Estrada F, González-Vida J M, Peláez J A, Galindo-Zaldívar J, Ortega S, Macías J, Vázquez J T, Ercilla G
Institut de Ciències del Mar, CSIC., 08003, Barcelona, Spain.
Departamento de Matemática Aplicada, Escuela Politécnica Superior, Universidad de Málaga, 29071, Málaga, Spain.
Sci Rep. 2021 Aug 10;11(1):16253. doi: 10.1038/s41598-021-95729-6.
Tsunamis are triggered by sudden seafloor displacements, and usually originate from seismic activity at faults. Nevertheless, strike-slip faults are usually disregarded as major triggers, as they are thought to be capable of generating only moderate seafloor deformation; accordingly, the tsunamigenic potential of the vertical throw at the tips of strike-slip faults is not thought to be significant. We found the active dextral NW-SE Averroes Fault in the central Alboran Sea (westernmost Mediterranean) has a historical vertical throw of up to 5.4 m at its northwestern tip corresponding to an earthquake of Mw 7.0. We modelled the tsunamigenic potential of this seafloor deformation by Tsunami-HySEA software using the Coulomb 3.3 code. Waves propagating on two main branches reach highly populated sectors of the Iberian coast with maximum arrival heights of 6 m within 21 and 35 min, which is too quick for current early-warning systems to operate successfully. These findings suggest that the tsunamigenic potential of strike-slip faults is more important than previously thought, and should be taken into account for the re-evaluation of tsunami early-warning systems.
海啸由海底突然位移引发，通常源自断层处的地震活动。然而，走滑断层通常被视为次要触发因素，因为人们认为它们只能产生适度的海底变形；因此，走滑断层末端垂直落差的海啸生成潜力被认为并不显著。我们发现，位于阿尔沃兰海中部（地中海最西端）的右旋西北 - 东南向阿威罗伊斯活动断层在其西北端有高达5.4米的历史垂直落差，对应一次里氏震级7.0的地震。我们使用库仑3.3代码，通过海啸 - HySEA软件对这种海底变形的海啸生成潜力进行了模拟。在两个主要分支上传播的海浪在21至35分钟内到达伊比利亚海岸人口密集地区，最大到达高度为6米，这对当前的早期预警系统来说太快了，以至于无法成功运行。这些发现表明，走滑断层的海啸生成潜力比之前认为的更为重要，在重新评估海啸早期预警系统时应予以考虑。
