Richard StoneOn a spring day in 2019, Alexander Kizyakov rappelled down the 60-meter headwall of the Batagay megaslump in eastern Siberia, pausing to chisel out chunks of ice-rich soil that had been frozen for eons. “One of my hobbies is rock climbing,” says Kizyakov, a permafrost scientist at Lomonosov Moscow State University.
Colleagues below sampled the most ancient soil along the base of the cliff. Such work is too dangerous in summertime, when the constant crackling of melting ice is punctuated by groans as slabs of permafrost, some as big as cars, shear off the headwall.Known to locals as the “gateway to the underworld,” Batagay is the largest thaw slump on the planet.