Glaciologists Andrea Fischer and Martin Stocker-Waldhuber, from the Austrian Academy of Sciences, inspect the entrance of a natural glacier cavity of the Jamtalferner glacier near Galtuer, Austria, October 15, 2021. Giant ice caves have appeared in glaciers accelerating the melting process faster than expected as warmer air rushes through the ice mass until it collapses. Picture taken October 15, 2021. REUTERS/Lisi Niesner