PDF(Pubmed)
Abstract：
Accelerated warming since the 1950s has caused dramatic change to ice shelves and outlet glaciers on the Antarctic Peninsula. Long observational records of ice loss in Antarctica are rare but essential to accurately inform mass balance estimates of glaciers. Here, we use aerial images from 1968 to reveal glacier configurations in the Larsen B region. We use structure-from-motion photogrammetry to construct high-resolution (3.2 m at best) elevation models covering up to 91% of Jorum, Crane, Mapple, Melville and Flask Glaciers. The historical elevation models provide glacier geometries decades before the Larsen B Ice Shelf collapse in 2002, allowing the determination of pre-collapse and post-collapse elevation differences. Results confirm that these five tributary glaciers of the former Larsen B Ice Shelf were relatively stable between 1968 and 2001. However, the net surface elevation differences over grounded ice between 1968 and 2021 equate to 35.3 ± 1.2 Gt of ice loss related to dynamic changes after the ice shelf removal. Archived imagery is an underutilised resource in Antarctica and was crucial here to observe glacier geometry in high-resolution decades before significant changes to ice dynamics.
摘要：
自20世纪50年代以来，加速变暖导致南极半岛的冰架和出口冰川发生了巨大变化。南极洲冰流失的长期观测记录很少见，但对于准确告知冰川的质量平衡估计至关重要。这里,我们使用1968年的航拍图像来揭示拉森B地区的冰川构型。我们使用运动结构摄影测量法来构建高分辨率（最多3.2m）高程模型，覆盖高达91％的Jorum，起重机,马普,梅尔维尔和烧瓶冰川。历史高程模型提供了2002年LarsenB冰架塌陷前几十年的冰川几何形状，从而可以确定塌陷前和塌陷后的高程差。结果证实，前LarsenB冰架的这五个支流冰川在1968年至2001年之间相对稳定。然而,1968年至2021年之间，地面冰的净表面高程差等于35.3±1.2Gt的冰损失，与冰架清除后的动态变化有关。存档图像是南极洲未充分利用的资源，对于在冰动力学发生重大变化之前的高分辨率几十年中观察冰川几何形状至关重要。
