The coldest location on the planet has experienced an episode of warm weather this week unlike any ever observed, with temperatures over the eastern Antarctic ice sheet soaring 50 to 90 degrees above normal. The warmth has smashed records and shocked scientists.

“This event is completely unprecedented and upended our expectations about the Antarctic climate system,” said Jonathan Wille, a researcher studying polar meteorology at Université Grenoble Alpes in France, in an email.

“Antarctic climatology has been rewritten,” tweeted Stefano Di Battista, a researcher who has published studies on Antarctic temperatures. He added that such temperature anomalies would have been considered “impossible” and “unthinkable” before they actually occurred.

Parts of eastern Antarctica have seen temperatures hover 70 degrees (40 Celsius) above normal for three days and counting, Wille said. He likened the event to the June heat wave in the Pacific Northwest, which scientists concluded would have been “virtually impossible” without human-caused climate change.