06/11/2026
Jackie Caplan-Auerbach studies “weird seismic signals that are accidentally recorded.” So, when her friends Jeffery and Christine Smith reached out to her on August 10, 2025, about an odd rising tide and surging waters in Alaska’s inside passage, she went looking for what might’ve caused it.
The Smiths had already confirmed that no earthquake had occurred to cause a tsunami, so the next likely story was a landslide in the area. Caplan-Auerbach found the nearest seismometer was far away from the Smiths, so identifying one lone wiggle that could confirm a landslide was proving difficult.
“Some slides, when they're about to fail, exhibit a slight stuttering behavior prior to failure. We call that a precursory earthquake sequence," said Caplan-Auerbach. “They're not big earthquakes. They’re tiny, tiny, tiny, little stuttering events, and it's not a hugely common signal. We've probably seen it about 15 to 20 times total. After doing some processing of the Tracy Arm data, I saw that there was a booming precursory signal. And I knew at that point that it was a landslide.”
The landslide occurred off the South Sawyer Glacier in the Tracy Arm fjord and caused a 1,520 foot tsunami wave. Tracy Arm is a popular cruise ship destination, but the fjord happened to be empty at the time of the landslide.
“Had anybody been there at that time, I think we would be telling a very different story today,” Caplan-Auerbach said. “We just got ludicrously lucky.”
Read more about Western Today: https://news.wwu.edu/wwu-professor-jackie-caplan-auerbach-co-publishes-paper-on-second-largest-tsunami-ever-recorded