已收录 273188 条政策
 政策提纲
  • 暂无提纲
A surge of Perseibreen, Svalbard, examined using aerial photography and ASTER high resolution satellite imagery
[摘要] The identification of surge activity is important in assessing the duration of the active and quiescent phases of the surge cycle of Svalbard glaciers. Satellite and aerial photographic images are used to identify and describe the form and flow of Perseibreen, a valley glacier of 59 km2 on the east coast of Spitsbergen. Heavy surface crevassing and a steep ice front, indicative of surge activity, were first observed on Perseibreen in April 2002. Examination of high resolution (15 m) Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery confirmed this surge activity. Perseibreen retreated by almost 750 m between 1961 and 1990. Between 1990 and the summer of 2000, Perseibreen switched from retreat and its front began to advance. Rapid advance was underway during the period June 2000 to May 2001, with terminus advance at over 400 m yr-1. Between May and August 2001 the rate increased to over 750 m yr-1. The observed crevasse orientation indicates that ice was in longitudina...
[发布日期]  [发布机构] 
[效力级别]  [学科分类] 自然科学(综合)
[关键词]  [时效性] 
   浏览次数:2      统一登录查看全文      激活码登录查看全文