Expert Interpretation: The Sea of Kamchatka is Ripped Apart by a Strong Earthquake, the Entire Pacific is Trembling!

One Picture to Understand Tsunami Warning Levels!

8.8 Magnitude Major Earthquake Occurred in the Waters Off the Coast of Kamchatka, Russia

University of Southern California Earthquake Research Center, Professor Li Yonggang

According to the United States Geological Survey (USGS), on July 29, an 8.8 magnitude earthquake occurred in the waters off the coast of Kamchatka, Russia (see Figure 1), triggering tsunami alerts along the entire west coast of the United States and prompting evacuation warnings in Hawaii. Figure 2 shows the tsunami alerts issued after the earthquake. Purple areas in the figure are severely threatened by tsunamis, red areas indicate warnings of tsunami invasion, and brown areas are under observation for tsunami development.

The USGS stated in its latest assessment that this earthquake occurred at 4:24 PM Western Time on July 29, with the epicenter located approximately 119 kilometers southeast of Petropavlovsk-Kamchatsky, Kamchatka. The earthquake had a shallow focus, with a depth of about 19.3 kilometers.

Seismic waves reached the Kamchatka Peninsula, causing ground shaking with an MMI of 7 degrees in the southeastern coastal areas (see Figure 3). This could potentially cause building collapses and casualties. The USGS estimates that there is a 44% probability that this 8.8 magnitude earthquake could result in 10-100 deaths or serious injuries on the island (see Figure 4). There are currently no reports of casualties.

Structural Overview: On July 29, 2025, an 8.7 magnitude earthquake occurred east of Petropavlovsk-Kamchatsky, Kamchatka, Russia. This earthquake was caused by shallow thrust fault activity. In the area where this earthquake occurred, the Pacific Plate moves northwestward relative to the North American Plate at a rate of approximately 77 millimeters per year. Notably, the North American Plate extends beyond the North American continent to the west. The location and direction of movement of this earthquake are consistent with the fault activity at the subduction zone interface of the Kuril-Kamchatka Arc. Although earthquakes of this scale are typically represented as points on maps, a more accurate description is the slip over a larger fault area. Thrust fault events of this magnitude are usually approximately 390 kilometers long and 140 kilometers wide. The Kuril-Kamchatka Arc region frequently experiences moderate to large earthquakes. In the past century, within a 250-kilometer radius of the 8.8 magnitude earthquake on July 29, 2025, there have been 31 earthquakes of magnitude 6.5 or higher. These include a 7.4 magnitude earthquake on July 20, 2025, which is now considered a foreshock of the 8.7 magnitude earthquake on July 29, 2025. The epicenter of the July 29, 2025 earthquake is located 45 kilometers southeast of the epicenter of the 9.0 magnitude earthquake in Kamchatka in 1952, which triggered a destructive tsunami across the Pacific.

Currently, tectonic plate movements on the western side of the Pacific Ring of Fire are very active, with frequent strong earthquakes. In comparison, the tectonic plates on the eastern side of the Pacific are relatively quiet. However, in recent days, two earthquakes of magnitude 4 or above have occurred near the coast of the border between California and Oregon, located at the southern end of the Cascadia Subduction Zone. A 9.0 magnitude earthquake occurred off the coast of Seattle in 1700 in the northern part of this subduction zone.

Original article: https://www.toutiao.com/article/1839047393599496/

Disclaimer: The article represents the views of the author.