St Petersburg University scientists: Antarctic englacial lake will degrade by a quarter in the next five years
Hydrologists from St Petersburg University have modelled scenarios for the development of Antarctic englacial Lake Dålk, which caused a catastrophic outburst in the Antarctic glacier in 2018. The scientists concluded that an increase in the temperature of the glacier, within which the lake is located, will lead to the fact that in the next five years it will freeze to a depth of up to seven metres, which is just under a quarter of its original depth.
Lake Dålk is an Antarctic englacial water body that has never broken up during the entire period of studies of this area. The lake is located in East Antarctica near the Russian Progress-1 field base. It lies within the thickness of the glacier and has been covered by a layer of ice several metres thick for at least half a century. The scientists also consider this lake to be a model object for studying the processes that occur in subglacial reservoirs, in particular their outbursts and the flow of water from one lake to another.
The research findings are published in Polar Science
In January 2018, there was an outburst of this lake, which led to the formation of a vast depression in the glacier. In all likelihood, climatic factors caused Lake Boulder, located higher in relation to Lake Dålk, to burst out. The scientists believe that its waters filled Lake Dålk through cracks in the glacier. Due to the difference in pressure, the ice roof over the lake could not withstand and collapsed, as a result of which the lake started to burst through the glacier. The scientists believe that the outburst of Lake Dålk was caused by an external impact. In particular, due to the movement and warming of the glacier. This is because an increase in glacier temperature leads to a decrease in the viscosity of the glacier, and, as a result, an increase in the speed of its movement due to spreading. This, in turn, leads to faster glacier movement. Global warming of the external environment has also played its role, resulting in accelerated melting of the near-surface layer in the warm period.
Two types of modelling were performed. The first one is for model verification, i.e. for comparison of model calculations with the results of field studies. In this case, the input parameters of modelling were meteorological data from the Progress station. In the second case, the process of possible development of Lake Dålk for the next five years was modelled.
Sergey Popov, Associate Professor in the Department of Land Hydrology at St Petersburg University
‘The modelling results fully coincided with the results of in-situ observations during the field work. This means that the model we used is reliable,’ said Sergey Popov, Associate Professor in the Department of Land Hydrology at St Petersburg University.
The research is supported by a grant from the Russian Science Foundation (project No 22 27 00266).
The scientists modelled three possible scenarios for the development of the lake. For this purpose, they used climatic data for every day between 2012 and 2023. In the first scenario, the thickness of the snow cover will not change. In the second scenario, it will increase evenly, with the same dynamics as in the last two years. In the third scenario, the thickness of the snow cover will increase significantly.
Apart from a few details, all three scenarios point to one common trend — the degradation of Lake Dålk. Over the next five years, the lake could freeze to a depth of six to seven metres, depending on the scenario. This is just under a quarter of its original depth.
St Petersburg University, the oldest university in Russia was founded on 28 January (8 February) 1724. This is the day when Peter the Great issued a decree establishing the University and the Russian Academy of Sciences. Today, St Petersburg University is an internationally recognised centre for education, research and culture. In 2024, St Petersburg University will celebrate its 300th anniversary.
The plan of events during the celebration of the anniversary of the University was approved at the meeting of the Organising Committee for the celebration of St Petersburg University’s 300th anniversary. The meeting was chaired by Dmitry Chernyshenko, Deputy Prime Minister of the Russian Federation. Among the events are: the naming of a minor planet in honour of St Petersburg University; the issuance of bank cards with a special design; the creation of postage stamps dedicated to the history of the oldest university in Russia; and the branding of the aircraft of the Rossiya Airlines to name just a few. Additionally, the University has launched a website dedicated to the upcoming holiday. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of preparations for the anniversary.