University lecturer reflects on Antarctica adventures
Dr Jeff Evans was part of special research expedition
AN ACADEMIC from Loughborough University has shared his experiences of life in Antarctica aboard a research vessel.
At the start of January, Dr Jeff Evans, a senior lecturer in physical geography in the School of Social Sciences, boarded the 134m-long S. A. Agulhas II – one of the largest and most modern research ships anywhere in the world.
He joined more than 30 international scientists from different scientific fields and renowned organisations on the Weddell Sea Expedition, which is to attempt to locate and survey Sir Ernest Shackleton’s lost ship Endurance, and increase understanding of Larsen-C, one of the largest ice shelves in Antarctica.
The expedition’s science programme has been completed and many of the scientists – including Dr Evans – have now bid a fond farewell to the S.A. Agul has II as it heads to the Endurance wreck site.
Dr Evans carried out extensive research into ice-mass and environmental change in the Arctic and Antarctic and participated and co-led the coring work on Larsen-C.
He said: “Much of our time has been spent along the edge of the Larsen-C Ice Shelf where science operations involved repeated oceanographic measurements of the water column adjacent to the ice shelf to determine the volume and rate of fresh, cold ice-shelf water formation due to the melting of the ice shelf base and the intrusion of relatively warmer water masses from the Weddell Sea under the ice shelf.
“We also continued to core sea-floor sediments along the front of the Larsen-C Ice Shelf.
“Coring of sediments in the region has proved a challenge with many coring attempts failing.”
During his trip they used two autonomous underwater vehicles (AUV) and their downward and upward looking swath systems to image the underside of sea-ice floes and sea-floor areas inaccessible to the ship.
AUV surveys of the underside of a range of ice-floes were undertaken in order to measure the roughness or irregularity and depth of the sea ice base.
AUV surveys of the underside of seaice floes are not without their challenges.
He said: “It was during the survey of a multi-year sea-ice floe (ice thickness of 20–30m) that the AUV terminated its mission due to an error and it surfaced under the ice floe and became trapped in an ice cavity rather than surfacing in open water.
“This meant that the ship had to carefully and incrementally break the ice floe in order to get closer to the trapped AUV.”
Dr Evans said the favourable sea-ice conditions next to the Larsen-C Ice Shelf changed towards the end of the planned science time.
He said: “Prolonged easterly to southeasterly winds caused the dense pack ice to spill around the northern end of A68 and to start filling the open water between the iceberg and the ice shelf edge.
“Therefore, the science programme at the Larsen-C Ice Shelf was curtailed a day earlier than originally planned, and instead, our science efforts were switched to the more partially sea-ice covered waters of the Larsen-B and Larsen-A areas to the north.”
The ship is currently headed to the Endurance wreck site where technicians from Ocean Infinity, Deep Ocean Search and Eclipse will undertake the search.
The search for the wreck is expected to be extremely challenging in terms of negotiating the ice and deploying and recovering the AUV.
The sea-floor in the Endurance wreck search area is mainly flat, so any ship wreck or associated debris should stand out, and the cold oxygen-poor waters will prevent decay or rotting of the ship’s wooden hull.