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Note:This page contains AI-generated content for informational and entertainment purposes only. It may contain inaccuracies. Raw event data is from USGS and EMSC. All statistics, lists, and derived information are generated by this site. Full disclaimerFound an error?
Location:
28 km ENE of Lee Vining, California
Period:
20 Mar 2001 09:59:21 - 27 Mar 2001 00:53:56 (6 days 14 hours 54 minutes)
Volcanoes in 100km radius:
Mono Lake Volcanic Field(25km), Mono-Inyo Craters(35km), Mammoth Mountain(50km)
Earthquakes:
96
21 swarms found nearby.
2001
S20010308.1(23.5km)
7 Mar
2 days 6 hours
47 earthquakes
2004
S20040918.1(12.1km)
17 Sep
67 days 17 hours
4783 earthquakes
13 Dec
15 days 7 hours
237 earthquakes
2006
S20060505.1(21.5km)
5 May
1 day 14 hours
30 earthquakes
2008
15 Jan
2 days 10 hours
50 earthquakes
1 Feb
2 days 6 hours
54 earthquakes
2009
S20090831.1(12.9km)
30 Aug
2 days 4 hours
34 earthquakes
2011
S20110704.1(25.1km)
3 Jul
3 days 20 hours
49 earthquakes
2015
4 May
2 days 22 hours
111 earthquakes
9 May
2 days 3 hours
35 earthquakes
2016
S20160805.1(26.2km)
4 Aug
5 days 7 hours
205 earthquakes
S20161228.1(25.1km)
28 Dec
58 days 12 hours
4521 earthquakes
2017
S20170415.1(28.8km)
15 Apr
12 hours
83 earthquakes
S20171009.1(26.1km)
8 Oct
3 days 3 hours
371 earthquakes
15 Oct
16 hours
26 earthquakes
19 Oct
2 days 13 hours
33 earthquakes
2018
S20180207.1(24.9km)
7 Feb
2 days 14 hours
56 earthquakes
S20181207.1(13.4km)
7 Dec
1 day 2 hours
33 earthquakes
S20181217.1(13.4km)
17 Dec
2 days 9 hours
44 earthquakes
2020
11 Apr
33 days 8 hours
1019 earthquakes
2021
S20210115.1(20.6km)
15 Jan
1 day 14 hours
89 earthquakes
AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

Seismic Swarm S20010320.1 near Lee Vining, California

Seismic swarm S20010320.1 was recorded in the region 28 km east-northeast of Lee Vining, California, between 09:59 on 20 March 2001 and 00:53 on 27 March 2001. Over 158 hours and 54 minutes, the sequence comprised 96 earthquakes. All events were of low to moderate magnitude, with the largest reaching 3.3 at a depth of 7 km. Subsequent events were predominantly below magnitude 2.0 and occurred at shallow depths, mostly between 0 km and 7 km, with a single outlier at 11 km.

The temporal distribution shows the highest event rate during the first two days, followed by a gradual decline. Early activity on 20 March included multiple events exceeding magnitude 1.5 within the initial hours. Later stages featured isolated events of magnitude 1.8–2.2 on 21–24 March, after which activity tapered to isolated micro-earthquakes. Depths remained consistently shallow throughout, consistent with brittle failure in the upper crust.

The swarm occurred within the tectonically active western Basin and Range province, where distributed right-lateral shear accommodates motion between the Pacific and North American plates. The site lies near the eastern margin of the Sierra Nevada and adjacent to the Mono-Inyo volcanic chain. This setting hosts both tectonic and volcanic-related seismicity, with shallow crustal faults and possible fluid migration contributing to swarm behavior.

According to internal records maintained since 1 January 2000, this episode represents the sole swarm identified in the catalog for the area, with no additional swarms documented prior to 2001. The sequence therefore provides a baseline reference for regional swarm characteristics.

The provided event list indicates a typical swarm pattern: a rapid onset, absence of a single dominant mainshock, and decay without aftershock-style Omori decay. Magnitudes cluster below 2.0 after the initial day, while depths show limited variation, suggesting a compact source volume.

References

SeismoSight internal swarm classification S20010320.1
USGS Earthquake Catalog (regional context)
California Geological Survey, Mono County geologic maps