6000 years ago, the alpine peaks were ice-free to the top

6000 years ago, the alpine peaks were ice-free to the top

Until 5,900 years ago, alpine peaks from 3,000 to 4,000 meters were likely ice-free, as researchers with the participation of PSI and the University of Bern discovered using ice cores. Only the highest peaks had an ice cap at the time.

The Holocene is the hot climate of the post-glacial period that has lasted for more than 11,000 years and continues to this day. Although age is considered relatively stable in earth’s history, the warmest and coldest periods alternated regionally over and over again.

To determine the ice sheet during this era in the Alps, the research team drew two ice cores from Switzerland, Austria and Italy on top of the 3,518-meter-high Weissseespitze in the Ötztal Alps. The sampling point is only twelve kilometers from the place where the mummified iron corpse Ötzi was found, whose age has been dated to about 5,300 years.

Glaciers in deeper regions in the time of Ötzi

With the help of radiocarbon dating, the team discovered that the oldest ice in the Weissseespitze, which was frozen in the rock at a depth of eleven meters, is around 5,900 years old. According to this, peaks between 3,000 and 4,000 meters were ice-free during the middle Holocene or covered by glaciers significantly smaller than today, as the researchers report in the journal Scientific Reports. Only the highest peaks had an ice cap throughout the climatic season. Only later, around Ötzi’s life, did large glaciers begin to form again at lower altitudes.

Meanwhile, according to the authors, the valuable climate archive of the Weissseespitze is in danger of being lost. Climate change could cause the ancient glacier to melt in the next two decades. (aeg / sda)