南极 Getz F 冰架表面冰流速及结构特征时空变化分析

Iceberg calving and basal melting are the main component of mass loss of Antarctic ice shelves, which are closely related to climate warming. In particular, the Getz ice shelf is more sensitive to climate warming than the other ice shelves in the Amundsen sea sector. Long-term time series analysis of ice flow velocity and structural features over ice shelves is significant for understanding the evolving dynamics of ice shelves in the context of global climate change. Based on the Landsat series of images, this study used a multi-scale semi-automated image matching algorithm to derive the ice velocity measurements over the Getz F ice shelf from 2000 to 2017. We also extracted the structural features on the Getz F ice shelf in 2000 and 2017 via image enhancement and manual delineation. The results indicate that, the fast flow area(850~950 m∙a^-1)was gradually shifted to the west from 2000 to 2017, and the flow velocity generally decreased with the increase of surface elevation. The number of ice fractures in the lower and middle reaches of the ice shelf has increased significantly, and the fractures showed a trend of moving from the upper reaches to the lower reaches in the east. The flow of Getz F ice shelf is mostly fed by the Berry Glacier, the flow velocity is affected by the Modified Circumpolar Deep Water, and the front margin of the Getz F ice shelf has shown great instability.