The amount of sea ice around Antarctica has melted to a record low for January, scientists announced this week.

As of January 1, there was 2.11 million square miles of sea ice around the continent, the smallest January area since records began in 1978, according to the National Snow and Ice Data Center.

Sea ice is frozen ocean water that melts each summer, then refreezes each winter. Antarctic sea ice is typically at its smallest in late February or early March, toward the end of summer in the Southern Hemisphere.

“Antarctic sea ice extent is astonishingly low this year, not just…