<
https://www.nytimes.com/2024/01/06/magazine/glacier-engineering-sea-level-rise.html>
"One day in 2016, a British glaciologist named John Moore attended a meeting in
Cambridge, England, that included a presentation about a glacier on Greenland’s
west coast. Typically referred to by its Danish name, Jakobshavn, but also
known by its Greenlandic moniker, Sermeq Kujalleq, the glacier functions as a
kind of drain, situated on the edge of Greenland’s massive ice sheet, that
moves 30 billion to 50 billion tons of icebergs off the island every year.
These icebergs, some of them skyscraper-size, calve regularly from the glacier
front, crash into a deep fiord and float west into Disko Bay. Then they drift
out into the North Atlantic, break apart and melt. The intense activity here,
as well its breathtaking location, have earned the area a designation as a
UNESCO World Heritage site and made it a powerful attraction for Greenland’s
small but vibrant tourist trade.
For scientists, though, Jakobshavn elicits urgency. Glaciologists have
identified it as one of the fastest-deteriorating glaciers in the world. And as
waves lap higher on the shores of cities like Miami Beach and New York, this
far-off ice is partly the reason. Jakobshavn alone was responsible for 4
percent of the rise in global sea levels during the 20th century. It probably
contains enough ice to ultimately push sea levels up at least another foot.
What struck Moore that day in Cambridge was not only Jakobshavn’s potential
collapse but also the way its ice interacts with the surrounding water. A slide
at the meeting showed how warm water nearly a thousand feet below the surface
flows from the Atlantic into Disko Bay and eventually makes its way into the
fiord and to the glacier front, where it carves away at and weakens the ice.
Moore noted something interesting at the bottom of the bay’s entrance: the warm
water flows over a sill, a ridge rising several hundred feet above the ocean
floor and just over three miles long, akin to a threshold that crosses the
floor of a doorway between two rooms. “It’s kind of a pity that sill isn’t just
a bit higher,” Moore thought. “Because then it would stop the warm water from
coming in and hitting the glacier.” Not long after, he wondered: What if
someone made the sill higher?
For the next year, Moore mulled over that question. How hard would that be? How
expensive? And how effectively could a raised sill halt the influx of warm
water and slow Jakobshavn’s shrinkage?"
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
