An 8.2-magnitude earthquake struck off the southern coast of Alaska on Wednesday night — the largest in the U.S. in decades. It caused shaking and tsunami warnings, forcing communities to seek shelter.
Geoff Abers is chair of earth and atmospheric sciences at Cornell University and a geophysicist who uses the tools of earthquake seismology to understand the forces, material cycles, and deep structure of the Earth. Abers led a deployment of seismometers in 2018 and 2019 to study the fault zone where this earthquake occurred. He says scientists knew this region had a likelihood of a large earthquake in the coming decades, but did not know when or precisely where. Abers says:
“This earthquake is in the center of a region that a major Cornell-led field campaign studied in 2018 and 2019. The Alaska Amphibious Community Seismic Project deployed 75 sea-floor instruments and another 30 onshore for fifteen months — the first real offshore survey of the largest fault system in North America. We knew this region had a reasonable likelihood of a great earthquake in the next few decades, and the earthquake that just happened is quite consistent with expectation. Nevertheless, we did not know the timing or precise location of it, so the data will be looked at carefully for clues.
“A modest tsunami was recorded nearby, with a maximum height of about three feet at Sand Point, the closest community to the earthquake.
“Several groups of scientists, including some at Cornell, are evaluating the value of bringing instruments back to this logistically challenging region.”
