Long-term monitoring of Arctic shorefast sea ice along whale hunting trails at Utqiaġvik, Alaska

Abstract:

Shorefast sea ice along Alaska’s northern coasts forms and evolves throughout fall, winter, and spring in response to air and near-surface sea temperatures, ocean dynamics, and interaction with the mobile pack ice. It provides a habitat for marine mammals, a buffer between land and ocean, and an ephemerally stable corridor and platform for travel and hunting by Alaska’s Iñupiat, Central Yup’ik, Cup’ik, and St. Lawrence Island Yupik peoples. At Utqiaġvik, Alaska, hunters build an extensive network of trails across the shorefast sea ice each spring to access bowhead whale hunting sites. Since 2007, the whaling community, North Slope Borough personnel, and scientists have mapped and surveyed ice thickness along these trails using a sled-based electromagnetic induction instrument to assess their stability, provide maps and ice-type information to hunters, and build a long-term dataset for how the ice is responding to a warming climate. These annual surveys track key ice characteristics, such as the modal thicknesses of level first-year ice, while also revealing hunter decisions for how to safely utilize and navigate the ice conditions they encounter each spring. This ice-trail dataset exists alongside an extensive collection of over 7,500 local observations made by hunters since 2006 regarding how the Iñupiat observe, understand, and respond to ice, weather, and other environmental variables throughout the year. These coordinated community-based observing initiatives, led as the Alaska Arctic Observatory & Knowledge Hub (AAOKH), provide sustained long-term observations of shifting environmental conditions in the Arctic, thus providing useful remote sensing data and forecasting products to coastal Arctic Indigenous Peoples, such as local maps showing areas of heavily ridged vs thin shorefast ice, breakup forecasts, locations of trails as a navigation aide, etc.