Location:

Period:

27 May 2018 16:11:12 - 28 May 2018 12:15:08 (20 hours 3 minutes)

Volcanoes in 100km radius:

Soda Lakes(90km)

Earthquakes:

49 swarms found nearby.

2003

S20031003.1(25.2km)

3 Oct

1 day 20 hours

34 earthquakes

S20031009.1(6.9km)

8 Oct

2 days 19 hours

40 earthquakes

S20031123.1(23.5km)

22 Nov

2 days 23 hours

36 earthquakes

2004

S20040603.1(6.5km)

2 Jun

8 days 0 hours

197 earthquakes

S20040612.1(25.0km)

12 Jun

1 day 20 hours

35 earthquakes

2005

S20050521.1(20.9km)

21 May

1 day 10 hours

39 earthquakes

S20050626.1(20.7km)

26 Jun

4 days 0 hours

149 earthquakes

S20050918.1(11.8km)

17 Sep

2 days 13 hours

34 earthquakes

S20051207.2(23.2km)

7 Dec

2 days 20 hours

40 earthquakes

2007

S20070509.1(21.2km)

8 May

2 days 16 hours

36 earthquakes

2008

S20080308.1(12.0km)

8 Mar

2 days 8 hours

85 earthquakes

S20080314.1(12.4km)

14 Mar

26 days 23 hours

841 earthquakes

S20080411.1(8.7km)

11 Apr

55 days 20 hours

13408 earthquakes

S20080608.1(13.0km)

7 Jun

20 days 22 hours

426 earthquakes

S20080712.1(11.3km)

12 Jul

20 hours

33 earthquakes

S20080730.1(15.4km)

29 Jul

4 days 1 hours

76 earthquakes

S20081121.2(8.3km)

21 Nov

1 day 17 hours

26 earthquakes

2010

S20101204.1(5.0km)

3 Dec

1 day 22 hours

32 earthquakes

2012

S20120408.2(10.8km)

8 Apr

2 days 17 hours

45 earthquakes

S20120623.1(11.9km)

22 Jun

1 day 13 hours

37 earthquakes

S20120627.1(12.6km)

26 Jun

3 days 22 hours

58 earthquakes

2013

S20130304.1(26.0km)

3 Mar

1 day 4 hours

32 earthquakes

S20130314.1(24.1km)

13 Mar

1 day 19 hours

44 earthquakes

S20130317.1(25.9km)

17 Mar

1 day 18 hours

135 earthquakes

S20130321.2(25.3km)

20 Mar

5 days 20 hours

251 earthquakes

S20130325.1(5.7km)

24 Mar

1 day 1 hours

36 earthquakes

S20130728.1(22.7km)

27 Jul

1 day 0 hours

25 earthquakes

S20130731.1(25.4km)

31 Jul

2 days 18 hours

57 earthquakes

2014

S20140404.2(25.2km)

3 Apr

1 day 13 hours

40 earthquakes

S20140619.1(29.5km)

19 Jun

1 day 17 hours

115 earthquakes

S20140623.1(9.6km)

22 Jun

1 day 19 hours

28 earthquakes

2015

S20150127.1(9.3km)

26 Jan

4 days 13 hours

73 earthquakes

S20150408.1(10.0km)

8 Apr

2 days 9 hours

57 earthquakes

S20151018.1(16.4km)

18 Oct

1 day 6 hours

38 earthquakes

S20151223.1(12.0km)

23 Dec

1 day 7 hours

136 earthquakes

2016

S20160319.2(7.7km)

18 Mar

20 hours

29 earthquakes

S20161124.1(11.0km)

23 Nov

2 days 6 hours

34 earthquakes

2017

S20170729.1(9.8km)

29 Jul

14 hours

26 earthquakes

2018

S20180112.1(15.1km)

12 Jan

8 days 3 hours

354 earthquakes

S20180522.1(29.3km)

22 May

15 hours

26 earthquakes

S20180726.1(25.0km)

26 Jul

1 day 8 hours

40 earthquakes

2019

S20190619.1(19.5km)

19 Jun

1 day 5 hours

103 earthquakes

S20190911.1(20.4km)

11 Sep

18 hours

26 earthquakes

2023

S20230602.1(23.4km)

1 Jun

3 days 5 hours

45 earthquakes

S20230918.1(24.5km)

18 Sep

15 hours

41 earthquakes

S20231230.1(19.8km)

29 Dec

4 days 23 hours

117 earthquakes

2024

S20240126.1(25.1km)

25 Jan

2 days 3 hours

57 earthquakes

S20240129.1(19.0km)

28 Jan

5 days 10 hours

90 earthquakes

S20240214.1(17.8km)

13 Feb

2 days 18 hours

70 earthquakes

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

Seismic Analysis of Swarm S20180528.1 Near Floriston, California

Earthquake swarm S20180528.1 occurred approximately 9 km east-northeast of Floriston, California, in the northern Sierra Nevada region. The sequence began at 16:11 on 27 May 2018 and concluded at 12:15 on 28 May 2018, spanning 20 hours and 3 minutes. During this period, 24 earthquakes were recorded, with magnitudes ranging from -0.3 to 1.0 and focal depths between 6 and 8 km.

The swarm initiated with a magnitude 0.4 event at 7 km depth, followed rapidly by additional small events clustered within the first hour. Subsequent activity included several events of magnitude 0.5 to 1.0, interspersed with micro-earthquakes below magnitude 0.3. The sequence featured two magnitude 1.0 events, one at 16:50:09 on 27 May and another at 05:52:50 on 28 May, both at depths of 7–8 km. Activity tapered off toward the end, with the final event registering magnitude 0.7 at 7 km depth.

This swarm aligns with the tectonic setting of the region, where the Sierra Nevada experiences distributed deformation along normal and strike-slip faults associated with the broader Walker Lane belt. The area has a documented history of seismic swarms driven by fluid migration or minor stress adjustments in the crust, rather than large mainshock-aftershock sequences. Depths consistently in the 6–8 km range suggest activity within the brittle upper crust typical of this part of the Sierra Nevada.

Historical data indicate that 40 swarms have occurred in the vicinity since 1 January 2000. Yearly counts show variability, with peaks in 2008 and 2013 (seven swarms each) and lower activity in intervening years such as 2007, 2010, and 2017 (one swarm each). The 2018 total of two swarms, including S20180528.1, reflects moderate ongoing seismicity in the zone.

Such swarms provide insight into local fault behavior and can serve as indicators of subtle changes in regional stress. Continued monitoring remains essential given the proximity to populated areas near Lake Tahoe and major transportation corridors.

References

SeismoSight internal swarm classification database
USGS Earthquake Catalog (historical verification)