Since 2011, there has not been an earthquake of this magnitude in the world. A massive 8.8 earthquake struck the Russian Kamchatka Peninsula at 11:24 a.m. local time, immediately triggering a wave of tsunami alerts across the Pacific Rim. Among the areas where the sirens sounded was the area of Japan that was devastated in 2011 by the historic 9.1 magnitude Tohoku earthquake, which triggered the massive tsunami and subsequent nuclear disaster at Fukushima, and which occupies fourth place in the ranking of the largest earthquakes measured on Earth since the beginning of the 20th century. Only the 1960 Valdivia (Chile) earthquake, which measured 9.5, surpassed the Japanese earthquake; Anchorage (Alaska) in 1964 (9.2) and the Indonesian island of Sumatra in 2004 (9.1).
Wednesday's powerful earthquake came close to the one that triggered the tragedy in Japan 14 years ago. At 8.8, it ranks sixth on the list of the largest earthquakes in magnitude, tied with the 2010 Biobío/Maule earthquake in Chile and the 1906 earthquakes in Ecuador and Colombia, according to the U.S. Geological Survey (USGS) list of the 20 largest earthquakes in the world since 1900. The fifth earthquake in this ranking, a magnitude 9, occurred on the same Kamchatka Peninsula in 1952, causing more than 2,300 deaths.
"It was a major earthquake," summarizes María José Jurado. The researcher at the Jaume Almera Institute of Earth Sciences (CSIC) is familiar with this subduction zone, having drilled last year in the Japan Trench that gave rise to the Tohoku earthquake.
The epicenter of this 8.8 magnitude earthquake was at sea, at a depth of 20 kilometers, and about 130 kilometers from the eastern Russian coast. Therefore, although it generated tsunamis, the material damage from the quake itself has not been significant on land. The city of Petropavlovsk-Kamchatsky, with a population of 180,000, is located near the epicenter, but no fatalities have been reported so far. There have also been more than a dozen aftershocks, some exceeding magnitude 7, so populations in nearby areas remain on alert.
This very strong tremor has not surprised geologists, however. And not only because there was already a strong earthquake on July 20, measuring 7.4, which has now been identified as an early aftershock (what is known as foreshock)."It occurred more or less in the same subduction zone as the 2011 Japanese earthquake, and it is a typical earthquake, very powerful and of a very significant magnitude," says Pablo Gabriel Silva Barroso, a geologist at the University of Salamanca, who emphasizes that"this is one of the most active seismic zones in the world."
As he explained in a telephone interview, the earthquake occurred on the boundary between the Pacific plate and the Okhotsk microplate. "The Pacific plate is moving beneath the Okhotsk plate at a rate of about 9 centimeters per year, causing a displacement," said this expert from the University of Salamanca.
This area of the Kamchatka Peninsula, he notes, is periodically shaken by very strong earthquakes, even magnitude 9:"There were some in 1737, 1841, 1952, and now in 2025, which means that every 75 or 100 years there's an earthquake with a tsunami of this magnitude." Wednesday's quake occurred very close to the epicenter of the magnitude 9 quake of 1952.
Energy released
The magnitude measures the energy released by the earthquake (on a scale ranging from 1 to 10), while the intensity tells us about the destructive force (on the Mercalli seismological scale which ranges from I to XII)."The 1952 earthquake in this Russian region had a magnitude of 9 and an intensity of IX. When the earthquakes of 1737 and 1841 occurred, there were no seismographs as they are today, but it is estimated that they had magnitudes between 9 and 9.3," says Pablo Gabriel Silva.
Regarding the depth at which the epicenter of today's earthquake was located, he considers that"for a subduction zone, 20 kilometers is quite shallow, because the subduction is active up to 650 kilometers deep. That is to say, an earthquake can occur along that entire extension, and the earthquakes that generate tsunamis in these areas are shallow, less than 20 kilometers," he points out. By way of comparison, the largest earthquake we have suffered in Spain in the 20th century was the Dúrcal (Granada) earthquake in 1954. It had a magnitude of 7.8 and an intensity of IV (light), and originated at a depth of 626 kilometers.
The Japan earthquake caused a nine-meter slide to the east, and while it's still early to know the full extent of Wednesday's 8.8 magnitude temblor, initial estimates are emerging. John Townend, seismologist and professor of geophysics at Victoria University of Wellington, told the Science Media Centre (SMC),"it's likely to have involved a slide of more than 10 meters over an area of approximately 150 x 400 kilometers, although further analysis will be needed over the next 12-24 hours to confirm this."
According to this expert, the earthquake has released approximately 30 times more energy than the 7.8 magnitude Kaikura earthquake of 2016, and three times less energy than the 9.1 magnitude Tohoku earthquake ."The depth, magnitude and characteristics of the fault in today's earthquake combined to generate a tsunami that has already affected nearby coasts and Japan, and will continue to have effects throughout the Pacific for the next few hours," Townend warns.
Aftershocks are also expected to continue. According to Silva,"they will likely be felt by the population for the next three, four, or five days."
