Arctic
Sea Ice, 36"
H x 32" W
Sea ice is a thin layer typically 1-5 meters thick that freezes in winter and partially melts in the summer. It is covered by a bright layer of snow which reflects around 85% of incoming solar radiation back out to space, acting like a large reflective blanket. As the sea ice melts, absorption rates increase, resulting in a positive feedback loop where the rapid pace of ocean warming further amplifies sea ice melt, contributing to even faster ocean warming. Sea ice volume in April 2021 was the lowest observed since records began in 2010. The Arctic continues to warm more than twice as fast as the rest of the globe.
Contemporary satellite imagery and sensor technology capture the Arctic sea ice's thickness and age, providing a fascinating look at recent melting data. Text describes the environmental significance of Arctic sea ice. The trend toward younger, thinner ice over time reflects warming temperatures in the Arctic. As older ice is thicker than younger ice, the reduced area of old ice also indicates a reduction in the total volume of ice. For more info, consult the NOAA Arctic Report Card and an update on Sea Ice.
Text from a Roald Admunsen journal describes his 1904 navigation of the Northwest Passage. (Roald Amundsen's "The North West Passage": Being the Record of a voyage of exploration of the ship "Gjoa" 1903-1907, Volume 1 is on Google Books). Other text describes the geographic parameters of the Northwest Passage.