Commentary on JGR-Sold Earth Paper 'Deep Seismic Structure Across the Southernmost Mariana Trench: Implications for Arc Rifting and Plate Hydration' by Wan et al.

摘要

Among Earth's physical features, the Challenger Deep is especially aptly named. As the deepest place on Earth's solid surface, it continues to challenge our understanding as it challenges us to descend and touch the bottom. The latter was the challenge that the U.S. Navy team of Auguste Picard and Don Walsh responded to on 23 January 1960 when they descended in the bathyscaphe TRIESTE to the bottom of the Challenger Deep 10,916 m below sea level, the one that Canadian film director James Cameron responded to in March 2012, and the one that Dallas businessman Victor Vescovo responded to in April 2019 when they also went down to the bottom of this trench. Their efforts are testaments to human determination, ingenuity, will, and resources. But "touching bottom" is not the only challenge that the Challenger Deep presents us: It also challenges us to understand it-what caused it, what the rocks on either flank are made of, what, if anything, is different about the seawater that fills it, what kinds of sediments rest on the seafloor, and what kind of life is found there. Solving the "Challenger Deep Puzzle" requires exploring not only the deepest points but also the hyper-deep-sea environment for hundreds of kilometers around it.