Experts Examine Stalagmites in a Serbian Cave, Stunned to Learn About the Climate Conditions 2,500 Years Ago
Climate records are not the easiest in the world to analyze. Experts typically depend on satellite records, and for times when space technology was not present, they turn to nature for answers. One of the places experts have turned to for clues is Serbian caves, stated The Economist. Details on how experts analyze the caves to understand past climate have been published in Geology.
The cave elements that give the past climate insights are stalagmites, as per the study. Researchers claim that the chemical makeup of these rock formations reflects past climate conditions. The study explains that these formations are created very slowly over time, with water dripping from rocks. The stalagmite is formed due to the accumulation of minerals in the droplets. Analysis of the chemical makeup will showcase the features of water that make it. The mineral content of water would possibly fluctuate depending on the time it was collected on the cave surface. The fluctuation would allow researchers to understand the climate of that particular period.
Researchers were focused on the northern polar jet stream. This phenomenon impacts the climatic conditions of northern Europe. These winds have the power to transport cold air from the Arctic over the American Midwest, as well as to bring storms to Ireland. Before the study, there was a speculation that this jet stream had become powerful over time because of climate change. Experts associated with the study analyzed stalagmites from Serbian caves to verify this claim.
Serbia's rain depends heavily on the northern polar jet streams. If it is strong, then rain clouds arrive in the region from the Atlantic Ocean; on the other hand, if it is weak, then rain clouds come from the Mediterranean. Water from both clouds has a different chemical composition. The Mediterranean rain has more of oxygen-18, while Atlantic water has less of this isotope. Researchers analyzed the stalagmites and tried to identify which layers had more of this isotope and which had less. This identification showcased what kind of clouds the region was more exposed to in the past. The pattern further sheds light on the jet stream's strength.
Two stalagmites were examined in the study, one 380mm specimen from Cerjanska cave and one 238mm specimen from Prekonoska cave. Analysis indicated that the Cerjanska specimen grew between 434 B.C. and 1913, while the Perkonoska specimen formed between 798 B.C. and 404 C.E. The layers indicated that the North Atlantic jet streams are the strongest in the modern period. Past findings have showcased that the warm period of this region lasted from 300 B.C. to 200 B.C., while the colder phase continued from 300 to 700 C.E. Researchers were surprised to uncover that jet streams were stronger during the cooler period than the warmer, completely opposite to what is observed now in the environment.
Researchers are yet to figure out why jet streams changed their pattern. Experts speculate this is because of the North Atlantic Warming Hole, a blob of cold water that has possibly formed because of the melting of Greenland’s ice sheets. This implies that jet streams have been impacted by climate change. For a clearer picture, experts want to analyze more stalagmites.