Timelapse photos of Johns Hopkins Inlet iceberg habitat, Glacier Bay National Park, Alaska, 2021

Camera image are available at: https://arcticdata.io/data/10.18739/A2W08WH8M Tidewater glacier fjords are highly dynamic environments that are affected by several glaciological and oceanographic processes: (i) subglacial discharge creates upwelling plumes that drive estuarine circulation and promote submarine melting of glaciers and icebergs, (ii) iceberg calving, which is affected by submarine melting, is a stochastic energy source that mixes near-glacier waters and produces waves that crash on shore and cause icebergs to capsize, and (iii) motion of icebergs and fjord waters are affected by winds, tides, and subglacial discharge. Numerous species reside in tidewater glacier fjords, including harbor seals, which seasonally aggregate in fjords and use ice habitat for critical life functions including pupping, molting, and foraging. Seals that haul-out on icebergs during the pupping and molting seasons take longer and deeper dives for feeding than those that use terrestrial haul-outs, but may acquire higher quality food. Additionally, icebergs do not flood during high tide, which increases the amount of time that seals can remain hauled-out and that pups can spend nursing, thus increasing energetic intake. Many basic questions remain unanswered, and the energy costs of coping with a constantly evolving landscape are unknown. This project addresses these deficiencies by investigating the temporal and spatial variability of seal habitat in Johns Hopkins Inlet, Glacier Bay, by synthesizing aerial surveys with high-rate time-lapse photogrammetry. This dataset consists of high-rate (1 photo per minute) time-lapse photos of Johns Hopkins Inlet that were acquired in summer 2021 and RINEX files from GNSS surveys of the camera tripods.

相关相机影像可获取于：https://arcticdata.io/data/10.18739/A2W08WH8M
潮汐冰川峡湾是高度动态的环境，受多种冰川学与海洋学过程共同影响：
(i) 冰下径流会形成上升羽流，驱动河口环流并促进冰川与冰山的海底消融；
(ii) 受海底消融影响的冰山崩解是一种随机能量源，可混合近冰川水域并产生拍击海岸的波浪，引发冰山倾覆；
(iii) 冰山与峡湾水体的运动受风、潮汐及冰下径流影响。

潮汐冰川峡湾内栖息着众多物种，其中港海豹会季节性聚集于峡湾，并利用冰生境完成产仔、换毛与觅食等关键生命活动。在产仔与换毛季依附于冰山休憩的海豹，相较于依赖陆地休憩点的个体，会进行更长时间、更深深度的觅食潜水，但可能获取到品质更高的食物。此外，高潮位时冰山不会被海水淹没，这延长了海豹可停留休憩的时长，也让幼崽能拥有更长的哺乳时间，进而提升能量摄入。

目前仍有诸多基础问题尚未得到解答，而应对持续变化的环境所需的能量消耗也尚不明确。本项目通过整合航空调查与高速延时摄影测量技术，对冰川湾约翰霍普金斯湾内海豹栖息地的时空变化特征展开研究，以弥补上述研究空白。

本数据集包含2021年夏季拍摄的约翰霍普金斯湾高速延时影像（拍摄频率为每分钟1张），以及相机三脚架全球导航卫星系统（GNSS）测量得到的RINEX文件。