• Mike
    link
    fedilink
    English
    arrow-up
    4
    ·
    7 hours ago

    Sea level at geological time scale is wild. Hundreds of metres.

    I find it fascinating since we live during such a short period on the geological time scale.

    Driven mostly by glaciation effects, but thermal expansion of sea water is also significant. These effects can be partially offset in places by isostatic rebound (plates are floating, so reducing ice mass on continents allows them to rebound or rise, lowering apparent sea level, relative to the land).

    There’s a lot less ice left, since the sea level has already risen >110m since the last glacial maximum (~20000 years ago), and has been quite stable for the past ~6500 years. This stability has been influential in the placement of human settlements along coastlines and river deltas.

    Its fun that ice shelf melt doesn’t change sea level, the same way the melting ice cube in a glass of water doesn’t, but ice on land does. This is why the focus is generally on Antarctic and Greenland.

    Together, the Antarctic & Greenland ice sheet could cause almost 68m of sea level rise, converting this unsinkable aircraft carrier to more of a stationary submarine?