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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:
24 km S of Mina, Nevada
Period:
19 Dec 2020 10:00:28 - 27 Dec 2020 07:36:17 (7 days 21 hours 35 minutes)
Volcanoes in 100km radius:
None
Earthquakes:
133
24 swarms found nearby.
2003
S20030529.1(12.9km)
29 May
4 days 7 hours
164 earthquakes
15 Nov
2 days 1 hours
52 earthquakes
2013
S20130120.1(15.6km)
19 Jan
2 days 18 hours
65 earthquakes
S20130213.1(24.5km)
12 Feb
11 days 5 hours
345 earthquakes
2020
15 May
295 days 1 hours
21711 earthquakes
S20200516.1(27.0km)
15 May
32 days 11 hours
1150 earthquakes
S20200516.2(19.2km)
15 May
22 hours
26 earthquakes
16 May
11 days 1 hours
418 earthquakes
S20200528.1(19.4km)
27 May
17 days 11 hours
384 earthquakes
S20200615.1(22.6km)
14 Jun
31 days 0 hours
472 earthquakes
S20200708.2(26.6km)
7 Jul
5 days 6 hours
63 earthquakes
S20200726.1(27.7km)
25 Jul
11 days 0 hours
125 earthquakes
19 Oct
1 day 23 hours
31 earthquakes
2 Dec
8 days 6 hours
153 earthquakes
S20201211.1(25.8km)
10 Dec
1 day 1 hours
42 earthquakes
2021
S20210101.1(26.2km)
1 Jan
16 hours
24 earthquakes
S20210117.2(29.1km)
17 Jan
1 day 7 hours
25 earthquakes
29 Mar
19 days 16 hours
285 earthquakes
4 May
16 days 21 hours
229 earthquakes
26 Sep
2 days 0 hours
31 earthquakes
30 Sep
6 days 14 hours
87 earthquakes
S20211016.1(11.8km)
15 Oct
7 days 7 hours
86 earthquakes
S20211029.1(13.8km)
28 Oct
10 days 4 hours
136 earthquakes
2022
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 S20201220.1: Analysis of Activity South of Mina, Nevada

Seismic swarm S20201220.1 occurred approximately 24 km south of Mina in Mineral County, Nevada. The sequence began at 10:00 UTC on 19 December 2020 and concluded at 07:36 UTC on 27 December 2020, spanning 189 hours and 35 minutes. During this period, 133 earthquakes were recorded. The events clustered within a compact area typical of swarm behavior, where seismic energy releases through numerous small to moderate shocks rather than a single mainshock-aftershock sequence.

Analysis of the first 100 events reveals magnitudes ranging from 0.3 to 3.0, with the majority below 1.5. Depths predominantly varied between 0 and 15 km, consistent with shallow crustal faulting in the region. Notable events included a magnitude 3.0 earthquake at 17:43 UTC on 19 December at 4 km depth, followed closely by a 2.6 event. Later peaks featured magnitudes of 2.7 on 20 December and 2.1 on both 23 and 24 December. Temporal distribution showed highest frequency in the initial 48 hours, with activity gradually declining thereafter. Depths showed no strong systematic migration, though several events exceeded 10 km, indicating involvement of slightly deeper structures within the seismogenic zone.

This swarm fits into a broader pattern of seismic activity in western Nevada. Since 1 January 2000, fifteen swarms have been documented in the area, with notable clusters in 2003 (two swarms), 2013 (two swarms), and eleven in 2020 alone. Such recurrent swarms reflect ongoing tectonic strain accommodation.

The Mina region lies within the Walker Lane belt, a northwest-trending zone of right-lateral shear and crustal extension east of the Sierra Nevada. This tectonic province accommodates approximately 20 percent of the Pacific-North America plate motion through a combination of strike-slip and normal faulting. The local geology consists of Basin and Range-style horst-and-graben structures superimposed on older volcanic and sedimentary rocks. Active faults in the area, including segments of the Benton Spring and Petrified Spring fault systems, contribute to elevated seismicity rates compared to the stable continental interior.

Historical records indicate that Mineral County and adjacent regions have experienced multiple moderate earthquakes in the past century, underscoring the persistent seismic hazard. Swarm activity like S20201220.1 typically arises from fluid migration or aseismic slip on fault networks, though precise triggering mechanisms require further geophysical investigation. No damage or felt reports of significance were associated with this particular sequence, consistent with the low magnitudes observed.

Continued monitoring remains essential given the elevated swarm frequency recorded in 2020. Integration of seismic, geodetic, and geological data will improve understanding of strain accumulation and release along the Walker Lane.

References

  • U.S. Geological Survey Earthquake Catalog
  • Nevada Seismological Laboratory regional reports
  • USGS Professional Paper on Walker Lane tectonics