Seismometers May Reveal Hidden Clues Around Hawaii's Kilauea Volcano

Jul 30, 2018

The Kilauea volcano has been erupting since May, after a 6.9 eruption caused an earthquake that swallowed roads and homes and sent ash spewing 30,000 feet into the air. Researchers hope to determine the stability of the ocean floor near the erupting volcano in Hawaii, and so they've put a dozen seismometers on the ocean bottom this summer, with plans to retreive them in September. 

"That earthquake seems to have changed the behavior of the volcano," says Professor Julia Morgan of Texas' Rice University. "In particular, how it's erupting."

Scientists at the U.S. Geological Survey's Hawaiian Volcano Obervatory warn the eruptions could last months or years, according to its most recent assesment.

The agency has only land-based seismometers. Ones on the ocean floor will be able to detect more information.

Rice University researchers placed 12 seismometers -- an instrument that measures the motion of the ground -- off the southeastern shore of the Big Island in July. Using cranes, the seismometers were lowered into the water and weights took them to the ocean floor as deep as 12,000 feet. When it's time to retreive them, scientists will send a signal to the seismometer and the weight will drop off.

Morgan leads the Rice University team and was awarded a National Science Foundation RAPID grant to study the ocean floor with seismometers.

She has been studying the underwater geology in and around Kilauea for decades since she worked at the University of Hawaii. Morgan took this video while flying over Kilauea in July.

The terrain under the ocean at Kilauea is complex, made up of fault lines, slumps and lava benches prone to earthquakes and landslides. If the ocean floor collapses, it could have catastrophic results.

"What we'd like to know is what the potential of that slipping more is, what the conditions are that allow it to slip, and are their other features on the south flank that support it and prevent it from collapsing and if so, what are they like and how strong are they?" asks Morgan.

If the slump were to fail, it could cause a tsunami that would reach the West Coast. Morgan doesn't think that is imminent. It could be 20-50,000 years away.

Researchers from Western Washington University and the University of Rhode Island are also studying the ocean floor with seismometers.