| Summary: | Objective The objective of this project is to establish that non–invasive subsurface imaging with ground penetrating radar (GPR) is a viable method to map internal structure of artificial ice reservoirs(AIR) and to estimate volume. Particular objectives were the following: Volume validation : GPR surveys could be used tovalidate volumes of AIRs. Spatial density resolution : GPR data could help identify air, snow and ice layers within the AIR. GPR Field Work GPR survey has been conducted on four Ice Stupas at locations namely Phaterak, Gangles, Kullum and Takmachik in March 2020 as part of an Swiss Polar Institute fundedexpedition . Why Ground Penetrating Radar? Ice is very transparent to GPR signals, allowing tremendous penetration. GPR is also sensitive to subtle changes in the properties of ice layers. This makes it a powerful tool to image the internal structure of glaciers and ice sheets at a scale of meters or hundreds of meters. The basic principle of a pulsed GPR system is to send an electromagnetic signal into the ground and to record the signal reflections as a function of their two-way travel time. Partial reflections of the electromagnetic wave recorded as internal reflection horizons (IRH) occur at vertical discontinuities in the dielectric material. From polar studies, IRH are known to coincide with variations in density, acidity (Robin et al., 1969), liquid water content (Forster et al., 2014) and changes in crystal orientation fabric. Archive contents The archives contents are organized in four separate directories. Each directory contains GPR data of one icestupa. Apart from this, a preliminary report is also attached produced by the GPR company (SHIJAY PROJECTS).
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