A New Earthquake Swarm Is Rocking Oregon’s Mt. Hood

[Lodestar]

Source: Wired

A FEW WEEKS back, we heard news of an small earthquake swarm underneath Mount St. Helens. Now, media-driven hyperbole aside, that swarm was business-as-usual for a Cascade volcano, where magma slowly rises back into the upper parts of the system. So, it should be no surprise when other volcanoes in the range show similar behavior. That’s what we might be seeing right now at St. Helens’ southern neighbor, Oregon’s Mt. Hood, where the USGS has noticed a swarm of small earthquakes (all less than M2) that started on Sunday.

It has been over 200 years since Hood’s last eruption, a period that is referred to as the “Old Maid” eruptive period when a small lava dome was formed just off the volcano’s summit. This activity produced some pyroclastic flows that swept down the southeastern sides of the volcano, along with some lahars (volcanic mudflows) that headed down some of the rivers that come off of Hood, like the Sandy River (see below). The Sandy got its name thanks to what may have been lahar deposits in its channel when Lewis and Clark came by a few years after the eruptions. A few small explosions likely occurred during the 1800s, but since about the 1860s, the volcano has been completely quiet.

Read more: http://www.wired.com/2016/05/new-earthquake-swarm-rocking-mt-hood/

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[hobbit709]

1. The question is always "When?"

I try to avoid places where the ground moves or the mountains smoke.

[cstanleytech]

2. No, the real question starts with "Why".

Why do people choose to live in high risk areas be it near volcanoes or in cities like New Orleans?

[Javaman]

4. every place as a "risk"

Hood hasn't been active for 200 years. so living there is now a problem?

>shakes head in wonder<

[cstanleytech]

6. That's certainly true however I just dont understand why people are

willing to live in areas that they know have a higher chance than others of having a major disaster such as living next to a volcano or in an area known to suffer from severe flooding.

[Javaman]

7. I lived in Southern California.

I was in the Northridge quake.

I worked in the film industry. I didn't have much of a choice at the time, if I wanted to continue to feed myself.

People died in that quake.

I was born and raised in NYC, we have hurricanes and horrible Ice storm winters with lost of power.

people die every year from both those things.

I now live in central texas and we have severe storms and tornadoes.

people die in those virtually every time.

we are, as a species, adaptable. And being adaptable, also means risks.

if we don't take risks, which I believe is an inherent trait to our species, we wouldn't advance.

your question is actually no different than asking; why do people explore caves? why do people become astronauts? why do people climb the highest mountains? Why do people do the many many things that we do as a species?

The very simple answer is: because we can.

We seem to forget that on a daily basis.

and remember this: just because you can't comprehend why people choose to live where they live, there are people out there that ask the very same questions about you.

if we are anything, we are resilient.

[cstanleytech]

8. They can ask it of me all they want because I dont live in an area prone to suffer from

severe floods, volcanoes or earthquakes.

[Baobab]

13. I used to know a hippie guy who literally lived through the Mt. St Helens eruption- he was lucky to

have escaped with his life.

His story was incredible. Basically he was at Spirit Lake and the explosion knocked both him and all the trees down all around him but he miraculously was only burned and not buried under trees. There were burning things and ice all around him and he walked out. He used his bandanna over his face.

He was a juggler. A professional juggler, a really good one.

The explosion singed off most of his hair and beard.

He used aloe vera and comfrey tea on the burns. Aloe vera is the best thing for burns. It works miracles on burns.

[Wibly]

9. Why live anywhere?

Of Kansas with its Tornadoes, or New York with its pollution, or Michigan with its tainted water, or the Mississippi lowlands with its flooding, or the north because of the cold, or the south because of the heat, or the east because of the bugs, or the mountians because of avalanches.
Look out, wherever you are, there is something either natural or man made that could kill you.
Maybe we should get off earth because it might get hit by a meteor.
OMG!

[Baobab]

14. There are few natural phenomena as potentially devastating to humanity as volcanism.

Volcanic eruptions in the past have caused massive loss of life and even climate change.

The eruption of Santorini around 1600 BC basically utterly changed the Mediterranean area, wiping out the Minoan civilization and setting the area back at least a thousand years in terms of quality of life. Literacy died out so otally that nobody knows how to translate Linear A, the writing of the Minoan Crete civilization because there is no "Rosetta Stone" for it as there was later, cities shrunk drastically and became walled, stature of people living at the time shrunk.

That eruption was the one described in the Old Testament of the Bible as the plagues of Egypt.

It caused unseasonably cold and damp weather all around the globe for several years which must have caused the deaths of some significant portion of the world's population from famine.

[panader0]

3. When I was a thinner, contracting from the Forest Service,

our units were near to Mt Hood. I got my mail general delivery at Government Camp.
From some of our units we could see Mt St Helens (this was before the eruption).
A very beautiful place. The Timberline Lodge on Mt Hood is a great example of WPA and CCC
construction. It'd be a shame if an earthquake damaged it.

[Sunlei]

5. Last eruptions were 'smallish'? In the past those Mts volcanos flattened the entire state.

I remember reading, about 200?or less? years ago a large rockfall into the big river caused a tsunami wave to move down river, 100 feet high. And Mt. St. Helens usually erupts twice, quite close together in years.

[happyslug]

12. As to eruptions, the concern is NOT Mt Hood, but Mr Rainier in Washington State

Mt Rainier is the huge monster that can wipe out the Northwest and it is believe it has done so in the past, but it appears NOT to have had an eruption in 2200 years. If it does erupt, Seattle and Tacoma are gone....

https://en.wikipedia.org/wiki/Mount_Rainier

Age measurements of lavas and ashes from Mount Rainier show that the most recent lava flows erupted close to 2,200 years ago, and that pyroclastic flows erupted as recently as 1,100 years ago. Although there are several 19th century reports of dark clouds at the summit, interpreted by observers as small eruptions, no ash or other related volcanic deposits have been found to confirm such recent activity. Scientific examination of sparse pumice formerly thought to have erupted between 1820 and 1850, instead shows that this is 2,200 year old pumice. Mount Rainier has been active for the last 500,000 years; so the 2,200–year interval since the last known lava eruption is less than half a percent of the lifespan of the volcano.

https://volcanoes.usgs.gov/volcanoes/mount_rainier/geo_hist_summary.html

https://volcanoes.usgs.gov/volcanoes/mount_rainier/

As to debris falling into the river, Mt Baker had one in 2007, but appears to have been contained:

https://en.wikipedia.org/wiki/Mount_Baker

[happyslug]

10. Mt Hood averages a major eruption once every 600 to 750 years.

Mount Hood volcano.... The volcano has erupted episodically for about 500,000 years and hosted two major eruptive periods during the past 1,500 years. During both recent eruptive periods, growing lava domes high on the southwest flank collapsed repeatedly to form pyroclastic flows and lahars that were distributed primarily to the south and west along the Sandy River and its tributaries. The last eruptive period began in AD 1781 and affected the White River as well as Sandy River valleys. The Lewis and Clark Expedition explored the mouth of the Sandy River in 1805 and 1806 and described a river much different from today's Sandy. At that time the river was choked with sediment generated by erosion of the deposits from the eruption, which had stopped about a decade before their visit. In the mid-1800's, local residents reported minor explosive activity, but since that time the volcano has been quiet.

http://volcanoes.usgs.gov/volcanoes/mount_hood/

The last three eruptions at Mount Hood occurred within the past 1,800 years from vents high on the southwest flank and produced deposits that were distributed primarily to the south and west along the Sandy and Zigzag rivers. The last eruptive period took place around 220 to 170 years ago, when dacitic lava domes, pyroclastic flows and mudflows were produced without major explosive eruptions. The prominent Crater Rock just below the summit is hypothesized to be the remains of one of these now-eroded domes. This period includes the last major eruption of 1781 to 1782 with a slightly more recent episode ending shortly before the arrival of Lewis and Clark in 1805. The latest minor eruptive event occurred in August 1907.

https://en.wikipedia.org/wiki/Mount_Hood

Now, there appears to be no SCHEDULE eruption period, thus this COULD be a start of such a period, but in most likely the case it is NOT (To soon since the last eruption in the 1780s).

[MissB]

11. Still going to let my teenager summit the mountain

this weekend, unless weather conditions prevent it.

Or unless the mountain blows.

[maxsolomon]

15. not going to stress it

because there's nothing I can do about it except ride it out.

odds are really really good nothing's going to happen.