evidence: Usually, glaciers move at a glacial pace. The speedy collapse of the Conger's ice shelf came after some of the most dramatically warm weather ever observed in Antarctica. For the first time since satellite monitoring began in 1979, the sea ice extent around Antarctica dropped below 2 million sq km (770,000 sq miles). Less sea ice means more waves battering the ice shelves in front of the glaciers. Massive fields of sea ice off of Adelie Land, Wilkes Land and Princess Elizabeth Land in East Antarctica completely disappeared. The lack of ice startled scientists. Unlike in the Arctic, Antarctic sea ice had been slightly increasing over the period that satellites had been able to monitor it, and some suggested that circumpolar winds and ocean currents were isolating it from global warming. A study later blamed the 2022 sea ice low on ocean heating, as well as intense winds driven by La Niña and other weather patterns. [...] "If you're going to apply a really sophisticated model over a topography that's just flat because you've got no data, it's pointless," Siegert says. Antarctica's ice is melting not from above but from below. As relatively warm ocean water eats away at the sloping underside of an ice shelf, the grounding line where it meets the seafloor recedes. That process should stop at the coast – unless the bottom of the glacier there is below sea level. The Icecap planes' ice-penetrating radars helped discover a "weak underbelly" below East Antarctica's largest glacier Totten, which holds about as much potential sea level rise as all of West Antarctica.