Hydrothermal discharge to coastal ocean waters at Deception Island, Antarctica

We investigate the chemical composition of water associated with the active volcano at Deception Island, Antarctica. Temperature and salinity profiles observed at the middle of the bay are typical for normal seawater in a polar region and are influenced by wind-driven mixing. Interstitial water samples collected from beach sand ranged in temperature from ambient (-1.5 to +0.5 degreesC) to 90 degreesC. A thermal anomaly of 7-15 degreesC was observed in the waters along the shore during November, but not May. Hydrothermal components, such as dissolved iron and silica, are higher in and around Deception Island than in the Drake Passage. Dissolved iron was 10 to 100 times higher and dissolved silica was 4 to 6 times higher in some peripheral coves than in the middle of the bay. We suggest that tidal flushing carries dissolved components acquired by geochemical reactions within the bay out into the Bransfield Strait.