Location:

Period:

3 Oct 2024 17:59:39 - 6 Oct 2024 10:07:01 (2 days 16 hours 7 minutes)

Volcanoes in 100km radius:

Denison(22km), Kukak(23km), Steller(23km), Snowy Mountain(26km), Griggs(34km), Katmai(36km), Kaguyak(38km), Novarupta(44km), Trident(45km), Mageik(53km), Martin(59km), Fourpeaked(62km), Douglas(72km), Unnamed(89km)

Earthquakes:

6 swarms found nearby.

2002

S20020715.1(26.4km)

14 Jul

1 day 0 hours

27 earthquakes

2019

VS20190820.1(28.1km)

20 Aug

1 day 22 hours

61 earthquakes

2020

VS20200115.1(19.4km)

14 Jan

1 day 11 hours

81 earthquakes

S20200126.1(27.4km)

25 Jan

3 days 12 hours

54 earthquakes

S20200223.2(21.9km)

23 Feb

1 day 0 hours

26 earthquakes

VS20200814.1(27.9km)

14 Aug

3 days 14 hours

68 earthquakes

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

Seismic Swarm S20241004.1: Analysis of Activity South of Kokhanok, Alaska

Seismic swarm S20241004.1 occurred approximately 97 km south of Kokhanok, Alaska, on the Alaska Peninsula. The sequence began at 17:59 UTC on 3 October 2024 and concluded at 10:07 UTC on 6 October 2024, spanning 64 hours and 7 minutes. During this period, 46 earthquakes were recorded, with magnitudes ranging from -0.3 to 4.2 and focal depths between 1 km and 14 km.

The swarm exhibited a typical pattern for the region, with the majority of events below magnitude 1.0 and a small number of moderate shocks. The largest event, magnitude 4.2, occurred at 01:49 UTC on 4 October at a depth of 4 km. Additional notable events included a magnitude 3.2 shock at the swarm's onset and a magnitude 2.3 event late on 5 October. Depths remained predominantly shallow, consistent with upper-crustal faulting.

This activity took place within the tectonically active Aleutian subduction zone, where the Pacific Plate converges with and subducts beneath the North American Plate at rates of approximately 6–7 cm per year. The resulting compressional stress produces frequent earthquakes along the megathrust and associated crustal faults. The Kokhanok area lies near the volcanic arc, including Iliamna Volcano, where magma movement and hydrothermal systems can also contribute to localized seismicity.

Since 1 January 2000, six swarms have been documented in the immediate vicinity. These occurred in 2002 (one swarm), 2019 (one swarm), and 2020 (four swarms). Such episodic clusters are common in subduction-related settings and do not necessarily indicate an increased likelihood of a larger mainshock.

The shallow depths and rapid succession of events suggest activation of a localized fault network rather than deep slab processes. No surface rupture or significant ground deformation has been associated with this swarm based on available regional monitoring.

References

SeismoSight internal swarm classification S20241004.1
USGS Earthquake Hazards Program – Alaska seismicity reports
Alaska Earthquake Center – regional tectonic summaries