Investigations of long-term and seasonal scale variations of flow velocity and frontal position of outlet glaciers in Greenland utilizing multi-temporal Landsat imagery

利用多时相 Landsat 图像研究格陵兰岛冰川出口流速和锋面位置的长期和季节性尺度变化

基本信息

批准号：
258481807
负责人：
Professor Dr.-Ing. Martin Horwath, since 11/2015
金额：
--
依托单位：
Professur für Geodätische Erdsystemforschung
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/258481807?language=en
关键词：
Investigations long term seasonal scale

项目摘要

For more than a decade, the cryosphere with its glacier regions have been affected by large changes. Many of the outlet glaciers of the Greenland Ice Sheet currently show accelerated flow velocities and a significant surface lowering while sustaining a substantial retreat. In particular, marine-terminating glaciers show a dynamic behavior which is not included in current predictions of the future sea-level change. Thus, the marine-terminating outlet glaciers and their influencing factors at the ice-ocean-boundary are the major research object within the proposal. In the time period between 1972 and 2012 flow velocity fields are available for more than 300 outlet glaciers along the margin of the Greenland Ice Sheet. In addition, information about the frontal position as well as their temporal changes are available for more than 100 glaciers. Within the project term both flow velocity and frontal positions of the glaciers are to be extended using satellite data of Landsat7 and Landsat8. Moreover, satellite data of the Sentinel mission expected to start in 2012 will be incorporated. Long-term and seasonal scale variations of flow velocity and the position of the glacier front as well as their interrelation will be investigated using this large data archive. Special focus will be given on the dynamic processes acting at the ice-ocean boundary. This includes the investigation of the impact of the ice mélange in the proglacial fjord on the stability of the frontal position and on the flow velocity. To analyze regional patterns of synchronous glacier changes information about both the annual cycle of sea-ice formation and sea-surface temperatures derived from MODIS data will be incorporated. In the area of North and Northeast Greenland the long-term evolution of the flow velocity as well as changes of the terminus position for more than four decades will be studied. In particular, the effect of observed long-term changes of the sea ice and fast ice formation on the stability of the glacier front accompanied by an ice shelf will be investigated. All available flow-velocity fields will be used to identify surge events of outlet glaciers and their relation to changes of the frontal position and to changes of the spatial-temporal variability of the flow regime.

十多年来，具有冰川区域的冷冻圈受到了巨大变化的影响。格陵兰冰盖的许多出口冰川目前都表现出加速的流速和显着的表面降低，同时维持了大量撤退。特别是，海洋末端冰川显示出一种动态行为，这不包括在未来海平面变化的当前预测中。这是该提案中的主要研究对象。在1972年至2012年之间的流速场之间，沿格陵兰冰盖边缘有300多个出口冰川。此外，有关额叶位置及其临时变化的信息可用于100多个冰川。在项目术语中，冰川的流速和额叶位置都应使用Landsat7和LandSAT8的卫星数据扩展。此外，预计将于2012年开始的哨兵任务的卫星数据将合并。流速的长期和季节性尺度变化以及冰川前沿的位置以及它们的相互关系将使用此大数据存档进行研究。将特别重点放在作用于冰山边界的动态过程。这包括对程序峡湾对额叶位置和流速稳定性的影响的投资。为了分析同步冰川的区域模式，将纳入有关海冰形成的年度周期和从MODIS数据中获得的海面温度的信息。在格陵兰北部和东北部的地区，流速度的长期演变以及末端位置的变化将在四十多年内进行研究。特别是，将研究观察到的海冰和快速冰形成对冰架完成的冰川前部稳定性的长期变化的影响。所有可用的流速度场将用于识别出口冰川的涌现事件及其与额叶位置的变化以及流动状态的时空变异性变化的关系。