Dura Tina, Garner Andra J, Weiss Robert, Kopp Robert E, Engelhart Simon E, Witter Robert C, Briggs Richard W, Mueller Charles S, Nelson Alan R, Horton Benjamin P
Department of Geosciences, Virginia Tech, Blacksburg, VA, 24061, USA.
Center for Coastal Studies, Virginia Tech, Blacksburg, VA, 24061, USA.
Nat Commun. 2021 Dec 8;12(1):7119. doi: 10.1038/s41467-021-27445-8.
The amplification of coastal hazards such as distant-source tsunamis under future relative sea-level rise (RSLR) is poorly constrained. In southern California, the Alaska-Aleutian subduction zone has been identified as an earthquake source region of particular concern for a worst-case scenario distant-source tsunami. Here, we explore how RSLR over the next century will influence future maximum nearshore tsunami heights (MNTH) at the Ports of Los Angeles and Long Beach. Earthquake and tsunami modeling combined with local probabilistic RSLR projections show the increased potential for more frequent, relatively low magnitude earthquakes to produce distant-source tsunamis that exceed historically observed MNTH. By 2100, under RSLR projections for a high-emissions representative concentration pathway (RCP8.5), the earthquake magnitude required to produce >1 m MNTH falls from ~M9.1 (required today) to M8.0, a magnitude that is ~6.7 times more frequent along the Alaska-Aleutian subduction zone.
未来相对海平面上升（RSLR）情况下，诸如远源海啸等沿海灾害的放大效应目前还缺乏充分的约束。在南加州，阿拉斯加 - 阿留申俯冲带已被确定为在最坏情况下远源海啸特别值得关注的地震源区。在此，我们探讨下个世纪的相对海平面上升将如何影响洛杉矶港和长滩港未来的最大近岸海啸高度（MNTH）。地震和海啸建模与当地概率性相对海平面上升预测相结合表明，更频繁、震级相对较低的地震产生超过历史观测最大近岸海啸高度的远源海啸的可能性增加。到2100年，在高排放代表性浓度路径（RCP8.5）的相对海平面上升预测下，产生大于1米最大近岸海啸高度所需的地震震级从约M9.1（目前所需）降至M8.0，而这个震级在阿拉斯加 - 阿留申俯冲带上出现的频率约为原来的6.7倍。
