据研究人员介绍，气候变化使极地地区越来越容易发生大型滑坡。最近在格陵兰岛发生了引发海啸的山体滑坡，但没有东部峡湾发生的报道。
2023年9月，研究人员探测到一个为期9天的全球10.88毫赫(92秒)，单色超长周期(VLP)地震信号的开始，该信号来自东格陵兰岛。在这项研究中，研究人员展示了这一事件是如何开始的，由冰川变薄引起的25×106立方米的岩冰雪崩开始，该雪崩落入迪克森峡湾，引发了200米高的海啸。
模拟显示，海啸稳定成一个7米高的长时间假潮，其频率(11.45毫赫)和缓慢的振幅衰减与地震信号几乎相同。最大振幅为5×1011牛顿的峡湾横向单力，再现了地震振幅及其相对于峡湾的辐射模式，证明了假潮是如何直接引导长达9天的地震信号的。该研究结果强调了气候变化是如何，在冰冻圈、水圈和岩石圈之间形成层叠的、有害的反馈。
附：英文原文
Title: A rockslide-generated tsunami in a Greenland fjord rang Earth for 9 days
Author: Kristian Svennevig, Stephen P. Hicks, Thomas Forbriger, Thomas Lecocq, Rudolf Widmer-Schnidrig, Anne Mangeney, Clément Hibert, Niels J. Korsgaard, Antoine Lucas, Claudio Satriano, Robert E. Anthony, Aurélien Mordret, Sven Schippkus, Sren Rysgaard, Wieter Boone, Steven J. Gibbons, Kristen L. Cook, Sylfest Glimsdal, Finn Lvholt, Koen Van Noten, Jelle D. Assink, Alexis Marboeuf, Anthony Lomax, Kris Vanneste, Taka’aki Taira, Matteo Spagnolo, Raphael De Plaen, Paula Koelemeijer, Carl Ebeling, Andrea Cannata, William D. Harcourt, David G. Cornwell, Corentin Caudron, Piero Poli, Pascal Bernard, Eric Larose, Eleonore Stutzmann, Peter H. Voss, Bjorn Lund, Flavio Cannavo, Manuel J. Castro-Díaz, Esteban Chaves, Trine Dahl-Jensen, Nicolas De Pinho Dias, Aline Déprez, Roeland Develter, Douglas Dreger, Lslo G. Evers, Enrique D. Fernández-Nieto, Ana M. G. Ferreira, Gareth Funning, Alice-Agnes Gabriel, Marc Hendrickx, Alan L. Kafka, Marie Keiding, Jeffrey Kerby, Shfaqat A. Khan, Andreas Kjr Dideriksen, Oliver D. Lamb, Tine B. Larsen, Bradley Lipovsky, Ikha Magdalena, Jean-Philippe Malet, Mikkel Myrup, Luis Rivera, Eugenio Ruiz-Castillo, Selina Wetter, Bastien Wirtz
Issue&Volume: 2024-09-13
Abstract: Climate change is increasingly predisposing polar regions to large landslides. Tsunamigenic landslides have occurred recently in Greenland (Kalaallit Nunaat), but none have been reported from the eastern fjords. In September 2023, we detected the start of a 9-day-long, global 10.88-millihertz (92-second) monochromatic very-long-period (VLP) seismic signal, originating from East Greenland. In this study, we demonstrate how this event started with a glacial thinning–induced rock-ice avalanche of 25 × 106 cubic meters plunging into Dickson Fjord, triggering a 200-meter-high tsunami. Simulations show that the tsunami stabilized into a 7-meter-high long-duration seiche with a frequency (11.45 millihertz) and slow amplitude decay that were nearly identical to the seismic signal. An oscillating, fjord-transverse single force with a maximum amplitude of 5 × 1011 newtons reproduced the seismic amplitudes and their radiation pattern relative to the fjord, demonstrating how a seiche directly caused the 9-day-long seismic signal. Our findings highlight how climate change is causing cascading, hazardous feedbacks between the cryosphere, hydrosphere, and lithosphere.
DOI: adm9247
Source: https://www.science.org/doi/10.1126/science.adm9247