Blackwell Em, Shirzaei Manoochehr, Ojha Chandrakanta, Werth Susanna
School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA.
School of Geography and Urban Planning, Arizona State University, Tempe, AZ, USA.
Sci Adv. 2020 Jul 31;6(31):eaba4551. doi: 10.1126/sciadv.aba4551. eCollection 2020 Jul.
Coastal vertical land motion affects projections of sea-level rise, and subsidence exacerbates flooding hazards. Along the ~1350-km California coastline, records of high-resolution vertical land motion rates are scarce due to sparse instrumentation, and hazards to coastal communities are underestimated. Here, we considered a ~100-km-wide swath of land along California's coast and performed a multitemporal interferometric synthetic aperture radar (InSAR) analysis of large datasets, obtaining estimates of vertical land motion rates for California's entire coast at ~100-m dimensions-a ~1000-fold resolution improvement to the previous record. We estimate between 4.3 million and 8.7 million people in California's coastal communities, including 460,000 to 805,000 in San Francisco, 8000 to 2,300,00 in Los Angeles, and 2,000,000 to 2,300,000 in San Diego, are exposed to subsidence. The unprecedented detail and submillimeter accuracy resolved in our vertical land motion dataset can transform the analysis of natural and anthropogenic changes in relative sea-level and associated hazards.
沿海垂直地面运动影响海平面上升预测，而地面沉降会加剧洪水灾害。在约1350公里长的加利福尼亚海岸线上，由于仪器设备稀疏，高分辨率垂直地面运动速率记录稀缺，沿海社区面临的灾害被低估。在此，我们考虑了加利福尼亚海岸沿线约100公里宽的地带，对大型数据集进行了多时相干涉合成孔径雷达（InSAR）分析，获得了加利福尼亚整个海岸约100米尺度的垂直地面运动速率估计值——比之前的记录分辨率提高了约1000倍。我们估计，加利福尼亚沿海社区有430万至870万人面临地面沉降风险，其中旧金山有46万至80.5万人，洛杉矶有8000至230万人，圣地亚哥有200万至230万人。我们垂直地面运动数据集中前所未有的细节和亚毫米精度可以改变对相对海平面自然和人为变化及相关灾害的分析。
