权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Linking micro-physical properties to macro features in ice sheets with geophysical techniques

利用地球物理技术将冰盖的微观物理特性与宏观特征联系起来

基本信息

批准号：
52220176
负责人：
Professor Dr. Olaf Eisen
金额：
--
依托单位：
Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
依托单位国家：
德国
项目类别：
Independent Junior Research Groups
财政年份：
2007
资助国家：
德国
起止时间：
2006-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/52220176?language=en
关键词：
Linking micro physical properties macro

项目摘要

The flow of the Antarctic ice sheet is controlled by processes occurring at its surface, at its base, and by the spatial variation of rheological properties within the ice.The internal structure of the ice sheet represents an integrated memory of the interaction of these processes and properties, knowledge of which has key implications for unraveling its history and predicting its future behaviour.The proposed young research group engages in the detection of macro-scale internal layer architecture with electromagnetic and seismic reflection methods, and the understanding of physical properties on the micro-scale which cause the reflections.Laterally imaging the layer architecture yields complementary information to the direct evidence of physical properties otherwise solely provided by ice cores, which are however limited to single points.The frequency-dependent dielectric properties of firn and ice cores in the range of 100 kHz to 3 GHz are determined with a large coaxial cell.Seismic properties and the possibility to image these by surface experiments are investigated during field studies in the European Alps and in Antarctica.The combination with physical ice-core properties enables forward modeling of seismograms and identification of seismic reflector origins.Development of an inversion scheme yields the means to extract the micro-physical information inherent in electromagnetic and seismic data and to provide a distribution of physical properties in the ice column.

南极冰盖的流动受其表面和底部的过程以及冰内流变特性的空间变化所控制。冰盖的内部结构代表了这些过程和特性相互作用的综合记忆，了解这些知识对于解开它的历史和预测它的未来行为具有关键意义。拟议中的年轻研究小组从事用电磁和地震反射方法探测宏观尺度的内部层结构，并了解引起反射的微观尺度上的物理特性。对层结构进行横向成像可产生补充信息，以提供物理特性的直接证据，否则只能由冰芯提供，然而，其仅限于单点。频率-在100 kHz至3 GHz的范围内，用大型同轴电池测定了积雪和冰芯的相关介电特性。在欧洲阿尔卑斯山和南极洲的实地研究期间，研究了通过地面实验对这些进行成像的方法。结合冰芯的物理特性，可以对地震图进行正演模拟，并识别地震反射体的起源。