For the first time ever, scientists at the University of California, Santa Cruz have measured geothermal heating under the West Antarctic ice sheet. Researchers found that the amount of heat flowing from geothermal sources deep within the Earth toward the base of the West Antarctic ice sheet was “surprisingly high.” Findings of the study were published in the latest issue of the journal Science Advances.
Geothermal heating causes melting of basal ice
Researchers led by Andrew Fisher of the UC Santa Cruz used a special thermal probe to measure temperatures in sediments below Subglacial Lake Whillans, which lies underneath half a mile of ice. The probe measured temperatures at different depths, which revealed a change in temperature. Results show a rapid flow of geothermal heat towards the bottom of the West Antarctic ice sheet.
This heating leads to melting of basal ice, which supplies water to a number of subglacial lakes and wetlands. Slawek Tulaczyk, the co-author of the study, said the geothermal heat flux was an important value for computer simulations researchers are using to understand why and how rapidly the West Antarctic ice sheet is shrinking. The geothermal heat flux will also help predict how the West Antarctic ice sheet will behave in the future.
West Antarctic ice sheet subject to a lot of studies
However, lead author Andrew Fisher emphasized that geothermal heating reported in this study doesn’t explain the huge loss of ice from West Antarctica as reported by other scientists. The West Antarctic ice sheet is part of the Antarctic ice cap, which is believed to be most vulnerable to melting. That’s why it has been investigated more than other parts as concerns over global warming and sea-level rise mount.
Fisher said the measurements were recorded only from one location beneath the ice sheet. The heat flux may vary from place to place. He added that geothermal heat flow beneath the West Antarctic sheet may also help explain why parts of the ice sheet flow rapidly as ice streams.
