Applications of geophysical techniques for the analysis of the internal structure and understanding of the hydrological system of the Kinzl Covered Glacier, Cordillera Blanca, Peru

The Cordillera Blanca is currently home to 384 covered glaciers, which constitutes 46.5 % of the total of 825 covered glaciers registered in the 20 glacier ranges of Peru, according to data provided by the Glacier Inventory 2023 (INAIGEM, 2023). Therefore, in the framework of climate fluctuations driven by global warming, covered glaciers stand out as crucial elements, as their level of thawing is much slower in response to climate variability and in contrast to their debris- free glacier counterparts. This characteristic consolidates them as increasingly essential and valuable water resources.

The objective of the study is to determine the physical characteristics of the Kinzl Covered Glacier, located in the Cordillera Blanca, by applying the geophysical methods of ground penetrating radar (GPR) and vertical electrical sounding (VES). The methodology employed includes georadar profiling and point soundings to understand the composition and distribution of materials and the physical properties of the glacier. From the detailed analysis of electrical soundings and georadar profiles, a correlation of both methods has been achieved through the resistivities obtained and established for similar environments, with phases of reflected signals coming from the contours of the interfaces identified in the radargrams analysed and interpreted. This correlation has provided us with a comprehensive understanding of the internal characteristics of the Kinzl Covered Glacier, where three horizons have been identified: The first horizon composed of variable surface debris, ranging from 2 to 9 metres thick, with resistivities that remain above 16k Ohm.m; the second horizon composed of massive ice with debris, fluctuating between 40k and 300k Ohm.m and with thicknesses ranging from 40-60 metres, parallel to this horizon we also have massive ice corroborated by values of 400k and 6000k Ohm.m with thicknesses exceeding 60 metres and below this we have a third horizon composed of bedrock with average resistivity between 1.2k and 9k Ohm.m. These data found in the Kinzl Covered Glacier fit with those frequently found in glacial-periglacial deposits in the Andes.

The results provide a comprehensive understanding of the internal characteristics of the Kinzl Covered Glacier, highlighting its relevance for understanding the complexity and implications for glacial dynamics. These findings are valuable for numerical modelling, glacier risk management and water resource management.