Mt Adams really isn't that far east

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drm
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Re: Mt Adams really isn't that far east

Post by drm » October 5th, 2021, 9:05 am

I withdraw my previous comment about it not being relevant. However, Adams and St Helens are almost exactly due east/west of each other and dozens of miles apart, so it's not like there is an exact boundary here. If Adams is not on the east side, then MSH is far to the west. And MSH is a lot more active than Adams.

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Re: Mt Adams really isn't that far east

Post by adamschneider » October 5th, 2021, 10:35 am

drm wrote:
October 5th, 2021, 9:05 am
If Adams is not on the east side, then MSH is far to the west.
That's for sure. And geologists are still trying to figure out how it all works underground. The latest evidence suggests that MSH is getting its magma from a source that's well to the east of the mountain itself.

Longview Daily News, 2015: First revelations about Mount St. Helens plumbing revealed this week

Nature Communications, 2016: Seismic evidence for a cold serpentinized mantle wedge beneath Mount St Helens

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Re: Mt Adams really isn't that far east

Post by jvangeld » October 5th, 2021, 11:29 am

From the Longview article
Part of the study involved detonating 23 explosive shots around the mountain, then tracking how the shock waves traveled through the earth.
Sometimes I wonder what kind of discussions the researchers have.

"Hey, you know how there were earthquakes right before Mt. St. Helens erupted?"

"Yeah!"

"Let's set off 23 mini-earthquakes and see what happens."

"Sounds great, let's do it!"
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Re: Mt Adams really isn't that far east

Post by drm » October 5th, 2021, 12:00 pm

I found an article this morning that says that study (with the explosives) showed that there is a large solid rock below Indian Heaven that is deflecting magma west, which is why MSH is that far west.

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Re: Mt Adams really isn't that far east

Post by retired jerry » October 5th, 2021, 12:25 pm

If they set off an explosive it releases shock waves that travel through the earth and get reflected off layers of different materials

They also have a set of transducers that pick up all the reflected shock waves

They can then analyze and figure out what layers there are at different locations and depths. They can see where magma is, properties of it, help predict when there might be an eruption.

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Re: Mt Adams really isn't that far east

Post by jvangeld » October 6th, 2021, 4:10 pm

I know they have serious discussions about the risks of their experiments, with far more technical words. But if you simplify it, it becomes kind of funny.
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Re: Mt Adams really isn't that far east

Post by retired jerry » October 7th, 2021, 5:35 am

yeah. Too bad they can't trigger an eruption with explosives?

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Re: Mt Adams really isn't that far east

Post by wildcat » October 24th, 2021, 11:00 am

I think another factor is that there is almost no access to the east side of Adams and no Cascades hiking east of it. It is the eastern edge for hikers. All the other peaks have hikes on their east side.
Is is a restricted/protected area or are there just no usable trails on that side?
However, Adams and St Helens are almost exactly due east/west of each other and dozens of miles apart
I have an FAA Seattle sectional chart (got it at Pearson a couple of weeks ago during a ride) and at first glance St. Helens and Adams are exactly due east/west of each other. If you use a ruler and trace across the map using the lateral scales as a reference, at least as far as summits are concerned, it appears Adams is actually very very very slightly east-northeast when measured from the St. Helens summit. The summits of all peaks are marked:
https://skyvector.com/?ll=46.2181751901 ... t=1&zoom=3
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Re: Mt Adams really isn't that far east

Post by adamschneider » October 24th, 2021, 11:19 am

wildcat wrote:
October 24th, 2021, 11:00 am
Is is a restricted/protected area or are there just no usable trails on that side?
The entire eastern half of Mt. Adams (and all the way to U.S. 97 and beyond) is on Yakama Nation land.

Yakama.jpg

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Re: Mt Adams really isn't that far east

Post by drm » October 25th, 2021, 7:12 am

My evidence for them being on an east-west line is from a camping trip on Adams on the September equinox some years ago at Crystal Lake. On the equinox the sun sets due west, and I watched it set into the crater of MSH.

But the center of the crater of MSH is not it's summit - that is on the southern rim, so that explains how the summit of MSH is a bit farther south. Something approximating the crater center (especially if there were a northern rim) looks like it would be as close to the same latitude of Adams as I can tell in that map.

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