A unifying framework for iceberg-calving models

被引:54
作者
Amundson, Jason M. [1 ]
Truffer, Martin [1 ]
机构
[1] Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA
基金
美国海洋和大气管理局; 美国国家科学基金会;
关键词
ICE-SHELF; TIDEWATER GLACIER; LECONTE GLACIER; MASS-BALANCE; RETREAT; ALASKA; DYNAMICS; TERMINUS; COLLAPSE;
D O I
10.3189/002214310794457173
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
We propose a general framework for iceberg-calving models that can be applied to any calving margin. The framework is based on mass continuity, the assumption that calving rate and terminus velocity are not independent and the simple idea that terminus thickness following a calving event is larger than terminus thickness at the event onset. The theoretical, near steady-state analysis used to support and analyze the framework indicates that calving rate is governed, to first order, by ice thickness, thickness gradient, strain rate, mass-balance rate and backwards melting of the terminus; the analysis furthermore provides a physical explanation for a previously derived empirical relationship for ice-shelf calving (Alley and others, 2008). In the calving framework the pre- and post-calving terminus thicknesses are given by two unknown but related functions. The functions can vary independently of changes in glacier flow and geometry, and can therefore account for variations in calving behavior due to external forcings and/or self-sustaining calving processes (positive feedbacks). Although the calving framework does not constitute a complete calving model, any thickness-based calving criterion can easily be incorporated into the framework. The framework should be viewed as a guide for future attempts to parameterize calving.
引用
收藏
页码:822 / 830
页数:9
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