds to look inside the human body, earth scientists use seismic waves to probe the Earth’s interior. However, their task is much harder: they need to wait for an earthquake to record data, and when this happens, it only provides information in a piecemeal manner; the data is restricted to a tiny region and most of the time it’s impossible to distinguish weaker echoes from noise.
The unusual team of space and earth scientists used a novel algorithm called the Sequencer that was originally developed to find interesting trends in astronomical datasets. They used it to analyze thousands of seismograms, or records of vibrations of the ground following an Earthquake, collected over the past 30 years.
“With this new way to look at the data globally, we were able to see weak signals much more clearly,” says Brice Ménard ... “We were finally able to identify the seismic echoes and use them to create a map.” ...
Scientists Detect Unexpected Widespread Structures Near Earth’s Core
University of Maryland | CMNS | 2020 Jun 11
Sequencing seismograms: A panoptic view of scattering in the core-mantle boundary region ~ Doyeon Kim et al
- Science 368(6496):1223 (12 Jun 2020) DOI: 10.1126/science.aba8972