Location:

Period:

4 May 2021 03:26:33 - 21 May 2021 00:45:53 (16 days 21 hours 19 minutes)

Volcanoes in 100km radius:

None

Earthquakes:

229

24 swarms found nearby.

2003

S20030529.1(12.1km)

29 May

4 days 7 hours

164 earthquakes

S20031116.1(8.8km)

15 Nov

2 days 1 hours

52 earthquakes

2013

S20130120.1(11.2km)

19 Jan

2 days 18 hours

65 earthquakes

S20130213.1(20.1km)

12 Feb

11 days 5 hours

345 earthquakes

2020

S20200515.1(2.3km)

15 May

295 days 1 hours

21711 earthquakes

S20200516.1(22.5km)

15 May

32 days 11 hours

1150 earthquakes

S20200516.2(14.8km)

15 May

22 hours

26 earthquakes

S20200517.1(12.4km)

16 May

11 days 1 hours

418 earthquakes

S20200528.1(15.3km)

27 May

17 days 11 hours

384 earthquakes

S20200615.1(18.2km)

14 Jun

31 days 0 hours

472 earthquakes

S20200708.2(22.1km)

7 Jul

5 days 6 hours

63 earthquakes

S20200726.1(23.1km)

25 Jul

11 days 0 hours

125 earthquakes

S20201020.3(11.9km)

19 Oct

1 day 23 hours

31 earthquakes

S20201203.1(10.8km)

2 Dec

8 days 6 hours

153 earthquakes

S20201211.1(21.2km)

10 Dec

1 day 1 hours

42 earthquakes

S20201220.1(4.6km)

19 Dec

7 days 21 hours

133 earthquakes

2021

S20210101.1(21.7km)

1 Jan

16 hours

24 earthquakes

S20210117.2(24.5km)

17 Jan

1 day 7 hours

25 earthquakes

S20210330.1(3.5km)

29 Mar

19 days 16 hours

285 earthquakes

S20210927.1(0.7km)

26 Sep

2 days 0 hours

31 earthquakes

S20211001.1(2.8km)

30 Sep

6 days 14 hours

87 earthquakes

S20211016.1(7.2km)

15 Oct

7 days 7 hours

86 earthquakes

S20211029.1(9.5km)

28 Oct

10 days 4 hours

136 earthquakes

2022

S20220105.1(2.0km)

4 Jan

6 days 14 hours

106 earthquakes

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

Seismic Swarm S20210505.1: Analysis of Activity Near Mina, Nevada

A seismic swarm designated S20210505.1 was recorded 34 km southeast of Mina, Nevada. The sequence began at 03:26 on 4 May 2021 and concluded at 00:45 on 21 May 2021, spanning 405 hours and 19 minutes. During this period, 229 earthquakes were detected.

Analysis of the first 100 events reveals predominantly low-magnitude activity. Magnitudes ranged from 0.2 to 4.4, with the majority below 2.0. Depths varied between 0 km and 14 km, indicating shallow crustal sources typical of the region. Notable events included a magnitude 2.6 quake on 4 May at 17:36:03 (depth 6 km), a magnitude 4.4 event on 8 May at 08:13:52 (depth 5 km), and a magnitude 3.6 shock on 9 May at 19:26:12 (depth 1 km). Temporal clustering showed elevated rates on 4–5 May and 8–9 May, consistent with swarm behavior rather than a mainshock-aftershock sequence.

The Mina area lies in western Nevada within the Basin and Range Province. This extensional tectonic regime features north-south trending normal faults that accommodate crustal stretching at rates of several millimeters per year. The local geology is influenced by the Walker Lane belt, a zone of distributed shear and transtension east of the Sierra Nevada. Historical seismicity in this portion of Nevada reflects ongoing fault slip along structures such as the Benton Spring Fault and related systems.

Since 2000, the region has experienced 19 documented swarms. These occurred in 2003 (2 swarms), 2013 (2 swarms), 2020 (12 swarms), and 2021 (3 swarms). Such recurrent swarm activity aligns with fluid-driven or aseismic slip processes common in the central Walker Lane, where episodic earthquake clusters often lack a dominant mainshock.

No damage or injuries were associated with swarm S20210505.1. The event underscores the persistent seismic hazard in rural western Nevada, where small-to-moderate events can occur without warning. Continued monitoring supports improved understanding of strain accumulation and release along regional faults.

References

U.S. Geological Survey Earthquake Catalog (earthquake.usgs.gov)
Nevada Seismological Laboratory historical data
SeismoSight internal swarm classification records