On July 30, 2025, a powerful M 8.8 earthquake occurred off the eastern coast of the Kamchatka Peninsula in far eastern Russia. This region is known for major earthquakes and associated tsunamis, and many have caused extensive destruction and casualties. Fortunately, there was only moderate damage from the shaking of the 2025 earthquake, and although warnings were issued all around the Pacific Ocean, the tsunami associated with the earthquake was weaker than expected. The 2025 Kamchatka event ranks 6th largest in a list of instrumentally recorded earthquakes since 1900 and is the largest earthquake in the world since the devastating 2011 Tohoku earthquake in Japan.
All great earthquakes provide scientists with new and valuable information, along with questions about how our Earth operates. For the 2025 Kamchatka earthquake, why such a strong earthquake caused relatively minor damage is a bit of a mystery. Additionally, there are questions about the earthquake possibly triggering a volcanic eruption. In this post, I’ll summarize some interesting facts about the 2025 earthquake and other powerful earthquakes.
Most of the data I report in this post is from an excellent Volcano Café blog post by Albert Zijlstra, published August 3, 2025, here: https://www.volcanocafe.org/the-kamchatka-earthquake/ and a fascinating paper by seismologist Ross S. Stein (USGS scientist emeritus) and others, published September 9, 2025, here: https://temblor.net/earthquake-insights/huge-july-2025-kamchatka-earthquake-follows-unusually-productive-foreshock-sequence-16866/. I have also written blog posts about great earthquakes and historic tsunamis, with the links here and here. Check these out for more information!
Kamchatka Earthquakes
The Kamchatka region has endured many powerful megathrust earthquakes caused by slip on the interface between two tectonic plates. The earthquakes originate in the oceanic trench that forms the subduction zone between the heavy Pacific plate that is plunging beneath a section of the more buoyant Okhotsk plate, a part of the continental North American plate. This subduction zone stretches from Japan to the Aleutian Island chain of Alaska, and many earthquakes of >M 8.0 have occurred here during historic time. Scientists estimate the convergence rate between the two plates is between 3.0 and 3.5 in (8 to 9 cm) annually. Large earthquakes that occur under oceans frequently trigger tsunamis, as have those from the Kamchatka region. Active volcanoes, many sheathed in snow, are also common in this subduction zone region. The Krasheninnikov volcano on the Kamchatka Peninsula, which had been quiet for five centuries, erupted four days after the 2025 mainshock.
Earthquake intensity map – 2025 Kamchatka Peninsula, Russia – July 29, 2025 (USGS, Wikimedia)
The earthquake mainshock occurred at a relatively shallow depth of 25 miles (35 km) and lasted 4 minutes 30 seconds. The strongest aftershock was M 7.8 on September 18, 2025. Ten days before the mainshock, on July 20, 2025, a M 7.4 foreshock struck, part of a foreshock sequence that began in 2024 with a M 7.0 event. Although Stein and others (2025) calculated a stress transfer relationship in the region, they concluded that since the vast majority of shocks of >M 7.0 do not signify a future great shock, we cannot use this information alone for earthquake predictions. However, in the ten days before the mainshock, there were an unusually high number of aftershocks from the M 7.4 event, indicating a highly stressed subduction zone. Possibly, if scientists recognize this pattern for other earthquakes of > M 8.5, it could be useful for predictions.
The 2025 earthquake occurred near the northeastern edge of a similar 1952 M 8.8-9.0 earthquake, known as the Severo-Kurilsk earthquake. Although the two earthquakes were similar in magnitude and location, the tsunamis generated were very different. In the 1952 event, a large area in the epicentral region was destroyed when three massive waves about 50 to 60 feet (15-18 m) high hit the local area. Tsunami wave heights from the 2025 event reportedly reached up to 16 feet (5 m) in the coastal region close to the rupture. Tide gauges across the Pacific basin recorded wave heights of 5.5 ft (1.7 m) in Hawaii and 4 ft (1.2 m) in Cresent City, California. In these and other areas of the Pacific, the wave heights were similar between 1952 and 2025.
Model of maximum tsunami amplitude, M 8.8 Kamchatka, Russia, July 29, 2025 (NOAA)
We know that the amount of seafloor shift during earthquake shaking is a major control on tsunami generation. Specifically, when the leading edge of the overriding continental plate that is being dragged downward breaks free and springs upwards, the elevation of the seafloor rises and a mound of water forms above the break. If the break in the seafloor is, say, 10 or 15 feet (3 to 4.5 m), a tsunami will usually start at that height and dissipate as it crosses the ocean. Possibly, the 2025 earthquake resulted in a smaller amount of displacement than other earthquakes with similar magnitudes and at similar depths? Because that break is deep beneath ocean waves, it is difficult to know how much the seafloor actually moved—in this event and for other earthquakes that have resulted in tsunamis.
As for the Krasheninnikov volcano that began erupting shortly after the 2025 earthquake, it is one of about 25 active volcanoes in the island chain along the Kamchatka Peninsula. After the 1952 M8.8 earthquake, two nearby volcanoes erupted within a week. Possibly, the shaking resulted in decompression of the underlying magma chambers, eventually leading to an eruption. Given the number of active volcanoes on the peninsula, and the fact that many other volcanoes closer to the mainshocks experienced much stronger shaking but did not erupt, the connections are unclear. Mysteries remain.
Comparison of recent and historic earthquakes by energy release, NOAA
Other Enormous Earthquakes
For instrumentally recorded earthquakes, the 2025 Kamchatka event ranks 6th, sharing the M 8.8 with the January 1, 1906 Esmeraldas, Ecuador-Colombia and February 27, 2010 Maule, Chile earthquakes.
The largest earthquakes, in order of rank, are:
1 May 22, 1960 Valdivia, Chile M 9.4-9.6
2 March 27, 1964 Prince William Sound, Alaska M 9.2-9.3
December 26, 2004 Sumatra, Indonesia M 9.2-9.3
4 March 11, 2011 Tohoku, Japan M 9.0-9.1
5 November 4, 1952 Kamchatka, Russia M 8.8-9.0
Each of these earthquakes caused widespread damage and devastating tsunamis around the Pacific Ocean, summarized in my blog posts: Exceptional Magnitude 9 Earthquakes and Great Earthquakes – From Distraction to Disaster.
For contrast to the 2025 and 1952 Kamchatka earthquakes and the associated relatively low tsunamis, the similar magnitude 2010 Maule, Chile earthquake had average tsunami wave heights of 33 to 39 ft (10 to 12 m) along the Chilean coast and a maximum recorded tsunami wave height of 95 ft (29 m). Tsunami heights for the disastrous 2011 Tohoku and 2004 Sumatra earthquakes were as high as 133 ft (40 m) and 167 ft (51 m), respectively. Within about 4 hours of the 1964 Alaska earthquake, tsunami waves of approximately 20 ft (6 m) caused major damage and ten deaths on the northern coast of California in Crescent City.
Moving Forward
We have much to learn about the many natural hazards of our world. Since earthquakes and tsunamis can cause so much death and destruction, research into these hazards is especially useful. And as more earthquakes occur, valuable new data becomes available.
Map of earthquakes 1900-2017, including five of M9 (black dots); the black dot in the upper right corner is the location of the 1952 Kamchatka earthquake (USGS earthquake archives; Wikimedia)
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Very interesting article. Thank you1
Thanks, Deborah!
A very informative post! If I were at home (on vacation in Portugal 🇵🇹) I could send a photo of the Krasheninnikov volcano. I got visit many areas in Kamchatka in 1998 and it is one incredible place! Too bad Mr Putin doesn’t want to play nice with world.
Excellent that you visited the Kamchatka region! Thanks for the comment — and enjoy Portugal!
Thanks for writing about this quake. Triggered some head scratching starting with a completely tongue in cheek comment:
– Your graphic of comparative earthquake power includes Haiti 2010 but misses Anchorage’s 2018 M 7.1 It was a ride I would just as soon not have again.
On to the real comments –
– Familiar with Pertopavlovsk from my military days. It was (maybe still is) one of the prime Soviet Naval bases in the Pacific. Epicenter wasn’t all that far S of the bay, yet things were very quiet after the quake. Tsunami videos came from an island in the northern Kurils some 350 km S of the epicenter.
– The volcano guys have a decades- long rolling argument about whether massive quakes cause eruptions. Given that most stratovolcanoes are layered piles of lavas and ash (not unlike layered snow in avalanche country) that are pressurized to varying degrees, I suppose the only surprise is we don’t see more eruptions following massive quakes. The piles must be less pressurized and unstable than we think.
Nice piece. Good to read your work again. Cheers –
Thanks for the comment – interesting info! And yeah — I pull most of the figures in my posts from Wikimedia, and sometimes they don’t include all the info I’d like to see. The comparative earthquake figure you refer to was published in 2015, so it is a bit out of date.