近日，研究人員在12月在線出版的Nature Geoscience期刊上發(fā)表報(bào)告"Rapid response of Helheim Glacier in Greenland to climate variability over the past century"稱,，自從1890年以來,，格陵蘭島黑爾海姆冰川的冰裂速度首次達(dá)到目前的水平。
這項(xiàng)研究發(fā)現(xiàn)表明,，盡管在冰山裂解過程中冰釋放的速度有很大的波動(dòng)性,，但目前觀察到的冰川裂解活動(dòng)是非同尋常的高,。
在格陵蘭島，利用采集自峽灣的沉積巖心,，Camilla Andresen和同事重建了從黑爾海姆冰川到塞爾米利克峽灣的冰山崩解速度,。他們發(fā)現(xiàn)每年的沙粒沉積量有很大變化，表明冰山裂解也有很大的波動(dòng)性,。然而,，目前的裂解速度之高破了紀(jì)錄，類似的活動(dòng)之前只在20世紀(jì)30年代發(fā)生過一次,。（生物谷Bioon.com）
doi:10.1038/ngeo1349
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PMID:
Rapid response of Helheim Glacier in Greenland to climate variability over the past century
Camilla S. Andresen,Fiammetta Straneo,Mads Hvid Ribergaard,Anders A. Bj rk,Thorbj rn J. Andersen,Antoon Kuijpers,Niels N?rgaard-Pedersen,et al.
During the early 2000s the Greenland Ice Sheet experienced the largest ice-mass loss of the instrumental record1, largely as a result of the acceleration, thinning and retreat of large outlet glaciers in West and southeast Greenland2, 3, 4, 5. The quasi-simultaneous change in the glaciers suggests a common climate forcing. Increasing air6 and ocean7, 8 temperatures have been indicated as potential triggers. Here, we present a record of calving activity of Helheim Glacier, East Greenland, that extends back to about AD 1890, based on an analysis of sedimentary deposits from Sermilik Fjord, where Helheim Glacier terminates. Specifically, we use the annual deposition of sand grains as a proxy for iceberg discharge. Our record reveals large fluctuations in calving rates, but the present high rate was reproduced only in the 1930s. A comparison with climate indices indicates that high calving activity coincides with a relatively strong influence of Atlantic water and a lower influence of polar water on the shelf off Greenland, as well as with warm summers and the negative phase of the North Atlantic Oscillation. Our analysis provides evidence that Helheim Glacier responds to short-term fluctuations of large-scale oceanic and atmospheric conditions, on timescales of 3–10 years
