Erebus Glacier Tongue

Erebus Glacier Tongue. It is a prominent floating glacier tongue extending from the Mount Erebus stratovolcano on Ross Island into the southwestern Ross Sea. This dynamic ice formation is a significant feature of the McMurdo Sound region, serving as a critical site for studying glaciology, oceanography, and polar ecology. Its stability and interactions with sea ice are influenced by the unique conditions of the Ross Ice Shelf and the Southern Ocean.

Geography and location

The glacier tongue projects northwest from the coast of Ross Island into McMurdo Sound. It is situated near major scientific stations, including McMurdo Station operated by the United States Antarctic Program and Scott Base managed by Antarctica New Zealand. The feature lies to the south of Hut Point Peninsula and is flanked by the Erebus Ice Tongue to its east. Its position makes it a conspicuous landmark for vessels traversing the Ross Sea, including those supporting the Italian National Antarctic Research Programme and other international expeditions. The surrounding area includes notable features like Cape Evans, associated with the British Antarctic Expedition led by Robert Falcon Scott.

Physical characteristics

The tongue is a tabular body of ice approximately 12 kilometers long and 70 square kilometers in area, with a thickness ranging from 50 to 100 meters. Its surface is characterized by extensive crevasse fields and serac formations, resulting from intense strain as the ice flows from Mount Erebus. The structure exhibits classic features of a floating glacier, including a distinct grounding line where it detaches from the bedrock. Studies by organizations like the British Antarctic Survey and the Alfred Wegener Institute have documented its thermal regime and internal structure. The ice composition includes clear blue ice areas, indicative of old, compressed firn, and is subject to ablation from solar radiation and katabatic winds from the Transantarctic Mountains.

Formation and dynamics

The tongue originates from the convergence of several ice streams flowing from the slopes of Mount Erebus, an active volcano within the West Antarctic Rift System. Its formation is driven by the continuous accumulation and compaction of snow within the Erebus Glacier catchment area. Once the ice flow reaches the coast at a high velocity, it becomes buoyant and extends seaward, forming the floating tongue. Its dynamics are governed by complex interactions between glacial flow, tidal flexing from the Ross Sea, and basal melting from relatively warm Circumpolar Deep Water. Calving events, influenced by storms and ocean currents, periodically truncate its length, as documented during the International Geophysical Year. The long-term stability of the feature is a key indicator for changes in the wider Ross Ice Shelf system.

Research and exploration

The site has been a focus of scientific investigation since the heroic age of Antarctic exploration, with early observations made by expeditions like the Discovery Expedition and the Terra Nova Expedition. Modern research programs, including those by the National Science Foundation and the Australian Antarctic Division, utilize it for deploying oceanographic sensors and studying ice-ocean interactions. It serves as a natural laboratory for investigating topics such as sea ice formation, plate tectonics due to its volcanic origin, and extremophile microbial communities. Remote sensing data from satellites like Landsat and ICESat, combined with field campaigns such as those of the German Antarctic Receiving Station, have greatly advanced understanding of its mass balance and response to climate forcing.

Interaction with the Ross Sea

The glacier tongue plays a significant role in the local marine environment of the Ross Sea. It acts as a physical barrier, influencing the formation and movement of pack ice within McMurdo Sound and affecting polynya dynamics. Its submerged base provides a unique habitat for phytoplankton blooms and krill populations, which support higher trophic levels like Weddell seal and Emperor penguin colonies. The calving of icebergs from its terminus contributes freshwater and sediment to the Southern Ocean, impacting nutrient cycles. Oceanographic studies, including those from the RV Nathaniel B. Palmer, show that meltwater from its base can alter water column stratification. Its presence also affects coastal currents documented by the Japanese Antarctic Research Expedition, making it integral to regional oceanographic models.

Category:Glaciers of Ross Island Category:McMurdo Sound