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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:
4 km ESE of Hebgen Lake Estates, Montana
Period:
18 Aug 2014 16:41:23 - 20 Aug 2014 08:00:52 (1 day 15 hours 19 minutes)
Volcanoes in 100km radius:
None
Earthquakes:
42
55 swarms found nearby.
2000
S20000125.1(17.2km)
25 Jan
1 day 8 hours
67 earthquakes
S20000329.2(15.9km)
29 Mar
9 days 3 hours
185 earthquakes
S20000409.1(15.8km)
8 Apr
1 day 23 hours
41 earthquakes
25 Oct
2 days 15 hours
52 earthquakes
S20001224.1(29.1km)
23 Dec
4 days 11 hours
64 earthquakes
2001
S20010119.1(17.8km)
18 Jan
4 days 18 hours
341 earthquakes
S20010227.1(16.8km)
26 Feb
2 days 5 hours
56 earthquakes
S20011202.1(13.3km)
2 Dec
5 days 0 hours
131 earthquakes
S20011209.3(11.4km)
8 Dec
19 days 5 hours
335 earthquakes
2002
S20020130.2(19.9km)
30 Jan
2 days 22 hours
52 earthquakes
S20021104.1(20.9km)
3 Nov
4 days 4 hours
118 earthquakes
S20021104.5(13.3km)
3 Nov
3 days 12 hours
80 earthquakes
S20021205.1(20.3km)
5 Dec
2 days 12 hours
405 earthquakes
S20021214.1(17.2km)
13 Dec
1 day 12 hours
26 earthquakes
2003
S20030103.2(29.4km)
3 Jan
4 days 3 hours
75 earthquakes
S20030206.1(13.8km)
5 Feb
1 day 18 hours
42 earthquakes
2004
S20040413.1(21.1km)
13 Apr
6 days 22 hours
457 earthquakes
16 Jul
1 day 16 hours
38 earthquakes
2005
3 Jun
2 days 8 hours
49 earthquakes
2006
S20060618.1(14.0km)
18 Jun
1 day 11 hours
57 earthquakes
2007
14 Dec
22 hours
28 earthquakes
S20071231.1(21.8km)
30 Dec
3 days 10 hours
61 earthquakes
2008
S20080109.1(21.0km)
9 Jan
4 days 20 hours
89 earthquakes
S20080807.1(28.4km)
7 Aug
6 hours
32 earthquakes
3 Dec
6 days 17 hours
213 earthquakes
2009
16 Apr
5 days 18 hours
136 earthquakes
12 Sep
21 hours
24 earthquakes
16 Sep
1 day 7 hours
28 earthquakes
2010
S20100117.1(28.6km)
16 Jan
19 days 8 hours
2268 earthquakes
2011
S20110504.1(10.6km)
3 May
1 day 22 hours
33 earthquakes
2013
S20130507.1(27.7km)
7 May
22 hours
34 earthquakes
29 Jun
3 days 16 hours
79 earthquakes
S20130713.1(22.5km)
13 Jul
19 hours
30 earthquakes
27 Sep
1 day 12 hours
28 earthquakes
S20131123.1(12.8km)
23 Nov
6 days 16 hours
223 earthquakes
2014
20 Aug
1 day 4 hours
40 earthquakes
2015
21 Jan
1 day 8 hours
135 earthquakes
13 Oct
1 day 20 hours
31 earthquakes
7 Nov
1 day 23 hours
85 earthquakes
2016
24 Sep
1 day 16 hours
46 earthquakes
2017
S20170612.3(12.4km)
12 Jun
45 days 12 hours
1542 earthquakes
S20170802.1(10.6km)
1 Aug
17 days 7 hours
784 earthquakes
20 Aug
4 days 18 hours
43 earthquakes
S20170827.1(14.0km)
27 Aug
3 days 8 hours
66 earthquakes
2018
S20180216.1(17.8km)
15 Feb
11 days 1 hours
728 earthquakes
2020
S20200509.3(17.0km)
9 May
2 days 5 hours
80 earthquakes
2021
S20210628.1(10.9km)
27 Jun
5 days 17 hours
230 earthquakes
2022
S20220329.1(23.1km)
28 Mar
2 days 12 hours
117 earthquakes
2023
S20230207.2(21.5km)
6 Feb
2 days 9 hours
63 earthquakes
13 Mar
1 day 18 hours
136 earthquakes
2024
S20240106.1(21.4km)
6 Jan
10 hours
35 earthquakes
23 Apr
4 days 7 hours
79 earthquakes
2025
4 Mar
12 hours
25 earthquakes
S20250507.1(11.0km)
7 May
8 hours
37 earthquakes
S20250830.1(27.1km)
29 Aug
3 days 9 hours
38 earthquakes
AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

Seismic Swarm S20140819.4 Near Hebgen Lake Estates, Montana

A seismic swarm designated S20140819.4 occurred approximately 4 km east-southeast of Hebgen Lake Estates in southwestern Montana. The sequence began at 16:41 on 18 August 2014 and concluded at 08:00 on 20 August 2014, spanning 39 hours and 19 minutes. During this period, 42 earthquakes were recorded, with magnitudes ranging from -0.2 to 1.9 and focal depths predominantly between 8 and 14 km.

The swarm exhibited typical characteristics of clustered microseismicity, featuring an initial burst of events on the evening of 18 August followed by sporadic activity through 19 August and a final event early on 20 August. Most events clustered around magnitudes 0.5–1.7, with the largest reaching 1.9 at 22:29 on 18 August. Depths remained relatively consistent near 11–12 km for the stronger shocks, though a few shallower events occurred around 2–9 km.

This activity took place within the Intermountain Seismic Belt, a north-trending zone of active normal faulting that extends from Arizona through Utah and Idaho into Montana. The Hebgen Lake region lies near the southern margin of this belt and is influenced by both Basin and Range extension and proximity to the Yellowstone volcanic system. The area is underlain by Precambrian metamorphic rocks and Paleozoic sedimentary sequences cut by Quaternary faults, including the Hebgen Lake fault responsible for the destructive magnitude 7.3 earthquake of 17 August 1959.

Historical records indicate recurrent swarm activity in the vicinity. Since 1 January 2000, 35 swarms have been documented in the region. Annual counts include five swarms each in 2000, 2002, and 2013; four in 2001; three each in 2008 and 2009; two each in 2003, 2004, and 2007; and single swarms in 2005, 2006, 2010, and 2011. Such episodic clustering is consistent with the tectonic regime of distributed normal faulting and possible fluid migration associated with regional geothermal systems.

The 2014 swarm did not produce any reported damage or felt shaking beyond instrumental detection, reflecting the low magnitudes involved. Continued monitoring of similar sequences contributes to understanding background seismicity rates and potential precursors to larger events along nearby faults.

References

USGS Earthquake Hazards Program
Montana Bureau of Mines and Geology seismic reports
International Seismological Centre catalog