A team of researchers reports Antarctica’s enormous Thwaites Glacier is on the verge of collapse, with warm water seeping under the weakest parts of the glacier and melting it from below. Researchers deployed a robotic submarine to penetrate the vast ice sheet, which is roughly the size of Florida. They found the glacier is susceptible to rapid and irreversible ice loss that could raise global sea levels by more than half a meter. Its collapse could destabilize surrounding glaciers that could raise the Earth’s oceans by a further three meters — or nearly 10 feet.