A lecturer from the University of the Free State (UFS) recently visited Gough Island in the South Atlantic Ocean as part of a study to better understand the landscape evolution of some subantarctic islands and their response to long-term climate change.
Dr. Liezel Rudolph, lecturer in the department of geography at the UFS, says a study of subantarctic islands shows that, in general, the Southern Hemisphere is experiencing a rise in temperature, with an increase in rainfall in some locations, and other areas becoming drier. The annual temperature and rainfall average remain the same in some places, but there is a change in seasonality and synoptic weather events.
The expedition was supported by the South African National Department of Forestry, Fisheries and the Environment, the National Research Foundation, and the Royal Society for the Protection of Birds.
This teacher of modules on process geomorphology and fieldwork techniques, says the objective of her work on the island was to do a geomorphological survey of the island and explore the suitability of geochronological dating techniques on the island’s substrate.
She explains that with geochronological methods one can determine the age of rock material as well as the rate of landscape change on the island. “In other words, dating when the volcano was formed and determining how long it takes for weathering to break down the rock material, and erosional processes to remove soil material.”
According to her, studying landscape change enables one to better understand climate change over a long period of time.
She says that the more regions are investigated, the clearer the picture of climate change will become. “The earth is a large, complex system. By studying climate change in one location, one cannot simply assume that the same type and rate of change is occurring everywhere else. It would be like imaging a 1 000-piece puzzle by building with 10 pieces. The Southern Hemisphere is predominantly ocean, which makes it difficult to pin down land-atmosphere interactions – but the subantarctic islands give us the opportunity to create data points for the Southern Hemisphere, which would otherwise be a very large missing piece of the puzzle,” explains Rudolph.
She says the interaction between ocean, atmosphere, and land remains complex and it is important to study the entire picture in order to fully understand how this is happening. Especially since the climate is changing at a drastic rate.
The research is taking place in collaboration with the British Antarctic Survey and is co-led by Prof Werner Nel from the University of Fort Hare, and Prof David Hedding from the University of South Africa.
