Measurements conducted on the northeastern part of the island show that Greenland’s major glacier is rapidly shedding ice. If the Zachariae Isstrom glacier completely vanishes it could trigger a 20 inch rise of world oceans, scientists warned.
The good news is that the melting is happening extremely quickly on a geological scale. So, it may take several generations of people before the glacier melts away completely. Yet, we should expect a sea-level rise around the world in the next decades.
Study authors explained that the extremely warm weather conditions in 2012 forced the ice sheet to retreat at an alarming rate along a marine bed. Scientists said that the speed at which the sheet loses ice nearly tripled, while the pace of the thinning of its base doubled.
John Paden, a glaciology expert at the University of Kansas’ Center for Remote Sensing of Ice Sheets and co-author of the study, said that the glacier won’t melt in a day or year.
“Within a few generations, ice loss could make a substantial difference in sea levels,”
he added.
Nevertheless, if we take into account all glaciers that are shedding ice currently, many people would be affected. Paden said that global sea level rose in recent history, but the changes brought in coastal regions are minor compared with what will probably happen.
Paden’s team analyzed data gathered by NASA’s Operation IceBridge and historic measurements of the Greenland’s ice sheet. Researchers explained that there are major changes in the ‘grounding line’ or the limit between the glacier’s base and the sea.
Paden explained that along that line ice sheet starts to slide and float. And calving around that limit has already began. Recently, calving boosted the rate of ice loss off the front of the ice sheet, thus, providing the sea with extra water. To date, that phenomenon is responsible for most ice loss in the Zachariae Isstrom glacier.
The research team, which included scientists from the California Institute of Technology and from the University of California Irvine, explained that the melting that causes ice to slowly reach the ocean, where it flows before completely vanishing, contributes more to rising sea-levels than surface melting of the Greenland glacier.
Moreover, a nearby glacier called Nioghalvfjersfjorden is also melting but at a slower pace than Zachariae Isstrom. The latter is set to vanish quicker because it is already on a downslope, researchers suggested. Scientists blamed rising sea temperatures and the downward slope for the acceleration observed in the glacier’s melting rate.
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