Hydrography of Marian Cove, King George Island, West Antarctica: implications for ice-proximal sedimentation during summer

Abstract

During the summer, from 1996–2000, vertical profiles of conductivity, temperature and transmissivity were obtained near the tidewater glacier of Marian Cove, King George Island, Antarctic Peninsula. The aims for the study were to determine the short-term variations of water structure due to hydrographic forcings and to understand sedimentation of suspended particulate matter in Antarctic fjord environments. Four distinct water layers were identified in the ice-proximal zone of the cove: i) a surface layer composed of cold and turbid meltwater, ii) a relatively warm Maxwell Bay inflow layer with characteristics of outer fjord water, iii) a turbid/cold mid-depth layer (40–70 m) originating from subglacial discharge, and iv) a deep layer comprised of the remnant winter water. The main factor influencing the characteristics of glacial meltwater layers and driving deposition of suspended particles in the cove is tidal forcing coupled with wind stress. The relatively small amount of meltwater discharge in Marian Cove yields low accumulation rates of non-biogenic sedimentary particles in the cove. The response to north-western and western winds, coupled with flood tide, may promote settling and sedimentation of suspended particles from turbid layers in the ice-proximal zone of the cove.

Glacier sediment plumes in small bays on the Danco Coast, Antarctic Peninsula

“…All of the data from the other bays corroborate that measurements taken during a flood tide were less intense, even with similar hydrographic characteristics. The same behaviour was noticed by Yoo et al (2015) in Marian Cove, who argued that flood tide with a wind toward the head of the cove may result in settling of the particles in the ice-proximal zone.…”

“…8). Further from the source, larger particles cannot be transported (McClimans 1978, Trusel et al 2010), and mixture processes and forces associated with the current dynamics weaken or alter the plumes (Yoo et al 2015), thus the plume extension is limited. Similar values for plume extension were reported by Zajączkowski (2008) for fjords in Svalbard in the Arctic.…”

First record of massive blooming of benthic diatoms and their association with megabenthic filter feeders on the shallow seafloor of an Antarctic Fjord: Does glacier melting fuel the bloom?

“…Marked summer time bloom in water columns dominated by benthic diatom has been reported (Ahn et al 1997;Kang et al 2002). Further information on the environmental features of this area has been described by Moon et al (2015) and Yoo et al (2015).…”

“…Tidewater glaciers are well-developed at the end of the cove, and these glaciers have retreated approximately 1.7 km from 1956 to 2012 Moon et al 2015;Park et al 1998). Glacial carving and snow melting begin in early summer and persist throughout the austral summer, introducing considerable amounts of floating ice and turbid meltwater that develop a very distinct environmental gradient in the seawater (Ahn et al 2004;Moon et al 2015;Yoo et al 1999Yoo et al , 2002Yoo et al , 2015Yoon et al 1998). Even after the summer season, haphazard break-up of the glacier occurs continuously until June when the winter season begins (personal observation while wintering in 2015).…”

“…Even after the summer season, haphazard break-up of the glacier occurs continuously until June when the winter season begins (personal observation while wintering in 2015). Details of the hydrographic features in the cove have been described by Yoo et al (2015).…”