Post AdXuy7Rer8bUP7rOOe by EricFielding@mastodon.social
 (DIR) More posts by EricFielding@mastodon.social
 (DIR) Post #AdTaHhLIjslBZRXer2 by EricFielding@mastodon.social
       2024-01-03T15:31:04Z
       
       0 likes, 1 repeats
       
       Geospatial Information Authority of Japan (GSI)  has processed ALOS-2 synthetic aperture radar (SAR) interferograms and pixel offset maps acquired urgently after the 1 January magnitude 7.5 earthquake under the Noto Peninsula by Japan Aerospace Exploration Agency (JAXA). The maps show uplift on the north end of the peninsula around 4 meters and horizontal displacements up to 1.3 meters.https://www.gsi.go.jp/uchusokuchi/20240101noto.html
       
 (DIR) Post #AdTaHi5jxDuHtTGkEq by mike_miley@squawk.mytransponder.com
       2024-01-03T16:16:56Z
       
       0 likes, 0 repeats
       
       @EricFielding @BakerRL75  How would you classify the 4 meter movement? Is that unusually large or fairly typical?
       
 (DIR) Post #AdTaHjA1ykvvD4HgZ6 by BakerRL75@m.ai6yr.org
       2024-01-03T16:22:19Z
       
       0 likes, 0 repeats
       
       @mike_miley @EricFielding I would consider it large 😊. But when I was in Japan in ‘78-‘82 I was constantly surprised by markers on the coast saying “peninsula did not exist prior to x-date earthquake” or “on x-date these up lifts were created” and none of the dates were more than a hundred years old.
       
 (DIR) Post #AdTaHk5SXEs25B9Y4u by mike_miley@squawk.mytransponder.com
       2024-01-03T16:33:29Z
       
       0 likes, 0 repeats
       
       @BakerRL75 @EricFielding interesting. I know intellectually that earthquakes have significant vertical components, or we wouldn't have mountains, but high school in southern California left me with a lifelong association with horizontal movements.
       
 (DIR) Post #AdTaHkqFjGIiQJ2v0y by stuff@mu.zaitcev.nu
       2024-01-03T17:47:52.823798Z
       
       0 likes, 0 repeats
       
       @mike_miley @BakerRL75 @EricFielding It may have something to do with the horizontal shaking causing more damage typically. In addition, the vertical shock arrives first. Depending on how far you are from the epicenter, you may have time to dive under the table before the horizontal wave starts. Finally, in California in particular, valley sediments amplify horizontal shaking (in both SFBA and Socal).
       
 (DIR) Post #AdXuy6ZQ6nDbguU4rA by mike_miley@squawk.mytransponder.com
       2024-01-03T17:56:38Z
       
       0 likes, 0 repeats
       
       @stuff @BakerRL75 @EricFielding I wondered about the relative damage. thanks
       
 (DIR) Post #AdXuy7Rer8bUP7rOOe by EricFielding@mastodon.social
       2024-01-03T19:01:12Z
       
       0 likes, 1 repeats
       
       @mike_miley @stuff @BakerRL75 Yes, the first wave to arrive from earthquakes, P wave, has a vertical motion, the second, S wave has horizontal motion. The most damage comes from later waves called surface waves that have both vertical and horizontal motion. All earthquakes generate both P and S waves, but in different directions. Valley sediments amplify surface waves.
       
 (DIR) Post #AdXv8qQwReA6pTdi6a by BakerRL75@m.ai6yr.org
       2024-01-03T19:09:40Z
       
       0 likes, 0 repeats
       
       @EricFielding @mike_miley @stuff Thank you Dr Fielding. I learn so much from conversations like this. It gives us “citizen observers” the science behind what we’re seeing.
       
 (DIR) Post #AdXv8rKx5OxtdBqRPM by stuff@mu.zaitcev.nu
       2024-01-05T20:00:27.493916Z
       
       0 likes, 0 repeats
       
       @BakerRL75 @EricFielding @mike_miley I agree, thanks for the correction about the surface waves. Ironically enough, the only time I was in an earthquake, I was in Irkutsk and it was a 4.0 from somewhere in Mongolia. Just had some light fixtures shake and a few books jump shelves.