Unique ice samples were extracted in Antarctica from a depth of 3.5km by the specialists from the Russian Antarctic Expedition of the Arctic and Antarctic Research Institute(AARI). This core sample from the ice layer above Lake Vostok is more than 1 million years old and stores information about changes in the Earth's climate from the Middle Pleistocene epoch to the present day. The new data available to scientists will help to find out the nature and estimate the rate of global warming in the past, which will make it possible to predict the climate situation of the near future.
The subglacial Lake Vostok, one of the largest on Earth, was discovered at the end of the 20th century in Antarctica near the Russian station “Vostok”, after which it got its name. The estimated area of this subglacial freshwater reservoir is about 16,000 km2, the depth is more than 1,200m. For several million years, the ecosystem of Lake Vostok remained isolated from external influences under a layer of ice at a depth of about 4km. Now it is the least studied place on the planet.
“For scientists, ancient ice about 1 million years old is of the greatest interest. It was during this period that an increased concentration of CO2 could be observed in the Earth's atmosphere. And, presumably, during this period the planet had undergone a restructuring of the climate system. By studying the data on climate change stored in ice cores, scientists will be able to hypothesize about the possible causes, rates, and consequences of the transformations that have occurred, and calculate how the natural system can work in conditions of elevated CO2 levels. The global climate transformations of the past were much more serious than those that we are experiencing now. But they happened for natural reasons. In recent centuries, industry has been actively developing; humanity affects the atmosphere with production activities that aren’t always well thought through. Now, like a million years ago, climate changes are also taking place on Earth, but their speed is noticeably higher than ever before," said Aleksandr Makarov, director of the Arctic and Antarctic Research Institute.
The Pleistocene is a geological epoch that lasted from about 2.58 million to 11.7 thousand years ago. The time period from 1.25 million to 700,000 years ago is considered to be the time of the Middle Pleistocene climatic transition.
According to scientists, in the last 800 years, life on Earth has been developing within the same climate system. It involves the change of glacial and interglacial epochs with cycles of about 100,000 years. Now we live in a relatively warm period, which can be considered interglacial.
The obtained samples of Antarctic ice will be delivered to the AARI laboratories in St. Petersburg. In total, during seasonal work, ice cores with a length of about 60m were lifted from a well in the glacier above Lake Vostok.
The project is being implemented by AARI as part of the program of comprehensive research of the subglacial Lake Vostok and the Earth’s paleoclimate in the area of the Russian Antarctic station "Vostok" together with the specialists from St. Petersburg Mining University(SPMU). This season, four AARI employees worked in Antarctica, including two women, as well as eight SPMU specialists.
Drilling of the first deep well at the station “Vostok” started in January 1970 by the employees at the Arctic and Antarctic Research Institute and Mining Institute. In 1990, a project was launched to drill the fifth deep well. The first drilling that reached Lake Vostok took place on February 5, 2012, at a depth of 3769.3m. In 2022, scientists lifted samples of ancient ice about 500,000 years old from the depths of the glacier.