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Landscape change studies bring better understanding of climate change

03 November 2022 | Story Leonie Bolleurs | Photo Supplied

A study of subantarctic islands tells us 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.

This is according to Dr Liezel Rudolph, a lecturer in the Department of Geography at the University of the Free State (UFS). She recently returned from an expedition to Gough Island in the South Atlantic Ocean, 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 at the UFS, 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.”

The research she is involved in, forms part of a SANAP-NRF-funded project, Sub-Antarctic Landscape Climate Interactions, which aims to better understand the landscape evolution of some subantarctic Islands and their response to long-term climate change.

Studying the past to understand the present

According to her, studying landscape change enables one to better understand climate change over a long period of time.

She states 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 Dr 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.

Dr Rudolph, whose research at the UFS is focused on constraining the last glaciation of subantarctic Marion Island though various proxies and dating techniques, says the subantarctic islands are very sensitive to changes in climate.

A clearer picture of climate change

She was part of previous expeditions to the island. Although all these expeditions had different goals, according to her, they all aimed to answer the same questions, which are how the island’s landscape has developed throughout history and what the climatic drivers were during its evolution.

“The landscape responds to changes in temperature and precipitation. Under colder, wetter conditions – when the island’s surface is subject to a freeze-thaw process – a range of peri-glacial landforms will develop. These landforms will still be evident in the landscape years later under a different climate, for example, warmer or drier conditions. We can study these landforms in real-time and establish whether they are actively forming or are relict features that formed under different climatic environments,” remarks Dr Rudolph.

The research, which is taking place in collaboration with the British Antarctic Survey, is co-led by Prof Werner Nel from the University of Fort Hare, and Prof David Hedding from the University of South Africa.

• Dr Rudolph is grateful to the Government of Tristan da Cunha, which is responsible for managing the conservation of Gough Island, for permitting them to do scientific work on the island.

News Archive

UFS involved in project to light up the townships

2006-06-06

The parties involved with the project are from the left: Prof Hendrik Swart (Departmental Chairperson of the UFS Department of Physics), Dr Thembela Hillie (CSIR), Prof Neerich Revaprasadu (Department of Chemistry at the University of Zululand) and Dr Wynand Steyn (CSIR).

UFS involved in project that could light up the townships

The University of the Free State’s (UFS) Department of Physics is involved with a project that could make life easier in the townships through the use of artificial light.

“The project is based on the use of sunlight to activate nano material in for example cement and paint during the day. At night the cement or paint can then radiate light,” said Prof Hendrik Swart, Departmental Chairperson of the UFS Department of Physics.

According to Prof Swart an amount of R3,9 million has been made available by the Council for Scientific and Industrial Research (CSIR) for the further development of the project.

Prof Swart visited the University of Florida in America in 1995 for a year where he researched luminescent phosphor material that is suitable for flat panel television screens. The red, green and blue spots on the television screens originate from these kinds of phosphor materials. “At that stage plasma television screens were only a dream. Today it is sold everywhere,” said Prof Swart.

“Upon my return I started a research group at the UFS which investigated the degrading of phosphor material. We also started to concentrate on the effectiveness of nano phosphors. In the mean time our cooperation with the Americans was strengthened with follow-up visits to America of my colleagues, Prof Koos Terblans and Mr Martin Ntwaeaborwa,” said Prof Swart.

“Nano phosphors are basically luminescent powders that consist of particles that are 1 millionth of a millimetre. These particles can provide light as soon as they are illuminated with, for instance, sunlight. The amount of time these particles can provide light, is determined by the impurities in the material,” said Prof Swart.

According to Prof Swart nano particles are developed and linked to infrastructure materials in order for these materials to be excited during the day by sunlight and then it emits light during night time.

“The nano material is of such a nature that it can be mixed with materials, such as paint or cement. The yellow lines of roads can for example emit light in a natural way during night time,” said Prof Swart.

About a year ago Prof Swart and Dr Thembela Hillie, a former Ph D-student of the UFS Department of Physics, had discussions with Prof Neerich Revaprasadu from the University of Zululand and the CSIR about the possibility of mixing these nano phosphor particles with other materials that can be used as light sources in the building of roads and houses.

“Prof Revaprasadu is also actively involved in the research of nano materials. Our efforts resulted in the CSIR approving the further extension of the project,” said Prof Swart.

“The UFS and the University of Zululand are currently busy investigating ways to extend the light emitting time,” said Prof Swart.

“There are eight M Sc and Ph D-students from the UFS and about five students from the University of Zululand working on this research project. The Department of Physics at the Qwaqwa Campus of the UFS, with Francis Dejene as subject head, is also involved with the project,” said Prof Swart.

According to Prof Swart the further applications of nano materials are unlimited. “Children whose parents cannot afford electricity can for instance leave any object such as a lamp, that is covered with these phosphor particles, in the sun during the day and use it at night as a light for study purposes,” said Prof Swart.

According to Prof Swart the further extension of the project will take about two years. “During this time we want to determine how the effectiveness of the phosphors can be increased. Discussions with the government and other role players for the possible implementation of the project are also part of our planning,” said Prof Swart.

Media release
Issued by: Lacea Loader
Media Representative
Tel: (051) 401-2584
Cell: 083 645 2454
E-mail: loaderl.stg@mail.uovs.ac.za
6 June 2006

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