Spatial and temporal variability of glacial deposits on the western margin of Bellingshausen Dome, King George Island, South Shetland

Lic. Raúl Ugalde Peralta, Facultad de Ciencias

In the last three decades the world has been continuously discussing two ideas related to the environment: climate change and global warming. Both are the product of successive interactions between science and society as a whole. For each inhabitant of the planet, a good characterization of these two ideas will be relevant in the present and near future, because in one way or another it will affect. Scientific research seeks to understand and describe both ideas, answering the following questions: Has the climate changed as we know it? If so, how has the planet’s climate changed and will change?

Taking into account these questions, it is necessary to identify where possible climatic variations can be studied. And that’s where the importance of glaciers lies. A glacier is a gigantic mass of ice compacted for a long time, tens of thousands of years, which behaves almost like a living being: it is born, it feeds, it grows, it moves, it ages and it disappears. As it lasts a long time and continuously captures water and air in the form of snow, compacting slowly in the process, they are excellent for storing the weather information of the moment. The sensitivity of ice to changes in temperature is another feature that helps. In addition, glaciers tend to flow very slowly due to gravity, but on larger time scales that movement can be quite considerable. Geologists study the traces of the passage of glaciers over the landscape: sediment deposits, rock marks or “glacial streaks”, channels of ice melt, glacial lakes, among others. Knowing who the tracks are and when they were made, you can estimate when the glacier passed by a certain place, and how big it was.

Antarctica is a continent so remote, it has not been so affected by the impact of man. And it is almost completely covered with glaciers, so it is ideal to do studies of how these have varied. Moreover, the Artigas Station of Uruguay is right in front of a huge frozen body, the Bellingshausen Dome.

This project tries to decipher how this glacier has changed in large scale of time (thousands to hundreds of years), from the deposits that it was leaving when moving. To do this, the shapes of the relief, or “geoforms”, associated with the glacier are identified, and the time span is estimated by three techniques: in the laboratory it is calculated how long certain minerals are hidden in the sun – ‘luminescence’ – and how long the rocks have been exposed to the atmosphere; In surface it is observed how much the lichens that have lived on the rock have grown -‘lichenometry’-, because this represents the minimum time in which the deposit has not been disturbed. The sum of all that information will give you a better idea of ​​how the Bellingshausen Dome has changed, whether it has grown, advanced or receded, and in what range. The correlation with other studies will leave insights on what climatic changes could have affected over time, both on other islands in the South Shetland archipelago and across the Antarctic continent, and even on a planetary level.