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Multifault earthquake threat for Seattle region revealed by mass tree mortality

science.org

121–130 of 149 posts

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#121
post #67

Earlier quoted context omitted.

That New Yorker article goes viral every few years - it's a well written piece and spins a great yarn, but there's some significant hyperbole and it's sources don't quite back up the claims. Yes, a 9.x will be devastating. No, everything west of i-5 will not be toast.

Good thing I'm 10 miles east from that road of doom, I'm sure I'll be safe ;-).

I'm 10 blocks east, should be fine too. Even if the earthquake somehow gets a couple blocks past I-5 (can't see how that could happen) I'd still have 7-8 blocks as a safety cushion.

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#122

A particularly crazy thing I learned from some friends who I know who work in this field is that they use underwater hydraulic chainsaws (!) to sample some of these trees. https://www.stanleyinfrastructure.com/products/underwater-ch... The field work in general seems very wet for this kind of research. (my partner did lots of it for her graduate work)

Harvesting timber from trees submerged by the creation of reservoirs is a viable business, I believe, on account of rising prices, particularly for high-quality lumber that is becoming scarce.

I suspect there's still plenty of much, much easier to access trees. The macro-economic effects of the wars, and covid, often causing gasoline prices increases (which is used a lot in forestry) that are still adding pressure to almost all commodity prices, including lumber

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#123

I wasn't involved in this study, but I wrote the study that estimated the magnitude of this earthquake[0]. In case anyone is interested, usually the magnitudes of 'paleoearthquakes' (historic/prehistoric earthquakes discovered by finding evidence of old ground deformation) are estimated by relating the measured offset of the earth's surface or a rock/dirt layer across the fault line to the earthquake magnitude throug…

In the late 90s, I took a geology course at Seattle Central, and the teacher told us the reason Alki Point has such a nice flat area all along the beach is because that area used to be the tide flats, but during an ancient earthquake, that entire chunk of West Seattle rose something like 10m in less than a minute and retained that elevation from then on. Is that still the current understanding?

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#124

Earlier quoted context omitted.

The Cascadia quake will be about same damage to Seattle and Portland as Bay Area quake. It could be up to magnitude 9 but the fault is 60 mi away from the cities. The big difference is that it will affect the whole area. And that PNW is way behind in infrastructure.

According to https://www.sfchronicle.com/projects/2023/bay-area-earthquak... vs https://www.newyorker.com/magazine/2015/07/20/the-really-big... you're looking at two orders of magnitude difference in terms of the estimate of people affected. I'm not sure what led to the difference but that's striking.

The news articles exaggerate things either for effect or didn’t realize quakes diminish with distance. The shaking for mag 9 at Portland is similar to mag 7 nearby. One difference is that quake will go on for minutes making liquefaction worse.

There will be lots of damage in Portland. There are lots of unreinforced masonry that will collapse and kill occupants. Most of the bridges, big and small won’t survive cutting off from outside. Infrastructure will be destroyed and utilities will be out of months. All of those could be upgraded which is why Bay Area would be in better shape.

Also, this is talking about Portland and Seattle. Most of the destruction will be on the coast which is closer to the fault. The tsunami will cause lots of damage, destroying most of the towns and killi;g everyone that doesn’t evacuate to high ground.

The 2011 Japan quake is the best comparison but Portland/Seattle aren’t prepared like Tokyo, and there are minimal tsunami defenses.

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#125
post #122

Earlier quoted context omitted.

Harvesting timber from trees submerged by the creation of reservoirs is a viable business, I believe, on account of rising prices, particularly for high-quality lumber that is becoming scarce.

I suspect there's still plenty of much, much easier to access trees. The macro-economic effects of the wars, and covid, often causing gasoline prices increases (which is used a lot in forestry) that are still adding pressure to almost all commodity prices, including lumber

It's not "access to trees" so much as "access to large, old growth trees". The old ones with tight growth rings, large widths and long straight trunks are actually kinda rare these days. The farmed stuff is not the same, compare the growth ring per-inch

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#126
post #30

Earlier quoted context omitted.

On the other hand, Seattle is one of the best places in the world to ride out climate change, which is 100% happening, and happening already. It’s all a numbers game.

I wish we were less focused on moving to where we can survive this mess and more focused on solving it, personally.

Individuals can do more to pick a better place to shelter than they can do to get everyone to stop making the problem worse, no?

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#127
post #90
post #67

Earlier quoted context omitted.

Good thing I'm 10 miles east from that road of doom, I'm sure I'll be safe ;-).

You gotta worry about lahars. :)

Not where I am. Mt Rainier can't reach me but maybe the mountains of Mordor could spring up? Maybe a new volcano, would take a while to build up. An earthquake can get me, I'm by one of the freshwater lakes, so there's possible water action that could get me. But probably the land is terrible by the lake, could subside, and then a wave of water will crush and then drown me.

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#128
post #126

Earlier quoted context omitted.

I wish we were less focused on moving to where we can survive this mess and more focused on solving it, personally.

Individuals can do more to pick a better place to shelter than they can do to get everyone to stop making the problem worse, no?

There's always some excuse why we can't even talk about trying in earnest to solve it.

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#129
post #25

Earlier quoted context omitted.

This article actually is loaded with inaccuracies. I once called the local earthquake office where I live, where the local scientists and such work. They said this article is the bane of their existence because of people calling into their office with false beliefs that have just propagated into fear over time. I dont even think the sentence got out of my mouth "so about that article I saw...", I was calling to see i…

Is there a better resource?

Sadly she didn't give one, however.. if you live near the CSZ like I do, then check your city to see who does their flood maps, and then call that office. For my area specifically they had a whole branch devoted to earthquakes called the earthquake office or something.

I picked her brain for about an hour, asking about all different questions about liklihood of tsunami, how far inland, I asked her stuff about my foundation and my house etc.

Id say it would be worthwhile to try and call your local office.

Re: Multifault earthquake threat for Seattle region revealed by mass tree mortality

#130
post #122

Earlier quoted context omitted.

Harvesting timber from trees submerged by the creation of reservoirs is a viable business, I believe, on account of rising prices, particularly for high-quality lumber that is becoming scarce.

I suspect there's still plenty of much, much easier to access trees. The macro-economic effects of the wars, and covid, often causing gasoline prices increases (which is used a lot in forestry) that are still adding pressure to almost all commodity prices, including lumber

Nevertheless, it is actually happening:

https://grist.org/article/greenemeier-waterlog/

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