Researchers from the Massachusetts Institute for Technology have shown that the material strength and fracture toughness of ice are decreased significantly under increasing concentrations of CO2 molecules, making ice caps and glaciers more vulnerable to cracking and splitting into pieces, as was seen recently when a huge crack in the Pine Island Glacier in Antarctica spawned a glacier the size of Berlin.
Ice caps and glaciers cover seven per cent of the Earth—more than Europe and North America combined—and are responsible for reflecting 80 per cent of the Sun's light rays that enter our atmosphere and maintain the Earth's temperature. They are also a natural carbon sink, capturing a large amount of CO2.
"If ice caps and glaciers were to continue to crack and break into pieces, their surface area that is exposed to air would be significantly increased, which could lead to accelerated melting and much reduced coverage area on the Earth. The consequences of these changes remain to be explored by the experts, but they might contribute to changes of the global climate," said lead author of the study Professor Markus Buehler.
...Notably, the decreased ice strength is not merely caused by material defects induced by CO2 bubbles, but rather by the fact that the strength of hydrogen bonds—the chemical bonds between water molecules in an ice crystal—is decreased under increasing concentrations of CO2. This is because the added CO2 competes with the water molecules connected in the ice crystal...
A rift in the Pine Island Glacier in Antarctica, shot by NASA
No comments:
Post a Comment