Geophysicist Finds Way to Visualise Earth’s Tremors

The article below is found on the  October 2014 issue of Wired magazine. We thought its worth bringing up here as it is such a fascinating and worthwhile effort to study earthquakes around the world.

Geophysicist finds way to visualise Earth's tremors
Geophysicist Karin Sigloch, near Le Port, Reunion, where her research ship was anchored. Antoine Doyen

Geophysicist Karin Sigloch is using earthquake tremors to study some of the oldest geological structures on the planet. In 2012, her team deployed 57 broadband ocean-bottom seismometers in the Indian Ocean around the island of Réunion, to study how the 530,000-year-old volcano Piton de La Fournaise was formed. “The sensors capture everything,” says Sigloch, a researcher at the University of Oxford. “They hear whales and cyclones, but we need to filter them out to capture our primary interest: earthquakes.”

Sigloch, a former electrical engineer who studied at Bell Labs in Murray Hill, New Jersey, uses her knowledge of signal processing to bring a different perspective to geological problems. During her PhD, she developed algorithms that translated seismic data into 3D animations (visualizations)  for the first time. “I couldn’t understand why the visualisations of the interior of the Earth were so primitive,” says Sigloch. “When medical doctors scan brains, they see in very sophisticated 3D. We had none of that.”

In 2013, she translated seismic data into a 3D picture of the Earth’s interior, which resulted in a completely new theory of how North America was formed. “We saw a lot of new stuff in what was supposed to be the best explored region in the natural world,” says Sigloch. She suggests, for instance, that the mountain ranges in the western part of North America were created when the continent collided with island chains that existed in the Pacific Ocean 200 million years ago.

A 3D render made from water-depth soundings of the ocean floor around Mauritius. Antoine Doyen
A 3D render made from water-depth soundings of the ocean floor around Mauritius. Antoine Doyen

Next, Sigloch also wants to deploy more seismometers in the ocean floor. “It’s harder to do science looking inside our planet than looking at the skies,” she says. “Space is transparent and electromagnetic waves travel easily. To look into the interior of the Earth, we have to [harness] earthquake waves, but they are sparse. We need to look in the oceans.”

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