40-million-year-old enormous river system found deep beneath West Antarctica
Deep beneath the thick ice sheet of West Antarctica, geologists have made a remarkable discovery - the remnants of an ancient river system that once spanned nearly a thousand miles. Published in the journal Science Advances, this finding not only provides valuable insight into Earth's history but also offers a glimpse into the potential ramifications of extreme climate change. This is prepared by SSP.
Johann Klages, a sedimentologist at the Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, emphasized the importance of studying Earth's past to better understand and prepare for future climate scenarios. He stated, "If we think about a potentially severe climate change in the future, we need to learn from periods in Earth's history where this already happened."
The discovered river system dates back approximately 34 to 44 million years ago, during the middle-to-late Eocene epoch, characterized by dramatic transformations in the Earth's atmosphere. As carbon dioxide levels decreased, a global cooling phenomenon ensued, leading to the formation of glaciers on an otherwise ice-free planet.
The fascination lies in understanding how this significant climate event ensued in Antarctica, particularly because modern greenhouse gas emissions continue to drive up carbon dioxide levels. During the late Eocene period, carbon dioxide levels were nearly double what they are today. Nonetheless, if current greenhouse gas trends persist, experts predict that CO2 levels could reach similar levels in approximately 150 to 200 years.
Revealing the secrets of the past has presented challenges due to the extensive ice coverage in West Antarctica. Accessing sedimentary rocks, crucial in studying past environments, proves to be difficult beneath the ice. These rocks hold valuable clues in the form of grains, minerals, and fossils, offering insights into the conditions that prevailed in a particular area.
In 2017, Johann Klages and a team of scientists embarked on the Polarstern expedition, a voyage spanning the expanse from the southernmost part of Chile, crossing the treacherous Drake Passage, and venturing into the icy western region of the continent. Equipped with cutting-edge seafloor drilling technology, they aimed to extract core samples from both soft sediments and robust rocks concealed within the frozen seabed.