person:joshua stevens

  • La NASA a les pieds dans l’eau…

    Sea Level Rise Hits Home at NASA
    http://earthobservatory.nasa.gov/Features/NASASeaLevel

    Watching Waters Rise Right Outside the Front Door


    The Sun rises at Kennedy Space Center. The sea is steadily doing the same.
    (Photo by NASA/Andres Adorno)

    In a review of the agency’s vulnerability to sea level rise, NASA’s Climate Adaptation Science Investigators (CASI) Working Group recently wrote:
    Sea level rise of between 13 and 69 centimeters by the 2050s is projected for NASA’s five coastal centers and facilities…Even under lower sea level rise scenarios, the coastal flood event that currently occurs on average once every 10 years is projected to occur approximately 50 percent more often by the 2050s in the Galveston/Johnson Space Center area; 2 to 3 times as often near Langley Research Center and Kennedy Space Center; and 10 times more frequently in the San Francisco Bay/Ames Research Center area. NASA coastal centers that are already at risk of flooding are virtually certain to become more vulnerable in the future.

    These maps show (in red) areas around NASA centers that would be inundated by 12 inches (30 centimeters) of sea level rise. Explore this data using NOAA’s interactive sea level rise and vulnerability tool. (NASA Earth Observatory maps by Joshua Stevens based on data from NASA’s Climate Adaptation Science Investigators Working Group)
    If you think about the height of the sea surface like the height of the water in a calm bathtub, then a rise of a few tens of centimeters over a few decades doesn’t sound like much. But sea level doesn’t rise evenly; it piles up more in some places because of natural wind and current patterns. And turbulence matters: Think about that bathtub with a child sloshing around in it. Waves can roll up one side and then the other, sometimes splashing over the brim. The higher the flat-water line, the greater the chance that the water will slosh out of the basin when it is stirred up by storms and winds.
    Sea level also matters in a horizontal direction. An old rule of thumb is that 1 inch of vertical change in sea level translates into 100 inches of horizontal beach loss on a flat beach or marsh. In this way, a little bit of sea level rise can translate into a lot of water moving inland with storms or abnormally high tides.
    Sea level is important because it gradually moves the high-tide line farther up the beach and closer to buildable land,” said John Jaeger, a coastal geologist from the University of Florida. “It also allows storm surges to penetrate farther inland.

    Launching from a Sandbar
    The high-tide line has been moving landward for some time at Kennedy Space Center on Florida’s east coast. Located within the Merritt Island National Wildlife Refuge and adjacent to Cape Canaveral Air Force Station, NASA’s most famous center covers more than 66 square miles (170 square kilometers) and holds about 20 percent of the agency’s constructed assets. Most of it is built on coastal marshland about 5 to 10 feet above sea level.


    Launch Pad 39B at Kennedy Space Center has been the site of dozens of Apollo era and space shuttle launches. Future SLS and Orion spacecraft will lift off from this site. (NASA)

    Conservative climate models project that the seas off Kennedy will rise 5 to 8 inches by the 2050s, and 9 to 15 inches by the 2080s. If ice sheets in Greenland and Antarctica continue to melt as quickly as current measurements indicate, those numbers could become 21 to 24 inches by the 2050s and 43 to 49 inches by the 2080s.

    We consider sea-level rise and climate change to be urgent,” said Nancy Bray, spaceport integration and services director for Kennedy.