It is common to observe rivers on the surface of glaciers. These feed on surface melting and are constantly changing. These changes are due to the sunlight melting the ice around the river and, to a certain extent, the river bed since the waters are transparent. Simultaneously, rain and warm air cause the melting of the ice surrounding the river, and the flow of water causes the melting of its bed. It is not yet known how all these factors interact, resulting in some cases in supraglacial river beds that stay stable near the surface level, and in other cases, river beds deeply incised into the ice.
These questions gained renewed interest after the 2021 drainage of Cachet II Lake in the Northern Patagonian Icefield. Unlike previous drainage events, the 2021 drainage did not evacuate the water under the glacier but rather on top of the glacier due to the runaway growth of a supraglacial river.
This project seeks to understand the factors that influence the deepening of supraglacial rivers to determine what conditions must exist for drainage events (GLOF), such as the 2021 event on Lake Cachet II.

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Project's objectives

• Measure the rate of subaerial ablation around supraglacial rivers.

• Measure the rate of underwater ablation in the bed of supraglacial rivers with and without the influence of solar radiation.

• Determine what fraction of the energy dissipated by the flow of water is invested in melting the bed in supraglacial rivers and under what conditions this fraction becomes dominant in the river's evolution.

Study of vertical meteorological variations

Rising temperatures are one of the factors contributing to the retreat of glaciers. However, the increase in temperature is not equal at different altitudes. Therefore, it may affect different areas of the glacier differently, or some glaciers more than others. Vertical profiles are important to see how the temperatures and winds of the meteorological models are related to those observed above and on the glacier's surface, which determine the ablation rate.
One traditional way to measure the vertical variation of temperature, wind, and other meteorological variables is by launching disposable sounding balloons. Although there are reusable versions, it is common for them to get lost, especially in mountainous terrain. Therefore, it is an expensive and polluting methodology. In this research project, we will use a technique based on UAVs and low-latency meteorological sensors built using the open hardware framework at the University of Magallanes. The UAV will be equipped with sensors capable of measuring altitude and rapid changes in temperature, humidity, and wind speed, allowing it to measure vertical weather profiles of 3,000 meters or more in just a few minutes.
In addition, the results will be compared with measurements made with professional instruments, both ground-based and designed for UAVs.

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Project's objectives

• Improve and build the low latency micro weather station used for UAVs in previous campaigns.

• Validate and calibrate measurements using multiple techniques, such as reference ground sensors, UAV drift, UAV attitude and smoke bombs.

• Measure the vertical gradient of temperature, humidity and wind over different areas on and around the glacier.

• Study the spatial and temporal variations of the different meteorological parameters observed.