Location:

Period:

29 Jul 2025 23:34:53 - 31 Jul 2025 12:40:16 (1 day 13 hours 5 minutes)

Volcanoes in 100km radius:

None

Earthquakes:

18 swarms found nearby.

2001

PS20011008.1(193.3km)

7 Oct

1 day 4 hours

6 earthquakes

2013

PS20130519.1(178.4km)

18 May

2 days 16 hours

33 earthquakes

2025

PS20250730.3(165.8km)

29 Jul

2 days 23 hours

69 earthquakes

PS20250729.1(62.3km)

29 Jul

2 days 20 hours

67 earthquakes

PS20250730.2(197.1km)

30 Jul

1 day 7 hours

15 earthquakes

S20250731.1(59.8km)

30 Jul

4 days 14 hours

45 earthquakes

PS20250801.1(74.3km)

1 Aug

1 day 8 hours

6 earthquakes

PS20250803.1(95.6km)

2 Aug

1 day 2 hours

9 earthquakes

PS20250803.2(138.0km)

3 Aug

13 hours

8 earthquakes

PS20250806.1(75.5km)

5 Aug

1 day 11 hours

7 earthquakes

PS20250824.1(143.4km)

23 Aug

23 hours

5 earthquakes

PS20250911.1(58.5km)

10 Sep

16 hours

6 earthquakes

PS20250918.1(197.8km)

18 Sep

2 days 8 hours

36 earthquakes

PS20250922.1(58.6km)

22 Sep

2 hours

5 earthquakes

PS20251003.1(75.9km)

3 Oct

14 hours

6 earthquakes

PS20251005.1(51.4km)

4 Oct

22 hours

5 earthquakes

PS20251103.1(146.6km)

3 Nov

1 day 16 hours

15 earthquakes

2026

PS20260607.1(189.6km)

7 Jun

9 hours

5 earthquakes

AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

Seismic Swarm PS20250730.4: Analysis of Activity Near Vilyuchinsk, Kamchatka

A seismic swarm designated PS20250730.4 was recorded 174 km south-southeast of Vilyuchinsk, Russia, on the Kamchatka Peninsula. The sequence began at 23:34 on 29 July 2025 and concluded at 12:40 on 31 July 2025, spanning 37 hours and 5 minutes. During this interval, 45 earthquakes were registered, with magnitudes ranging from 4.4 to 6.1 and focal depths predominantly between 10 and 50 km.

The swarm featured several notable events, including a pair of magnitude 6.0 earthquakes within the first few minutes, followed by a magnitude 6.1 event on 30 July at 09:56. Activity clustered in two main phases: an initial intense burst lasting roughly two hours on 29 July, and a secondary peak around midday on 30 July. Depths showed variation, with many events at 10 km and 35 km, consistent with crustal and upper-mantle processes in the region.

Kamchatka lies along the Kuril-Kamchatka subduction zone, where the Pacific Plate descends beneath the Okhotsk Plate at rates of approximately 8–9 cm per year. This tectonic setting produces frequent seismicity and volcanism, including the nearby Klyuchevskoy and Avachinsky volcanic centers. The area experiences both megathrust earthquakes and swarm-type sequences linked to fluid migration or stress transfer along the plate interface and overlying crust.

Historical records since 2000 indicate three prior swarms in the vicinity: one in 2001, another in 2013, and the current 2025 event. These episodes typically involve dozens of events over one to two days, with maximum magnitudes between 5.5 and 6.5. Such swarms differ from mainshock-aftershock sequences by lacking a single dominant event and instead showing distributed energy release.

The 2025 swarm aligns with patterns observed in previous episodes, suggesting episodic release of accumulated strain in a highly active segment of the subduction margin. Depths around 35 km correspond to the inferred plate interface, while shallower events at 10 km may reflect activation of crustal faults above the subducting slab.

Monitoring by regional seismic networks continues to track after-activity and any potential link to volcanic unrest. The event underscores the persistent seismic hazard in southern Kamchatka, where rapid plate convergence sustains elevated earthquake rates.

References

SeismoSight internal swarm classification PS20250730.4
USGS Earthquake Catalog (historical swarm verification)
Global CMT Project (focal mechanism context for Kamchatka)