The Batagai crater contains the oldest permafrost in Siberia. The permafrost is about 80% ice, which is why the slope has collapsed. Global warming has increased the size of the crater, increasing the area of the collapse to 0.8 square kilometres, making it the largest on the planet. The height of the rock at the top of the collapse is 55 metres.
To determine the age of the permafrost, the scientists used three dating methods simultaneously. They used the technology of dating using the isotope chlorine-36, as well as luminescence dating. Unlike conventional radiocarbon dating, these methods are capable of dating between 500,000 and 1 million years ago. Studies have shown that the oldest available layers of permafrost here are about 650,000 years old. It was formed during the largest ice age in the last million years.
Only the permafrost in the Canadian Yukon is considered older. It is about 700 thousand years old. It must be said that there are not many areas of very old permafrost in Siberia, which makes the current find particularly valuable.
Preliminary studies have shown that in the history of this layer there was a period of 200 thousand years when no new permafrost appeared. Scientists cannot yet say whether this layer melted or whether no permafrost formed during this period. The second gap occurred 130,000 years ago, which is logical because scientists have long known that there was interglacial warming during this period.
This finding is important for science and the study of climate change on the planet. Permafrost is a kind of repository of information about past climate change and the environment. Scientists believe that analysing this information will help them predict future climate change more accurately and take appropriate action.
По материалам: http://www.planet-today.com/2023/06/what-have-scientists-discovered-in.html