We have updated the Hubbard Glacier Earthquake that happened at 11:41 am to a magnitude 7. More than 20 aftershocks over magnitude 3 have followed the mainshock so far, with the largest aftershocks ranging from M4 to M5.1.
Quite an impressive event, and thankfully, no one was harmed. And it's probably a good reminder of why ongoing work to better understand and track these events matters!
And thanks to @geophysichick.bsky.social for letting all of us know about the event!
(3) There was a seiche that lasted roughly an hour after the slide, similar to past events like the 2023 Greenland landslide and tsunami.
Here's our story about this event, likely to evolve in the upcoming days: earthquake.alaska.edu/major-landsl...
(2) We saw remarkable precursor activity starting ~18 hours before the main slide. These smaller events came from the same area, which might be one of the best examples of landslide precursors that have ever been recorded.
A day later, the confirmed location came pointing to the glacier's terminus. Three things really stand out.
(1) The seismic signal was recorded more than 1,000 km away, and even the high-frequency moveout could be tracked statewide—clear signs of a big landslide.
The location pointed to ~7 km east of South Sawyer Glacier, and we got a rather large volume estimate -- range of 30 - 290 million cubic meters. That’s bigger than anything we’ve used to build our size-estimation method, so there’s a lot of uncertainty.
It has been a busy couple of days! There was a large landslide and tsunami in SE Alaska, in Tracy Arm, Sunday morning. Luckily, no injuries or casualties were reported. This region is outside of our current landslide coverage, but we were able to get a quick location after hearing about the event. 🧵
Quite an impressive event, and thankfully, no one was harmed. And it's probably a good reminder of why we should continue researching and monitoring these kinds of emerging hazards!
(3) The slide set off a seiche that lasted around 5 hours, similar to events like the 2023 Greenland landslide & tsunami.
Here's our story about this event, likely to evolve in the upcoming days: earthquake.alaska.edu/major-landsl...
(2) We saw remarkable precursor activity starting ~18 hours before the main slide. These smaller events came from the same area, which might be one of the best examples of landslide precursors that have ever been recorded.
A day later, the confirmed location came pointing to the glacier's terminus. Three things really stand out.
(1) The seismic signal was recorded more than 1,000 km away, and even the high-frequency moveout could be tracked statewide—clear signs of a big landslide.
The location pointed to ~7 km east of South Sawyer Glacier, and we got a rather large volume estimate -- range of 30 - 290 million cubic meters. That’s bigger than anything we’ve used to build our size-estimation method, so there’s a lot of uncertainty.
⚒️ 🧪
A M8.8 earthquake just ruptured the subduction zone offshore Russia’s Kamchatka peninsula. This is one of the world’s truly huge earthquakes, and a triggered tsunami is currently traveling across the Pacific ocean.
This same fault ruptured on July 20th in a M7.4, and last August in a M7.1.
Just five months earlier, we stood at this very site with 300 others during the 2024 SSA field trip. There were no visible signs of instability. This event illustrates how suddenly these failures can occur, and why real-time, regional monitoring is crucial for coastal Alaska.
doi.org/10.1029/2025...
There’s more: the largest of the three landslides triggered a modest tsunami — a 4 cm wave recorded at a nearby tide gauge.
To our knowledge, this is the first time a landslide in this region has been detected in real time and confirmed to have generated a tsunami.
Check out our new paper in GRL! On September 20, 2024, we detected three large landslides in real time at the terminus of Surprise Glacier using seismic data.
We’ve been running a test real-time landslide detection algorithm in this region for two years, and have detected 30 landslides since then.
Barry Arm was clearly showing off today!
🧪⚒️
A M6.2 earthquake below the Sea of Marmara shook Istanbul today. While damage in this event was limited, a large earthquake on this fault system is one of the world’s most serious, and most anticipated, seismic disasters.
Learn more: earthquakeinsights.substack.com/p/m62-earthq...
Looking forward to seeing everyone!
Here’s a recent piece I was part of on Alaska’s landslide hazards and the threats they pose to coastal communities.
It also highlights something bigger: why we need more scientists working on these kinds of hazards—and why supporting that work matters.
www.smithsonianmag.com/science-natu...
