Study reveals late Pleistocene island weathering, precipitation in the Western Pacific Warm Pool
In a study published in npj Climate and Atmospheric Science on April 18, researchers from China, South Korea, France, the United Kingdom, and the United States have reconstructed the weathering history of the Western Pacific ...
The tropical western Pacific island arc is dominated by basalt-ultrabasic basalts. Under the combined influence of the suitable climate (high temperature and heavy precipitation) in the tropical warm pool area and the steep elevation drop of the island (few lowland plains, weathered sediments can't be retained in the basin), the weathering and denudation rate is fast and the impact on the marine environment may be greater than traditionally expected. What are the main mechanisms controlling the weathering of tropical island arcs? How does such a large amount of basalt weathering respond to climate change?
With these questions in mind, the researchers selected core MD01-2385, located in the core area of the WPWP, and extracted three mineralogical and elemental geochemical weathering records from northwest of New Guinea Island, to reconstruct the island's weathering history over 140,000 years.
They found that the weathering records of the western Pacific islands show the characteristics of precession cycle control, which is obviously different from the changes of sea surface temperature controlled by eccentricity.
"This phenomenon implies that the weathering record is mainly controlled by the deep convection-precipitation evolution in the warm pool, and therefore can be used to indicate the history of the deep convection-precipitation evolution in the warm pool," said Dr. Yu Zhaojie from the Institute of Oceanology of the Chinese Academy of Sciences, first author of the study.
Schematic diagram of research station location and regional environment. Credit: Yu Zhaojie