近日，美国弗吉尼亚理工大学Tina Dura团队揭示地震引发的沉降和海平面上升后，太平洋西北部的洪水风险增加。2025年4月28日，《美国科学院院刊》发表了这一成果。

气候驱动的海平面上升正在增加全球沿海洪水的频率，局部地区因地下水和资源开采造成的地面沉降等因素而加剧。然而，在未来的海平面上升情景中很少考虑的一个过程是与大地震（>M8）相关的突然（几分钟内）地面沉降，大地震可能超过1米。在华盛顿州、俄勒冈州和加利福尼亚州北部海岸，下一次卡斯卡迪亚俯冲带大地震可能会导致高达2米的突然海岸沉降，大大提高海平面，扩大洪泛区，增加当地社区的洪水风险。

研究组量化了24个卡斯卡迪亚河口在低（~0.5米）、中（~1米）和高（~2米）地震驱动的沉降情景下1%漫滩（即年洪水风险为1%的区域）的潜在扩张。如果今天发生大地震，洪泛区可能会扩大90平方公里（低）、160平方公里（中）或300平方公里（高沉降），在高沉降情景下，居民、建筑物和道路的洪水风险将增加一倍以上。

到2100年，当气候驱动的海平面上升将加剧危险时，一场大地震可能会使洪泛区扩大170平方公里（低）、240平方公里（中）或370平方公里（高沉降），与2023年的洪泛区相比，在高沉降情景下，居民、建筑物和道路的洪水风险增加了两倍多。该研究结果可以为卡斯卡迪亚俯冲带沿线的决策者和沿海社区提供支持，因为他们为地震周期和气候驱动的海平面上升带来的复合危害做准备，并为全球构造活跃的海岸线提供关键见解。

附：英文原文

Title: Increased flood exposure in the Pacific Northwest following earthquake-driven subsidence and sea-level rise

Author: Dura, Tina, Chilton, William, Small, David, Garner, Andra J., Hawkes, Andrea, Melgar, Diego, Engelhart, Simon E., Staisch, Lydia M., Witter, Robert C., Nelson, Alan R., Kelsey, Harvey M., Allan, Jonathan C., Bruce, David, DePaolis, Jessica, Priddy, Michael, Briggs, Richard W., Weiss, Robert, La Selle, SeanPaul, Willis, Michael, Horton, Benjamin P.

Issue&Volume: 2025-4-28

Abstract: Climate-driven sea-level rise is increasing the frequency of coastal flooding worldwide, exacerbated locally by factors like land subsidence from groundwater and resource extraction. However, a process rarely considered in future sea-level rise scenarios is sudden (over minutes) land subsidence associated with great (>M8) earthquakes, which can exceed 1 m. Along the Washington, Oregon, and northern California coasts, the next great Cascadia subduction zone earthquake could cause up to 2 m of sudden coastal subsidence, dramatically raising sea level, expanding floodplains, and increasing the flood risk to local communities. Here, we quantify the potential expansion of the 1% floodplain (i.e., the area with an annual flood risk of 1%) under low (~0.5 m), medium (~1 m), and high (~2 m) earthquake-driven subsidence scenarios at 24 Cascadia estuaries. If a great earthquake occurred today, floodplains could expand by 90 km2 (low), 160 km2 (medium), or 300 km2 (high subsidence), more than doubling the flooding exposure of residents, structures, and roads under the high subsidence scenario. By 2100, when climate-driven sea-level rise will compound the hazard, a great earthquake could expand floodplains by 170 km2 (low), 240 km2 (medium), or 370 km2 (high subsidence), more than tripling the flooding exposure of residents, structures, and roads under the high subsidence scenario compared to the 2023 floodplain. Our findings can support decision-makers and coastal communities along the Cascadia subduction zone as they prepare for compound hazards from the earthquake cycle and climate-driven sea-level rise and provide critical insights for tectonically active coastlines globally.

DOI: 10.1073/pnas.2424659122

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2424659122