Low level seismic (swarm) activity at Mt Hood, Oregon

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Discussion Overview

The discussion centers around low-level seismic activity at Mount Hood, Oregon, specifically addressing a reported earthquake swarm. Participants explore the nature of the seismic events, their magnitudes, potential causes, and the relationship to volcanic activity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants report that the seismic activity consists of small earthquakes ranging from magnitudes 1 to 1.9, primarily located on the south side of Mount Hood.
  • Concerns are raised about the distance to the Yellowstone bubble, with one participant noting it is about 600 miles away, suggesting no direct relation to the Mount Hood activity.
  • There is uncertainty regarding the classification of an 'other event' mentioned in the seismic data, with suggestions that it may relate to human activities such as mining or fracking.
  • Some participants express surprise at the characterization of the seismic activity as tectonic rather than volcanic, prompting further verification of the information.
  • It is noted that Mount Hood is one of the most seismically active volcanoes in the region, with most earthquakes occurring in clusters around the volcano rather than directly beneath it.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of the seismic activity, with ongoing questions about the nature of the 'other event' and the relationship between tectonic and volcanic processes.

Contextual Notes

Participants highlight limitations in the data, including the ambiguity of the 'other event' and the need for clarification on the relationship between tectonic activity and volcanic processes at Mount Hood.

Astronuc
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A journalist reported a 'New Earthquake Swarm is Rocking Oregon's Mt Hood.
http://www.wired.com/2016/05/new-earthquake-swarm-rocking-mt-hood

I wouldn't say rocking.

I checked USGS, and didn't find anything over Mag 2.5, so I refined the search in the range of Mag 1 to 2.5, and found a number of small earthquakes in the range of 1 to 1.9 scattered around the south side of Mt. Hood just north of State Rd 35, and just east and south east of the Timberline ski area. The depths are about 3 to 4 km.

Code:
2016-05-17 00:17:39 UTC  3.5 km  1.0  23km ESE of Mount Hood Village, Oregon
2016-05-16 21:59:51 UTC  3.1 km  1.2  23km ESE of Mount Hood Village, Oregon
2016-05-16 21:50:07 UTC  2.9 km  1.7  Other Event 22km E of Mount Hood Village
2016-05-16 21:47:52 UTC  3.7 km  1.4  22km ESE of Mount Hood Village, Oregon
2016-05-16 21:47:40 UTC  3.5 km  1.4  23km ESE of Mount Hood Village, Oregon
2016-05-16 21:35:33 UTC  3.8 km  1.1  23km ESE of Mount Hood Village, Oregon
2016-05-16 19:30:45 UTC  3.2 km  1.0  23km ESE of Mount Hood Village, Oregon
2016-05-16 16:48:35 UTC  3.6 km  1.3  22km ESE of Mount Hood Village, Oregon
2016-05-16 14:31:03 UTC  3.4 km  1.7  22km E of Mount Hood Village, Oregon
2016-05-16 13:53:50 UTC  3.8 km  1.4  22km ESE of Mount Hood Village, Oregon
2016-05-16 13:45:54 UTC  3.6 km  1.5  21km E of Mount Hood Village, Oregon
2016-05-16 13:39:20 UTC  3.3 km  1.9  22km E of Mount Hood Village, Oregon
2016-05-16 13:30:08 UTC  4.2 km  1.4  22km ESE of Mount Hood Village, Oregon
2016-05-16 13:26:56 UTC  3.8 km  1.1  23km ESE of Mount Hood Village, Oregon
2016-05-16 13:21:30 UTC  4.1 km  1.2  22km ESE of Mount Hood Village, Oregon
2016-05-16 13:17:22 UTC  2.6 km  1.4  21km ESE of Mount Hood Village, Oregon
2016-05-16 13:02:33 UTC  4.2 km  1.3  22km ESE of Mount Hood Village, Oregon
2016-05-16 12:53:31 UTC  3.9 km  1.7  23km ESE of Mount Hood Village, Oregon
2016-05-16 12:30:49 UTC  3.8 km  1.1  22km ESE of Mount Hood Village, Oregon
2016-05-16 12:19:43 UTC  3.6 km  1.8  22km ESE of Mount Hood Village, Oregon
2016-05-16 12:03:38 UTC  4.0 km  1.6  23km E of Mount Hood Village, Oregon
2016-05-16 12:03:33 UTC  3.7 km  1.5  22km ESE of Mount Hood Village, Oregon
2016-05-16 11:54:59 UTC  4.0 km  1.2  22km ESE of Mount Hood Village, Oregon
2016-05-16 11:43:48 UTC  3.1 km  1.6  22km E of Mount Hood Village, Oregon
2016-05-16 10:55:00 UTC  3.5 km  1.3  22km ESE of Mount Hood Village, Oregon
2016-05-16 10:39:08 UTC  3.8 km  1.5  23km ESE of Mount Hood Village, Oregon
2016-05-16 10:10:11 UTC  3.6 km  1.1  22km ESE of Mount Hood Village, Oregon
2016-05-16 09:02:55 UTC  3.2 km  1.5  21km ESE of Mount Hood Village, Oregon
2016-05-16 08:53:15 UTC  3.8 km  1.5  23km ESE of Mount Hood Village, Oregon
2016-05-16 08:28:25 UTC  3.6 km  1.2  22km ESE of Mount Hood Village, Oregon
2016-05-16 06:33:10 UTC  3.6 km  1.5  22km E of Mount Hood Village, Oregon
2016-05-16 06:19:36 UTC  3.2 km  1.6  22km ESE of Mount Hood Village, Oregon
2016-05-16 05:56:23 UTC  2.6 km  1.3  22km ESE of Mount Hood Village, Oregon
2016-05-16 05:25:53 UTC  3.5 km  1.1  23km ESE of Mount Hood Village, Oregon
2016-05-16 05:24:41 UTC  3.8 km  1.1  22km ESE of Mount Hood Village, Oregon
2016-05-16 05:07:56 UTC  3.8 km  1.5  22km ESE of Mount Hood Village, Oregon
2016-05-16 02:07:19 UTC  4.1 km  1.1  22km ESE of Mount Hood Village, Oregon
2016-05-16 01:38:33 UTC  3.3 km  1.5  22km E of Mount Hood Village, Oregon
2016-05-16 01:17:42 UTC  4.3 km  1.1  22km ESE of Mount Hood Village, Oregon

2016-05-13 12:09:43 UTC  4.4 km  1.1  20km E of Mount Hood Village, Oregon

I'm not sure what is the 'other event'.
 
Last edited:
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Astronuc said:
A journalist reported a 'New Earthquake Swarm is Rocking Oregon's Mt Hood.
http://www.wired.com/2016/05/new-earthquake-swarm-rocking-mt-hood

I wouldn't say rocking.

I checked USGS, and didn't find anything over Mag 2.5, so I refined the search in the range of Mag 1 to 2.5, and found a number of small earthquakes in the range of 1 to 1.9 scattered around the south side of Mt. Hood just north of State Rd 35, and just east and south east of the Timberline ski area.
Beside the low magnitude. How far is the Yellowstone bubble? This distance concerns me whenever I hear about an earthquake in the US.
 
fresh_42 said:
Beside the low magnitude. How far is the Yellowstone bubble? This distance concerns me whenever I hear about an earthquake in the US.
About 600 miles from Yellowstone, so it's not related. Mt Hood is one of numerous Cascade volcanoes. Hood's last eruption was about 200 years ago.
 
Astronuc said:
I'm not sure what is the 'other event'.

usually refers to something caused by human activity ... mining blast, mine collapse, fracking, etc etc

but noted tho that this "other Event" is in the same area as the other events
so maybe just not well defined ??
 
davenn said:
but noted tho that this "other Event" is in the same area as the other events
so maybe just not well defined ??
I downloaded the data after I saw this thread, and it appears they've thrown that reading out.

I was also surprised to see in the Wired article that this was tectonic activity, and not volcanic, so I double checked that.

Seismic Monitoring at Mount Hood, Oregon [USGS]
Mount Hood is one of the most seismically active volcanoes in the Washington and Oregon Cascades, and the most seismically active volcano in Oregon. In an average month 1-2 earthquakes are located by the Pacific Northwest Seismic Network (PNSN) within 3 miles of the summit. Most Hood earthquakes don't actually occur directly beneath the volcano's summit, but instead in one of several clusters located 2-5 km west, southwest, and southeast of the summit.
...
Scientists believe that earthquakes in the clusters south of the summit occur on tectonic faults and aren't directly related to volcanic processes occurring beneath Mount Hood.

Here's a neat little info-graphic of how often the Cascade volcanoes have erupted over the last 4000 years:

img1052_623w_500h.eruptions.of.cascade.mountains.last.4000.years.jpg

[ref]
 
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