Abstract. The devastating Mw 7.1 Haiti earthquake in 2010 was accompanied by local tsunamis that caused fatalities and damage to coastal infrastructure. Some were triggered by slope failures of river deltas in the close vicinity of the epicenter, while others, 30 to 50 km to the north across the Bay of Gonâve, are well explained by the reverse component of coseismic ground motion that accompanied this mostly strike-slip event. However, observations of run-up heights up to 2 m along the southern coast of the island at distances up to 100 km from the epicenter, as well as tide gauge and DART buoy records at distances up to 600 km from the epicenter, have not yet received an explanation. Here we demonstrate that these observations require a secondary source, most likely a submarine landslide. We identify a landslide scar 30 km from the epicenter off the southern coast of Haiti at a depth of 3500 m, where ground acceleration would have been sufficient to trigger slope failure in soft sediments. This candidate source, 2 km 3 in volume, matches observations remarkably well assuming that the sediment collapse obeys a viscous flow with an initial apparent viscosity of 2×105 Pa s. Although that particular source cannot be proven to have been activated in 2010, our results add to a line of evidence that earthquake-triggered submarine landslides can cause significant tsunamis in areas of strike-slip tectonic regime.

中文翻译：

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深海底滑坡对 2010 年海地地震海啸的贡献

摘要。2010 年海地破坏性 Mw 7.1 地震伴随着当地海啸，造成人员死亡和沿海基础设施损坏。有些是由震中附近河流三角洲的斜坡破坏引发的，而另一些则是在戈纳韦湾以北 30 至 50 公里处，可以很好地解释为伴随这种主要是撞击的同震地面运动的反向分量滑倒事件。然而，在距震中 100 公里处对岛屿南部海岸高达 2 m 的爬升高度的观测，以及距震中 600 公里处的潮汐测量仪和 DART 浮标记录，都没有却得到了解释。在这里，我们证明这些观测需要二次来源，最有可能是海底滑坡。我们在距海地南部海岸震中 30 公里、深度为 3500 米的地方发现了一个滑坡疤痕，在那里地面加速度足以触发软沉积物中的斜坡崩塌。假设沉积物坍塌遵循初始表观粘度为 2×105 Pa s 的粘性流，这个体积为 2 km 3 的候选源与观测结果非常吻合。尽管无法证明该特定源在 2010 年已被激活，但我们的结果增加了一系列证据，即地震引发的海底滑坡可在走滑构造体系区域引起重大海啸。假设沉积物坍塌遵循初始表观粘度为 2×105 Pa s 的粘性流，则与观察结果非常吻合。尽管无法证明该特定源在 2010 年已被激活，但我们的结果增加了一系列证据，即地震引发的海底滑坡可在走滑构造体系区域引起重大海啸。假设沉积物坍塌遵循初始表观粘度为 2×105 Pa s 的粘性流，则与观察结果非常吻合。尽管无法证明该特定源在 2010 年已被激活，但我们的结果增加了一系列证据，即地震引发的海底滑坡可在走滑构造体系区域引起重大海啸。