Last updated: January 20, 2018 at 4:49 am
Seawater with an average salinity of 35 ppt (parts per thousand) freezes at -1.94°C (28.5°F). The coldest seawater ever recorded at −2.6 °C (27.3 °F) was found in a stream under an Antarctic glacier.
“Sea ice covers about 7% of the Earth’s surface and about 12% of the world’s oceans. Much of the world’s sea ice is enclosed within the polar ice packs in the Earth’s polar regions: the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean.”¹