Fluctuations of Heard Island Glaciers between 1947-2014

Heard Island glacier have been of interest since the island was first occupied. The fluctuations of these glaciers have previously been discussed by Budd and Stephenson (1970), Allison and Keage (1986), Budd (2000), Ruddell (2006), Donoghue (2009), and Cogley et al (2014). This is an initial report on the changes of Brown and Stephenson glaciers with a more detailed report to follow once orthorectified satellite images become available for analysis. This report examines two newly acquired sets of satellite images from 2012 and 2014. What is unique about these images is that in both sequences the images are near cloud free and include the entire island. This is unusual for this persistently cloud covered, mountainous island located in the ‘Furious Fifties’. These images provide the first chance to complete a full inventory of the island's glaciers over both years from a single day - 2 February in 2012 and 6 February in 2014. Complete satellite inventories of the island have only previously been attempted in 1988 and 2008 - in each case this required the use of images over several years and from different sources to capture the entire island. This report also includes an inventory of additional data sets and data resources that have been used to calculate the length and areas of heard Island between 1947 and 2014.

赫德岛冰川自该岛首次被科考进驻以来便备受学界关注。此前，Budd与Stephenson（1970）、Allison与Keage（1986）、Budd（2000）、Ruddell（2006）、Donoghue（2009）以及Cogley等人（2014）已就这些冰川的进退波动展开过相关讨论。本报告是针对布朗冰川与斯蒂芬森冰川变化的初步研究成果，待获取足够正射校正卫星影像（orthorectified satellite images）用于分析后，将发布更为详尽的后续研究报告。本次报告分析了2012年与2014年新获取的两组卫星影像，其独特之处在于两个时相的影像均近乎无云且完整覆盖全岛范围。对于这片地处「狂暴五十度（Furious Fifties）」海域、常年被云层笼罩的多山岛屿而言，这种近乎无云且全覆盖的影像实属罕见。此次影像为我们提供了首次契机，可基于单日成像的影像完成2012年2月2日与2014年2月6日两个时相的全岛冰川完整编目（inventory）。此前仅在1988年与2008年尝试开展该岛的完整卫星冰川编目，两次均需耗时数年、整合多源影像才能实现全岛覆盖。本报告同时收录了1947年至2014年间用于测算赫德岛冰川长度与面积的各类数据集及数据资源清单。