In September of 1879, the Arctic-exploring USS Jeanette was sailing north of the Bering Strait when it was surrounded by ice floes and frozen in place. Imprisoned at sea, the 33-person crew struggled to survive for nearly two years before their ship sank, forcing them to embark on a perilous journey back to civilization. While they were stranded, the crew took down regular observations of the weather—winds, clouds, air pressure, temperature—creating a detailed meteorological record where no others existed.

One hundred and forty years later, that record is now helping scientists reconstruct Earth’s weather and climate history in unprecedented detail.

The USS Jeanette’s logs, which eventually made their way back to the United States along with 13 haggard crewmen