Properties and mechanisms of seawater exchange in Marian Cove, King George Island, West Antarctic Peninsula

Abstract

The Antarctic Peninsula is one region that has recently experienced warming substantially more rapidly than the global mean over the past 50 years. Marian Cove is located in the South Shetland Islands connected to the Bransfield Strait via Maxwell Bay between King George Island and Nelson Island. In this study, we identified properties and mechanisms of seawater exchange in Marian Cove from multiple hydrographic surveys and a single bottom-mounted mooring installed at the entrance to Marian Cove. Regardless of the season, the mean current velocity profiles at the entrance to Marian Cove were constant because of the influence of tidal forcing. Wind was the primary force that determined the variation in surface current; in response, a countercurrent occurred near the bottom area. We estimated salt transport to understand what effects Maxwell Bay′s saline water intrusion has on the Marian Cove environment. When the daily easterly wind was at its maximum of 18.5 m s-1, the salinity could increase to 7.20 × 10？4 g kg-1 in 1 day. In addition, the average freshwater residence time in Marian Cove for the quantitative evaluation of seawater exchange was approximately 9 days. However, the freshwater residence time was reduced to less than 2 days when there were extreme easterly winds.