Mount Hood volcano (Oregon, USA): earthquake M 3.9
mar., 8 juin 2021, 16:1016:10 PM | AUTEUR : MARTIN
On 5 June at 20:51 local time, the Cascade Volcano Observatory's (CVO) seismic network detected a volcano-tectonic earthquake with magnitude M 3.9 that occurred about 4 km south of the summit at 4.3 km depth.
Earthquakes from 5 June shown with red circles, yellow triangles are seismic stations (image: CVO)
It was preceded by several earthquakes in the hour prior to the M 3.9, and tens of aftershocks have occurred so far with event rates declining in a manner typical of mainshock-aftershock sequences. The earthquake was felt in the vicinity around the volcano.
The mainshock characteristics and location are consistent with past swarms in the Mount Hood area, including a M 4.5 on June 29, 2002, that was located ~1 mile east of the M 3.9. Aftershocks will likely continue for hours or days, some of which may be felt.
Seismologists from the CVO and Pacific Northwest Seismic Network don't indicate that the seicmic event could be related to volcanic hazard at the volcano.
Source: Cascade Volcano Observatory volcano activity update 8 June 2021
mer., 26 juin 2002, 06:00
Hood volcano (United States) - Smithsonian / USGS Weekly Volcanic Activity Report for 26 June-2 July 2002 (New Activity / Unrest)
CVO reported that the strongest earthquake in the Mount Hood area in decades occurred on 29 June at 0736. The widely felt M 4.5 event was located ~4.5 km S of the summit at a depth of 6 km. Hundreds of aftershocks followed, including two greater than M 3. ... Read all
mer., 12 sept. 2001, 06:00
Hood volcano (United States) - Smithsonian / USGS Weekly Volcanic Activity Report for 12 September-18 September 2001 (New Activity / Unrest)
The USGS Cascades Volcano Observatory reported that a minor earthquake swarm occurred at Mount Hood from 9 September until at least 14 September. About 25 events were detected, with a maximum magnitude of 2.9. The epicenters of the earthquakes were ~8 km SSW of the volcano's summit at depths of 1-7 km. ... Read all
mer., 17 janv. 2001, 06:00
Hood volcano (United States) - Smithsonian / USGS Weekly Volcanic Activity Report for 17 January-23 January 2001 (New Activity / Unrest)
The Cascades Volcano Observatory (CVO) reported that during 10-20 January a swarm of 13 earthquakes with magnitudes ranging from 0.2-2.0 occurred in an area about 4-8 km SSE of the summit at a depth of 4-7 km. This activity is not abnormal; Mount Hood averages one to two small swarms a year, with the last swarm occurring in May 2000. The current swarm consisted of fewer and smaller events than is typical, but it may not have yet ended. ... Read all