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Rising sea destroys homes, erases beaches in California

42 points · 34 comments · geox

  1. Animats · · focus · HN ↗
    It's annoying for coastal areas, and a problem for beach houses, but California isn't really that vulnerable to rising sea levels. The Pacific Coast is mountainous and the ground slopes upward in short distances.

    Here's the US topo map.[1] Look at vulnerable spots, such as Malibu and Oceanside. Three blocks inland you're 20 feet above sea level. Almost all problems are on the ocean side of the Pacific Coast Highway, which was a marginal place to build anyway.

    Cliff edge erosion is an ongoing problem. That's why CALTRANS gave up on Devil's Slide as a road route and built the Tom Lantos Tunnels further inland. Small changes in sea level don't affect hundred-foot cliffs that much, though.

    The places that really suffer from rising sea level are river deltas, sitting on deposited sand just barely above sea level. In the US, New Orleans has the worst problem. New York City has problems, and they're building coast defenses against storms. China's coastal cities are mostly on river deltas with really flat terrain. That's why China has to build ports way off shore, reached by miles of bridges, to get to deep water.

    [1] <a href="https:&#x2F;&#x2F;en-us.topographic-map.com&#x2F;map-9t5k57&#x2F;Venice-Beach&#x2F;?center=33.18363%2C-117.36954&amp;zoom=16" rel="nofollow">https:&#x2F;&#x2F;en-us.topographic-map.com&#x2F;map-9t5k57&#x2F;Venice-Beach&#x2F;?c...

    1. gboss · · focus · HN ↗
      Isn’t the Bay Area quite vulnerable? I’m thinking they’re going to have to build a dam with locks in front of the golden gate
      1. Animats · · focus · HN ↗
        No way. The Golden Gate is really deep.

        The Bay Bridge channel is so shallow it has to be dredged. There was a 1946 plan to fill it in.[1] There were Corps of Engineers plans for a lot of filling, but they didn&#x27;t go that far. I have a copy of their 1960-2020 plan for the Bay Area.[2] Their vision was to make the SF bay area a major industrial city, building on the facilities built for WWII. Aluminum smelter in Sausalito. Steel mills at Tiberon. Five freeways up the Peninsula (101, 280, 35, 1, and one on stilts in the bay.) Another Bay Bridge. Maybe a SF-Alcatraz-Angel Island-Tiberon link. It would have been like Pittsburgh.

        [1] <a href="https:&#x2F;&#x2F;www.sfgate.com&#x2F;local&#x2F;article&#x2F;second-bay-bridge-plans-history-freeway-alameda-sf-14018498.php" rel="nofollow">https:&#x2F;&#x2F;www.sfgate.com&#x2F;local&#x2F;article&#x2F;second-bay-bridge-plans...

        [2] <a href="https:&#x2F;&#x2F;archive.org&#x2F;details&#x2F;futuredevelopmen00unit" rel="nofollow">https:&#x2F;&#x2F;archive.org&#x2F;details&#x2F;futuredevelopmen00unit

        1. cyberax · · focus · HN ↗
          This plan also resulted in a real-world scale model of the bay: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;U.S._Army_Corps_of_Engineers_Bay_Model" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;U.S._Army_Corps_of_Engineers_B...
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