The 8th National Antarctic Scientific Expedition, which was carried out under the auspices of the Presidency, under the responsibility of the Ministry of Industry and Technology and under the coordination of TÜBİTAK MAM Polar Research Institute, was successfully completed after 36 days.
During the expedition, scientists searched for clues about the planet's future by studying the continent's past in terrestrial areas on Horseshoe Island in Antarctica and in marine areas in Lystad Bay, part of Marguerite Bay.
Assoc. Prof. from Karadeniz Technical University, Department of Geophysics, who participated in the 8th National Antarctic Scientific Expedition. Dr. Murat Özkaptan completed his studies on the geological formation of the island, the tectonic movements of the Antarctic plate on which it lies, and the temporal variation of the Earth's magnetic field in the southern magnetic pole region with the project “Paleomagnetism of Horseshoe Island”: determination of tectonic and paleointensity Changes” in Marguerite Bay.
Assoc. DR. In his statement to the AA correspondent, Murat Özkaptan explained that he will study the paleomagnetic changes of Horseshoe Island as part of the project and said: “My project has two important motivations. The first is to reveal the temporal changes in the Earth's magnetic field, and the second is to reveal the tectonic rotation of the region using the rocks sampled from Horseshoe Island and its surroundings. said.
Emphasizing that humanity's conscious use of the magnetic field dates back about 2,000 years, Özkaptan explained that the magnetic field was first discovered by the Chinese and used as a guide for finding direction.
Özkaptan said: “It is a mysterious physical feature of the Earth that later paved the way for extremely important discoveries for the world of science. Although this feature is not perceived by our senses, it is extremely important for the self-preservation of living beings and nature. It acts as a kind of protective shield against harmful rays from the sun and space. gave his information.
Stating that this protective shield created by the magnetic field has weakened or strengthened from time to time over geological time, Özkaptan made the following assessment:
“Thanks to the samples of rocks of different ages that make up Horseshoe Island, information can be obtained about how the magnetic field behaved in past geological periods. By properly representing the behavior of the magnetic field in past periods, accurate prediction of changes in the future is provided. Only in this way will humanity be able, “We will try to produce extremely important data for projection studies on how the Earth's magnetic field, which is crucial to its continuity, might change.”
Özkaptan explained that the Earth's magnetic field penetrates the rocks during their formation and gives them orientation like a compass needle, saying that these magnetization directions obtained over geological time can change.
Emphasizing that the factor causing this change is tectonism, Özkaptan said: “Thanks to paleomagnetic samples taken from these rock groups in different geological ages and locations, information about the geological formation of the island as well as possible rotations is obtained – and positional differences between the rocks, and the tectonic deformation processes that caused them. In this way, “we will attempt to answer questions about the rotational change of Horseshoe Island and its surroundings at the local level and at the broader scale of how the Antarctic plate is moving on which the island is changing,” he said.
“We mapped the seafloor of Horseshoe Island in water depths ranging from 0 to 40 meters.”
Assoc. Prof. from Marine Sciences Management Institute of Istanbul University who participated in the 8th National Antarctic Science Expedition. Dr. Denizhan Vardar also conducted his project to “identify and map the glacier-derived structures of the shallow seafloor and nearshore areas using acoustic and high-resolution UAV photos and determine current glacier movements” in Lystad Bay west of Horseshoe Island.
Assoc. Dr. Vardar stated that his main task is to study the characteristics of the sea coast and seabed up to a water depth of about 40 meters and in this context he said that this also extends to the rock, sand and mud formations in the coastal and shallow marine areas are determined and the distribution and boundaries of benthic habitats are mapped.
Addressing the importance of understanding and researching the traces left underwater by glacial movements on the Antarctic continent, Vardar continued:
“We used our own institute’s side-scan sonar device to image the seabed. This device uses acoustic signals and shows a photorealistic image of the seabed. In this way, we mapped the seafloor of Horseshoe Island between 0 and 40 meters of water depth.
We then marked the mud and rock areas with some of the reflections we had seen and by identifying the areas of erosion and storage we now have ideas about the movements of the past ice age. Additionally, since the signal transmitted was an acoustic signal, ground verification was required in some areas. To do this, we drove to some points identified with the underwater drone system and took our pictures. By comparing the image with the reflection data we collected, we were able to confirm the seafloor. In this respect it was a successful study.”
“Traces of the past and present remain hidden under the sea”
Vardar stressed that the traces in the sea are very important, saying: “The traces of the past and the present remain hidden under the sea, they do not disappear like they do on land. Submarines are areas of continuous accumulation. Traces of accumulation and deformation.” The seabed here remains always hidden thanks to the protection of the water. That is the most important difference between land and sea.” “The sea constantly protects, the land constantly erodes and the eroded material enters the sea,” he said.
Assoc. Dr. Vardar explained that the difference of their work is to understand the characteristics of the seabed and in this context obtain information about the past.
Vardar said: “The entire history of Horseshoe Island, both its past and its present, is hidden beneath the sea. There are erosions on land and the time in between is sporadic, but if you look at the seabed and deeper than the sea.” On the seafloor you can see both the present and the past. All traces, all of the past are on the seabed and under the sea. “It's always obvious,” he said.
“If we understand what happened in the past and today, we can better understand our future.”
Assoc. Prof. from Gebze University of Technology who participated in the 8th National Antarctic Science Expedition. Dr. Mehmet Korhan Erturaç also completed the fieldwork of the project “Mapping and Dating the Graded Coastal Forms of Horseshoe Island”.
Erturaç, who researched the effects of melting Antarctic ice sheets on the increase in land area over the past 10,000 years to the present, explained that he studied landforms and deposits to understand the world's young history.
Erturaç stated that his goal, within the framework of TAE-8, was to describe the landforms that emerged on Horseshoe Island as a result of many different ground dynamics and continued as follows:
“The main reason or the basic approach and hypothesis of my project is actually glacial geomorphology, coastal geomorphology and riverine geomorphology. My focus is on the stepped landforms in Gaul Bay that are created by their interaction. By mapping and dating them. “I can analyze them in detail over time, from the past over the last 10,000 years to the present.” We are trying to understand how quickly the West Antarctic Peninsula is rising. If we understand the processes in the past and today we can better understand our future and what will happen to us and also try to understand the structures that have formed here over tens of thousands of years.
Today we live in the interglacial period. The formation of Gaul Bay, or more specifically, the formation of landforms throughout the Antarctic Peninsula, is a result of glacial erosion during these ice ages. It is created by the movement of glaciers. Gaul Bay is also a glacial valley. After the end of the Ice Age, the glaciers begin to retreat and melt, sea levels rise and the sea floods this glacial valley. Today we see the landform behind me and this retreating glacier directly in front of me. “It’s called the Shoesmith Glacier.”
Explaining that they are able to observe the sediments processed by the Shoesmith Glacier and the sea together, Erturaç said that they date these sediments step by step, one by one, using absolute methods, understanding when they were formed and they would map in detail with unmanned aerial vehicles and determine what the Antarctic continent, and particularly West Antarctica, looks like at that date and altitude. He said they were trying to understand how quickly it was rising.
Assoc. Dr. Mehmet Korhan Erturaç concluded his words by emphasizing that, according to a rough estimate, Horseshoe Island is rising between 1 and 2 centimeters per year:
“The reason for this increase is not tectonism, but the retreat of glaciers. In other words: we have a kilometer-thick glacier cover. As these glaciers melt and assume their current shape, land areas increase in response to this release of cargo. We're trying to measure this and the information we get from here applies to the whole of West Antarctica.” “It will give us very important data.”
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