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2010年1月12日的MW7.0海地地震发生在北美板块与加勒比板块交界的复杂形变区域。综合大地测量、地质和地震数据断定,地表变形是由莱奥甘逆冲盲断层破裂驱动的,而部分破裂为发生在恩里基约—普兰廷加登断层(EPGF)上的深侧向滑移。这次地震触发了至少4 490处滑坡,主要为浅层的扰动碎屑流、泥石—土质崩塌与滑落,以及一些侧向滑移,分布面积约为2 150km2。这些滑坡的区域分布特征与大部分类似的以前地震触发滑坡事件报告不同。大部分同震滑坡并没有发生在主破裂的上盘,而是聚集在莱奥甘盲破裂与恩里基约—普兰廷加登断层盲破裂的交汇处,这里的地形起伏和斜坡陡度均高于平均值。此外,遭受到高同震上升的低地形起伏区域倾向于比以往研究中认为的上盘更容易发生滑坡。我们认为复杂的破裂动力学与地形的综合影响主要控制了这种以前研究中很少记录的地震滑坡样式。对比近期其他地区相似震级的逆断型地震事件我们得出结论,2010年海地地震的较低静态应力降、平均断层位移和盲破裂导致了比以往研究表现出更少、更小和更对称的滑坡分布。我们的结果提醒不要过分依靠全面的边坡稳定性地震动响应模型。
The MW 7.0 Haiti earthquake on January 12, 2010 occurred in a complex deformation area at the intersection of the North American and Caribbean plates. Based on geodetic, geologic, and seismic data, the surface deformation was driven by the Leogane thrust blind fault rupture and the partial rupture was a deep lateral slip that occurred on the Enriki-Platon-Tyden fault (EPGF) . The quake triggered at least 4 490 landslides, mainly shallow disturbed debris flows, debris-soil collapse and slippage, and some lateral slip with an area of about 2 150 km2. The regional distribution of these landslides differs from the reports of most similar previous earthquakes triggered landslides. Most of the coseismic landslides did not occur in the main rupture of the upper plate, but rather converged at the junction of the Leogane blind rupture and the Enricquillo-Prandinden fault faulted blind rupture, where both the topography and slope steepness are high On average. In addition, low-relief areas subject to high cres- teismic upsets tend to be more prone to landslides than previous studies suggest. We believe that the combined effects of complex fracture dynamics and topography dominate the seismographic landslide patterns rarely documented in previous studies. In contrast to recent reverse seismic events of similar magnitude in other regions, we conclude that the lower static stress drop, mean fault displacement and blind rupture of the Haiti earthquake in 2010 led to fewer, smaller and more symmetrical than previous studies Landslide distribution. Our results warn against over-reliance on a comprehensive slope stability response model to ground motion.