Three-dimensional internal structure and characteristics of periglacial landforms as a key to enhance the understanding of process dynamics and sensitivity to climate change

关于多年冻土赋存状态和地下特征，多年冻土环境往往表现出极大的小尺度异质性，尤其是在不连续和零星分布的多年冻土分布边缘。冰缘地貌反映了气候、地形和岩性条件，并指示了过去或现代的气候条件和地下结构。地下非均质程度及其对过程动力学的影响引起了问题。缺乏与地下成分、结构和含冰量有关的地面特征的三维信息是调查受多年冻土影响的地貌的响应及其对大气变暖的敏感性的主要问题之一。因此，该项目的中心目标是对典型的高山和亚北极冰缘地貌的内部结构和特征进行详细的三维评估，这些地貌表明冰冻的地面条件(冰川前场、岩石冰川、碎石斜坡、有图案的地面、岩浆)。由于地表和地下条件之间的复杂相互作用，不同的受多年冻土影响的地貌将对大气变暖表现出不同的响应/敏感性。因此，研究方法的基础是评估地表(地形参数、纹理、地表温度、积雪)和次表层参数(结构、霜表形状、地面冰特征、地面温度和湿度)的异质性，并将其与次表层过程和地貌过程动力学联系起来。地貌地貌的地下非均质性将通过微创三维电阻率成像的新应用来绘制。将代表性点位的现场测量和三维地下电阻率成像相结合的方法被认为是更好地了解冰缘环境关于地表和地下非均质性的关键。预期的新见解将有助于改进不同地貌的概念模型，从而有助于在不断变化的环境条件下制定高山和亚北极景观演变的情景。

Permafrost environments often exhibit a great small-scale heterogeneity concerning permafrost occurrence and subsurface characteristics especially at the fringe of discontinuous and sporadic permafrost distribution. Periglacial landforms reflect climatic, topographic and lithological conditions and are indicative for past or modern climatic conditions and subsurface structures. Questions arise concerning the degree of subsurface heterogeneity and its impact on process dynamics.The lack of three-dimensional information on ground characteristics relating to subsurface composition, structure and ice content is one of the major problems in investigating responses of permafrost-affected landforms and their sensitivity to atmospheric warming. Consequently, the central objective of the project is to achieve a detailed three-dimensional assessment of the internal structure and characteristics of typical alpine and subarctic periglacial landforms indicative for frozen ground conditions (glacier forefields, rock glaciers, scree slopes, patterned ground, lithalsas). Different permafrost-affected landforms will exhibit various response/sensitivity to atmospheric warming due to complex interactions between surface and subsurface conditions. Hence, the research approach is based on the assessment of heterogeneities in surface (terrain parameters, texture, ground surface temperatures, snow cover) and subsurface parameters (structure, frost table configuration, ground ice characteristics, ground temperature and moisture) and to correlate these with subsurface processes and geomorphic process dynamics. Subsurface heterogeneities of the geomorphic landforms will be mapped through the novel application of minimal-invasive 3D resistivity imaging.An approach combining both in-situ point measurements at representative sites and 3D subsurface resistivity imaging is thought to be the key to a better knowledge base about heterogeneous periglacial environments with regard to surface and subsurface heterogeneity. The expected new insights will help to improve conceptual models for the different landforms and hence, the development of scenarios for alpine and subarctic landscape evolution under changing environmental conditions.