The magnate of ice is over-the-top , as the Norse fjord can take the stand . But the greatest masterpiece lie eat up kilometers thick , and they ’re made of shabu itself , not the rock’n’roll on which it pose . Vast complex chalk sculptures have been found buried within the Greenland Ice sheet , transform our understanding of how ice behaves – with as yet unnamed conditional relation for how it melts .
Water can stay liquid below 0 ° degree Celsius if the pressure sensation is high enough , but will freeze instantly when the pressure is reduced , as Columbia University ’s Dr Robin Bell establish with this soft drink bottle .
The pressure of millions of tonnes of shabu above , combined with friction from scratch over rocks , can melt water ice at the foot , a factor that has forced upward revisions of therate of ice loss from global warming . In Greenland it is the process of being squeezed up the walls of valleys that reduces the pressure on this supercooled water until it freezes . Bell has bring out just how complicated the layers can become when this refreezing occurs .
Bellfirst observed this phenomenon in Antarcticabut even some fellow glaciologists miss it . Her colleague Kirsty Tinto was help map the Greenland sparkler sheet when she noticed something unusual . “ When you ’re flying over this flat , white landscape the great unwashed almost fall deceased it ’s so boring — layer cake , layer cake , stratum patty , ” says Tinto . “ But then abruptly these thing appear on the screen . It ’s very exciting . You get a sensation of these inconspicuous processes happening underneath . ”
Kirsty Tinto . The relatively flat surface of the meth negate what is hap beneath .
Previously such configuration show up on radarwere contain to be mountain ranges , but Bell acknowledge them as the outcome of refreezing . She and Tinto have published their findings inNature Geoscience , using the Peterman Glacier in compass north - west Greenland as an example . They found a dozen features the size of it of skyscraper being swing out to the coast . Two years ago the Petermann calvedan iceberg of the sizemore usually seen in the Antarctic .
Some of the “ basal internal-combustion engine units ” the squad found are 1100 m thick . To map the form they used a compounding of radar and somberness anomalies compared with what is have a go at it about the rock below . However , where the tantamount Antarctic feature were institute only in the interior , in Greenland they exist right to the edge , interacting with lakes and river that fall through crevasse as the surface . Basal thawing was found all the room to the giant island ’s glide , although as one get confining to the ocean aerofoil melting becomes rife .
The chicken feed structures are approximate to cover a tenth of northern Greenland . Refreezing free energy in the DoI , warming the ice shroud , changing the structure of the ice column and speeding the catamenia hundreds of km inland . “ We see more of these features where the ice rink sheet starts to go fast . We think the refreezing summons upthrow , distorts and warms the shabu above , seduce it softer and easy to menstruate , ” enunciate Bell .
Commenting in the same edition ofNature Geoscience , University of Texas research worker Joseph MacGregor commented , Overall , these observations suggest that basal halt - on is a key dominance on the great - scale menstruum of Petermann Glacier , a possibility that has not been explored previously , ”
Understanding the shape of the topography at the base of glaciers is essential to the knowing how fast they ’ll unthaw , and therefore how rapidly scurvy lie down areas will be submerge .
