Strong M6.8 aftershock hits east of Severo-Kurilsk, near Kamchatka Peninsula
A strong earthquake registered by the USGS as M6.8 struck east of the Kamchatka Peninsula, Russia, at 05:37 UTC on August 3, 2025. The agency reports a depth of 35 km (22 miles), while the EMSC lists the same magnitude at a depth of 25 km (16 miles). This event is part of the ongoing aftershock sequence following the tsunami-generating M8.8 earthquake that occurred at 23:24 UTC on July 29.
Epicenter of M6.8 earthquake near Kamchatka, Russia on August 3, 2025. Credit: TW/SAM, Google
The epicenter was located 118 km (73 miles) E of Severo-Kuril’sk (population 2 422), 265 km (164 miles) S of Vilyuchinsk (population 25 204), and 281 km (175 miles) SSW of Petropavlovsk-Kamchatsky (population 181 216), Kamchatka.
5 000 people are estimated to have felt light shaking.
Based on all available data, there is no tsunami threat from this earthquake, NWS PTWC said.
The USGS issued a Green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.
Overall, the population in this region resides in structures that are resistant to earthquake shaking, though vulnerable structures exist. The predominant vulnerable building types are adobe block and unreinforced brick with mud construction.
This earthquake is part of a strong aftershock sequence following the M8.8 megathrust earthquake that struck off the Kamchatka Peninsula at 23:24 UTC on July 29, 2025. Since that mainshock, multiple significant aftershocks (M6+) have been recorded across the region, particularly east and southeast of Severo-Kuril’sk and south of Vilyuchinsk.
A M6.4 earthquake at a depth of 10 km (6.2 miles) struck 143 km (89 miles) east-southeast of Severo-Kuril’sk at 14:47 UTC on July 30, followed closely by a M6.9 event at 25.3 km (15.7 miles) depth, located 133 km (83 miles) southeast of Petropavlovsk-Kamchatsky at 00:09 UTC on July 30.
Minutes later, at 00:16 UTC, a M6.2 quake occurred 131 km (81 miles) southeast of Vilyuchinsk at a depth of 35 km (22 miles). Another M6.0 earthquake hit 159 km (99 miles) south-southeast of Vilyuchinsk at 23:37 UTC the same day, also at a depth of 35 km (22 miles).
On July 31 at 05:27 UTC, a M6.2 earthquake struck 220 km (137 miles) southeast of Severo-Kuril’sk at a depth of 10 km (6.2 miles), followed by a M6.1 at 18:20 UTC on August 1, located 219 km (136 miles) east-southeast of Severo-Kuril’sk, also at 10 km (6.2 miles) depth.
Activity continued into August, with a M6.0 quake recorded 166 km (103 miles) south-southeast of Vilyuchinsk at 14:14 UTC on August 2 at a depth of 20.5 km (12.7 miles).
The most recent and strongest aftershock so far was today’s M6.8 at 05:37 UTC.
The July 29 M8.8 megathrust earthquake generated a trans-Pacific tsunami. The rupture occurred along the Kuril-Kamchatka subduction zone at a shallow depth of 35 km (22 miles), displacing the seafloor across an area estimated at roughly 390 x 140 km (240 x 87 miles). This displacement produced tsunami waves that propagated across the Pacific Ocean, triggering warnings in more than a dozen countries.
In Russia’s Far East, the tsunami reached the town of Severo-Kurilsk with wave heights estimated between 3 and 5 m (10 to 16 feet). The waves inundated coastal infrastructure, damaging port facilities, fish-processing plants, and a kindergarten.
Several boats were swept inland or damaged at dock, and parts of the shoreline were submerged by the initial wave and subsequent surges. Local authorities reported injuries but no fatalities.
Elsewhere around the Pacific Rim, wave heights were considerably lower. In Hawaii, tsunami waves reached a maximum of 1.7 m (5.6 feet) at Kahului on Maui, 1.5 m (4.9 feet) at Hilo, and 1.2 m (4 feet) at Haleiwa on Oahu. Temporary evacuations were issued for low-lying coastal areas, but no major damage was reported.
In California, waves up to 1.1 m (3.6 feet) were recorded along the northern coast, including Crescent City, Arena Cove, Point Reyes, and San Francisco Bay.
Crescent City, historically vulnerable to tsunami amplification due to offshore bathymetry, sustained localized damage estimated at nearly 1 million USD. H Dock, a concrete floating structure engineered to break away under high wave stress, detached from its pilings and was destroyed as designed.
While the detachment protected inner harbor infrastructure, it caused damage to electrical lines, water supply, and fire suppression systems. Sediment and debris accumulation was also reported across the navigation channel.
No vessels were damaged, and no injuries were reported. Beach closures and harbor access restrictions remained in effect until water levels stabilized.
Japan reported tsunami wave heights up to 1.3 m (4.3 feet) along parts of its eastern coast. One indirect fatality and at least 21 injuries were attributed to the evacuation process.
In Chile, waves below 1 m (3 feet) were observed, prompting precautionary evacuations of over 1.4 million people.
A total of 426 earthquakes of magnitude 4.0 and above have been recorded along the Kamchatka Peninsula and northern Kuril Islands region over the past 7 days.
The M8.8 earthquake that struck off the Kamchatka Peninsula on July 29 is the largest earthquake globally since the M9.0 Tōhoku earthquake in Japan in 2011. It ranks as the sixth-strongest earthquake ever recorded instrumentally and is the most powerful to strike Russia since the M9.0 Kamchatka earthquake in 1952.
The last earthquake of comparable magnitude was the M8.8 Maule earthquake in Chile in 2010.
Estimated population exposure to earthquake shaking
Selected cities exposed
Regional seismicity
References:
1 M6.8 earthquake Kamchatka, Russia – USGS – August 3, 2025
2 M6.8 earthquake Kamchatka, Russia – EMSC – August 3, 2025
3 M6.8 earthquake Kamchatka, Russia – PTWC – August 3, 2025
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