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The Orphan Tsunami of 1700 [pdf]

33 points| oliverkwebb | 4 months ago |pubs.usgs.gov

16 comments

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ogogmad|4 months ago

Just learnt something from the article: It's interesting that the warping of the seafloor is what causes tsunamis, and not the shaking itself. It explains why a shoreline might sometimes recede away before a tsunami's crest strikes: The recession is caused by the seawater dropping with the seafloor, while the forward surge is caused by the ensuing bounce.

pixl97|4 months ago

Dropping or rising. At the borders of the sea and land plates the sea plates are slipping slowly below the continental crust. Pieces of the land crust get caught and dragged down. Over long periods of time you'll see forested land get dragged down below sea level and flooded to die.

The a rupture will occur, and in the biggest earthquakes you can get a fault that can rise 20 meters almost instantly causing trillions of tons of ocean to suddenly have to go somewhere. After the quake and tsunami you'll see the flooded forests can be many meters above land were new forest will grow and slowly start sinking again.

jmward01|4 months ago

Cascadia has become a little bit of an obsession for me. I had my house retrofitted to help it withstand the inevitable next really big one that is coming because of what I have learned about it (I am also well above the tsunami flood zone). Subduction zones are crazy powerful but it looks like we are finally starting to learn important things about them. The challenge though is getting people to accept that they are real and will happen and entire cities need to move because of them (I'm looking at you Ocean Shores).

Side note, any actual geologists in the room? The recent Philippians 7.6 looks like it may be following a growing pattern of megathrust forshocks to my -deeply- untrained eye. Does someone with actual knowledge and training have a take on that?

VoidWarranty|4 months ago

Got any recs for contractors in the area to do the work?

What should I get done? (ranch 2 story built in 90s). Cost to expect? Been having bad luck lately with bids and sketch contractors. Takes a lot of effort to sift through.

ogogmad|4 months ago

Sea wall?