Geology, Earthquakes & Volcanism News and Discussions

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Damage from the 1958 Alaskan Lituya Bay Tsunami Can Still Be Seen from Space
By Nathan Humphrey
June 23, 2025

Introduction:

(MSN) On December 26, 2004, the world looked on in horror as massive tsunamis engulfed the shorelines of 14 countries along the Indian Ocean, ultimately killing over 230,000 people and displacing millions more. Such massive tsunamis, some reaching towering heights of 100 feet, wreaked havoc in Southeast Asia after a brutally powerful earthquake struck off the coast of the Indonesian province of Aceh. Experts measured this earthquake at roughly 9.2 to 9.3 magnitude, making it one of the most powerful earthquakes ever recorded.

For comparison, the devastating earthquakes that rattled San Francisco in 1989 and made headlines for leveling overpasses and apartment blocks measured at roughly 6.9 magnitude. Earthquakes and the tsunamis they can create have long defined the Earth's coastlines and the vast numbers of people living along them, and have destroyed even the mightiest of civilizations.

And in 1958, an earthquake off the coast of Alaska triggered a tsunami so large that it would have easily engulfed the Empire State Building. According to the NASA Earth Observatory, the 1958 Lituya Bay tsunami's effects in Alaska, one of the largest ever recorded, are still visible from space.

On the evening of July 9, 1958, an earthquake between 7.8 and 8.3 magnitudes struck off the coast of southern Alaska, initiating the tallest recorded tsunami in human history. Scientists measured the tsunami wave at roughly 1,720 feet, meaning that if it had struck New York City, this wave would have buried the Empire State Building, a skyscraper with a fascinating history, under nearly 300 feet of water.

But given the extremely low population of this part of the world, only five people who were visiting the area perished as a result of this record-breaking natural disaster, which could have easily wiped out an entire city if it had hit elsewhere.

Read more here: https://www.msn.com/en-us/news/world/n ... a&ei=107

caltrek’s comment: I didn’t realize that earthquake generated tsunamis could be so large.

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Magnitude 7.3 Earthquake Recorded off Alaska Coast. Tsunami Warning Issued
By Greta Cross
July 16, 2025

Introduction:

(USA Today ) A 7.3 magnitude earthquake was recorded off the Alaska Peninsula on Wednesday afternoon, July 16.

The U.S. Geological Survey recorded the earthquake off Sand Point, Popof Island, which is located in the center of the Alaska Peninsula, at just after 12:30 p.m. local time.

The National Oceanic and Atmospheric Administration (NOAA) issued a tsunami warning for the majority of the Alaska Peninsula, spanning up into the southern-most part of Alaska's mainland toward Anchorage.

A major earthquake, capable of causing "serious damage," is considered having a magnitude between 7.0-7.9, according to Michigan Technological University. Only about 10-15 earthquakes of this caliber are reported each year.

Read more here: https://www.msn.com/en-us/news/us/magn ... a9&ei=69

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Machine learning uncovers 10 times more earthquakes in Yellowstone caldera

by Jeff Renaud, University of Western Ontario
https://phys.org/news/2025-07-machine-u ... ldera.html
edited by Andrew Zinin

Yellowstone, a popular tourist destination and namesake of an equally popular TV show, was the first-ever national park in the United States. And bubbling beneath it—to this day—is one of Earth's most seismically active networks of volcanic activity.

In a new study, published July 18 in the high impact journal Science Advances, Western engineering professor Bing Li and his collaborators at Universidad Industrial de Santander (Industrial University of Santander) in Colombia and the United States Geological Survey used machine learning to re-examine historical earthquake data from the Yellowstone caldera over a 15-year period. The team was able to retroactively detect and assign magnitudes to approximately 10 times more seismic events, or earthquakes, than previously recorded.

A caldera—like the one at Yellowstone Park spanning parts of Wyoming, Idaho and Montana—is a large depression or hollow formed when a volcano erupts and the magma chamber beneath it empties, leading to the collapse of the land above. This is different than a volcanic crater, which is formed by outward blasting.

The historical catalogue for the Yellowstone caldera now contains 86,276 earthquakes spanning the years 2008 to 2022, significantly improving previous understanding of volcanic and seismic systems through better data collection and systematic analyses.

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Myanmar earthquake's fault rupture exceeded seismic wave speeds, offering rare evidence of supershear
https://phys.org/news/2025-07-myanmar-e ... eeded.html
by Seismological Society of America

The first studies of the 28 March 2025 magnitude 7.8 Myanmar earthquake suggest that the southern portion of its rupture occurred at supershear velocity, reaching speeds of 5 to 6 kilometers per second.

In their paper published in The Seismic Record, seismologists Lingling Ye, Thorne Lay and Hiroo Kanamori share new details about the devastating earthquake, which caused widespread and severe damage in Myanmar and neighboring countries such as Thailand, with more than 5,000 confirmed casualties. The earthquake ruptured about 480 kilometers of the Sagaing Fault that extends north-south through the central part of the country.

The researchers analyzed seismic and satellite imagery to conclude that the rupture had a large slip of up to seven meters that extended about 85 kilometers north of the earthquake's epicenter near the city of Mandalay. The slip along the 395 kilometers of rupture to the south of the epicenter was more patchy, from 1 to 6 meters and about 2 to 3 meters near the country's capital of Nay Pyi Taw.

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Google's Ambitious Push to Use 2.5 Billion Android Phones to Detect Earthquakes
After 3 years, the results not only rival conventional, dedicated seismic detectors, but also operate in large areas that currently have no other early-warning service at all.
By Graham Templeton July 23, 2025

The ubiquitous nature of modern smartphones has mostly downsides, from a wandering mind to chronic neck pain—but there are a handful of upsides to having such advanced technology in every pocket, too. For a long time, smartphones have been used to detect traffic jams, and even (albeit less frequently) to triangulate the origin of audible gunshots. Now, results are coming in from another use for universal smartphone penetration, specifically with Android phones: earthquake detection.

Researchers at Google have spent the last several years operating a preliminary version of a global earthquake detection system, running it on a larger and larger proportion of the 3 billion-odd Android phones in the world. It now runs in 98 countries, using (and serving) around 2.5 billion devices.

https://www.extremetech.com/mobile/goog ... arthquakes

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More on that by Sky News:

https://uk.news.yahoo.com/nine-people-k ... 00350.html