SUMMARY

A sequence of earthquake events consisting of three large shocks occurred in Central Italy from August to October in 2016 with the duration of almost 2 months. The preliminary study on the seismic mechanism suggests that the sequence of events is the result from the activity of the SW dipping Mt Bove–Mt Vettore–Mt Gorzano normal fault system. For investigation and understanding of the coseismic faulting of the seismogenic fault alignment, we collect a set of comprehensive satellite observations including the Sentinel-1A, ALOS-2/PALSAR-2 and GPS data to map the coseismic surface deformation and estimate the source models in this study. The derived faulting model for the first Amatrice event is characterized by two distinct slip asperities suggesting that it is a predominantly normal dip-slip motion with slight strike-slip component. The second event, Visso earthquake is almost a purely normal rupture. The third Norcia event is dominated by the normal dip-slip rupture of the seismogenic fault, and has propagated up to the ground with significant slip. The three faulting models are then utilized to quantify the Coulomb failure stress (CFS) change over the seismic zone. First, the CFS change on the subsequent two seismogenic faults of the earthquake sequence is estimated, and the derived positive CFS change induced by the preceding earthquakes suggests that the early events have positive effects on triggering the subsequent seismicity. We then explore the response relation of the aftershocks including 961 events with magnitudes larger than M 3.0 to the CFS change over the seismic zone. It suggests that the rupture pattern of the aftershocks is similar to the major shocks with predominantly normal dip-slip. To assess the risk of the future seismic hazard, we analyse quantitatively the spatial distribution of aftershock occurrence and CFS transfer at the seismogenic depth, indicating that the ruptures of the three major shocks do partly release the accumulated strain on the associated fault alignment as well as the dense aftershock, but the CFS increase zone with few aftershocks in the southwest of the eastern Quaternary fault alignment of Central Italy poses the potential of further rupture. In particular, the distribution of aftershock migration also suggests that the north extension of the Mt Bove fault is the potential zone with rupture risk.

中文翻译：

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使用多源卫星观测和库仑应力变化的定量评估对2016年意大利中部地震群进行顺序建模

概要

2016年8月至10月，意大利中部发生了一系列由三场大地震组成的地震事件，持续时间将近2个月。对地震机制的初步研究表明，事件的顺序是西南部浸没的Bove–Mett Vettore–Mt Gorzano正断层系统活动的结果。为了调查和理解成地震断层对准的同震断层，我们收集了一套综合的卫星观测资料，包括Sentinel-1A，ALOS-2 / PALSAR-2和GPS数据，以绘制同震表面变形的图并估算震源断层的震源模型。这项研究。首次Amatrice事件的导出断层模型的特征是两个明显的滑动凹凸，表明它主要是正常的俯冲滑动运动，带有轻微的走滑分量。第二件事，维索地震几乎是纯粹的正常破裂。第三次诺尔恰事件主要由发震断层的正常倾滑破裂引起，并以明显的滑移传播到地面。然后使用这三个断层模型来量化整个地震带上的库仑破坏应力（CFS）变化。首先，估算了地震序列随后两个地震断层的CFS变化，并且推导了由先前地震引起的正CFS变化，表明早期事件对触发后续地震活动具有积极影响。然后，我们探索了余震，包括961个事件（其大小大于M 3.0）对地震带CFS变化的响应关系。这表明余震的破裂模式与以正常倾滑为主的主要冲击相似。为了评估未来地震危险的风险，我们定量分析了在地震发生深度的余震发生和CFS传递的空间分布，这表明三大地震的破裂确实部分释放了相关断层走向上的累积应变以及意大利中部东部第四纪断层系西南部的余震密集，但CFS上升带几乎没有余震，这可能进一步破裂。特别是，余震运移的分布还表明，博夫山断裂的北延伸是具有破裂危险的潜在区域。我们定量分析了在地震发生深度的余震发生和CFS传递的空间分布，这表明三大地震的破裂确实部分释放了相关断层走向上的累积应变以及密集的余震，但是CFS增加了意大利中部东部第四纪断层系西南部的少量余震具有进一步破裂的可能。特别是，余震运移的分布还表明，博夫山断裂的北延伸是具有破裂危险的潜在区域。我们定量分析了在地震发生深度的余震发生和CFS传递的空间分布，这表明三大地震的破裂确实部分释放了相关断层走向上的累积应变以及密集的余震，但是CFS增加了意大利中部东部第四纪断层系西南部的少量余震具有进一步破裂的可能。特别是，余震运移的分布还表明，博夫山断裂的北延伸是具有破裂危险的潜在区域。表明三大地震的破裂确实部分地释放了相关断层走向和密集的余震的累积应变，但是意大利中部东部第四纪断层走向西南部的余震很少的CFS增大带具有潜在的潜力。进一步破裂。特别是，余震运移的分布还表明，博夫山断裂的北延伸是具有破裂危险的潜在区域。表明三大地震的破裂确实部分地释放了相关断层走向和密集的余震的累积应变，但意大利中部东部第四纪断层走向西南部的余震较少的CFS增大带具有潜在的潜力。进一步破裂。特别是，余震运移的分布还表明，博夫山断裂的北延伸是具有破裂危险的潜在区域。