Seal‐mounted sensors measure seasonal flows under Antarctic ice

Abstract

Researchers have questioned whether flows of warm deep water into Antarctica's Weddell Sea from farther north might vary seasonally, but hostile Antarctic conditions have made observations difficult. Årthun et al. turned to an unusual approach to measure water temperatures: They attached sensors to the heads of seals. The scientists glued conductivity‐temperature‐depth sensors to the heads of 19 Weddell seals and then loosed them in the region. Over an 8‐month period starting in February 2011, the seals' sensors captured 9000 temperature‐salinity profiles of the conditions under the ice. One region, the Filchner Ice Shelf Front, was particularly well sampled, as a single seal swam up and down 451 times throughout the study period. The authors' seal‐enabled observations were supported by an existing 3‐year‐long profile provided by a fixed sensor.