SGER: Columbia Glacier Photogrametry

Pfeffer0228223这项提案是作为探索性研究小额拨款(SGER)提交的，目的是证明阿拉斯加东南部的哥伦比亚冰川通过快速崩解继续消退。冰川目前正以每年约0.74公里的速度退缩。伴随着这种快速退缩的是每天33米的水流速度，使其成为世界上移动最快的冰川。自1982年以来，自18世纪中叶以来，冰川末端已经后退了13多公里。它向威廉王子湾排放的冰超过22千米。随着冰川末端穿过一个限制其流动的缝隙，明年冰川的模式和退缩速度可能会发生重大变化。未来几个月的活动可能会为哥伦比亚冰川的长期命运提供重要线索，因为冰川退缩将沿着冰川床位于海平面以下的海峡向上推进。首席调查员正在继续分析1999年、2000年和2001年的摄影测量数据，并将于2002年8月向OPP/ANS提交一份建议。然而，目前冰川末端的位置和新计算的冰下地形可能意味着冰川处于退缩的临界状态，重大事件可能在2002年底之前发生。这笔资金将允许他们在2002年继续进行航空摄影，届时航站楼进入更深的水域并通过一个主要的侧向收缩可能会发生重要的变化。

Pfeffer0228223This proposal was submitted as a Small Grant for Exploratory Research (SGER) to document to continuing retreat of the Columbia Glacier, in southeast Alaska by rapid calving. The Glacier is presently retreating at a rate of approximately .74 kilometers (km) per year. This rapid retreat has been accompanied by flow speeds up to 33 meters (m) per day, making it the world's fastest-moving glacier. Since 1982, the glacier terminus has retreated more than 13 km since the mid-eighteenth century. It discharges ice into Prince William Sound in excess of 22 km3 . Significant changes may be occurring in the glacier's pattern and speed of retreat during the next year as the glacier terminus passes through a gap which confines its flow. The activities over the next few months may provide important clues about the longer-term fate of Columbia Glacier as the retreat progresses up the channel where the glacier bed lies below sea-level. The Principal Investigators are continuing their analysis of photogrammetric data from 1999, 2000, and 2001 and will submit a proposal to OPP/ANS in August 2002. However, the present terminus position and newly calculated subglacial topography may mean that that the glacier is at a critical state in its retreat, and that significant events may occur before the end of 2002. The funds will allow them to continue the aerial photography through 2002 when important changes may occur as the terminus enters deeper water and passes a major lateral constriction.