Continued northward expansion of the Ross Ice Shelf, Antarctica
Continued northward expansion of the Ross Ice Shelf, Antarctica
复制标题
南极洲罗斯冰架继续向北扩张
DOI：
10.3189/1998aog27-1-93-98
复制
发表时间：
1998
影响因子：
2.9
通讯作者：
L. Brigham
中科院分区：
文献类型：
--
作者：
H. Keys;S. Jacobs;L. Brigham
最近一次沿着罗斯冰架（南极洲RIS）前缘的主要产冰事件发生在十年前，在事件发生前几年，冰前缘前进的速度大幅增加。这次“B-9”事件发生在爱德华七世半岛和罗斯福岛之间的锋面东部，移走了约5100平方公里的冰，这是该地区100年来的进步，但只减少了1%的冰架面积。自1987年以来，整个冰锋继续前进，超过了在B-9事件中失去的面积。西部战线现在位于过去150年中记录的任何位置的北部，并且至少有90年没有经历过大规模的冰解。冰锋高度一般从东向西减小，但局部变化很大。海拔从西经171°到177°相对较低，这是外部冰架下方“温暖”的修正环极深水环流的位置。现代高度大大超过179° W和178° E之间的历史高度，并在174° E以西较低，可能是由于最近的动力学变化，如裂谷和西推进。RIS锋面的总体推进以及主要产冰事件之间的几十年到世纪以上的时间与相对稳定的冰锋一致。这与南极半岛和罗斯海麦克默多冰架沿着的几个较小的冰架形成鲜明对比，这些冰架在过去几十年中大幅退缩。
The last major calving event along the Ross Ice Shelf (RIS, Antarctica) front occurred a decade ago, following a substantial increase in the rate of ice-front advance in the few years preceding the event. This “B-9” event, on the eastern part of the front between Edward VII Peninsula and Roosevelt Island, removed ≈ 5100 km2 of ice, about 100 years of advance in that sector, but reduced the ice-shelf area by only 1%. Since 1987 the entire ice front has continued to advance, more than regaining the area lost during the B-9 event. The western front is now well north of any position recorded during the last 150 years, and it lias not experienced major calving forat least 90 years. Ice-front heights generally decrease from east to west, but local variability is high. Elevations are relatively low from 171° to 177° W, the location of “warm” Modified Circumpolar Deep Water circulation beneath the outer ice shelf. Modern heights considerably exceed historical heights between 179° Wand 178° E and are lower west of 174° E, probably due to recent dynamic changes such as rifting and the western advance. The general advance of the RIS front and the period of several decades to more than a century that elapses between major calving events is consistent with a relatively stable ice front. This contrasts with several smaller ice shelves along the Antarctic Peninsula and McMurdo Ice Shelf in the Ross Sea which have retreated substantially during the past few decades.