Seismically-induced mass movements and volumetric fluxes resulting from the 2010 Mw=7.2 earthquake in the Sierra Cucapah, Mexico
Seismically-induced mass movements and volumetric fluxes resulting from the 2010 Mw=7.2 earthquake in the Sierra Cucapah, Mexico
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DOI：
10.1016/j.geomorph.2014.11.012
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发表时间：
2015-02-01
期刊：
影响因子：
3.9
通讯作者：
Wright, Tim
中科院分区：
文献类型：
--
作者：
Barlow, John;Barisin, Ivana;Wright, Tim
观察到，受到高震级地震袭击的山脉的沉积物通量可能会受到同震质量运动的强烈影响，这一观察结果质疑了同震变形作为造山净贡献者的性质。为了更好地限制高震级地震在造山作用中的作用，需要针对不同构造、地形和气候环境的地区提供高分辨率的地震造成的质量损失数据。在这里，我们将侵蚀通量与2010年墨西哥M-W=72 El Mayor地震相关的构造通量进行比较，并研究与此事件相关的同震质量运动的滑坡模式。断裂断裂系统具有明显的走滑成分，沿东翼下沉，西侧隆升。地表加速度峰值沿坡度最大的地段最大，因此滑坡的发生频率与坡度密切相关，垂直和水平同震位移对滑坡的起始具有很强的控制作用。这一结果表明，走滑系统在地震期间经历了与逆冲断层截然不同的滑坡模式。根据对合成孔径雷达图像的干涉分析，地震造成的总隆起体积为41.6×10(6)m(3)，由于下沉造成的损失为952×10(6)m(3)。这表明净构造体积通量为-53.6×10(6)m(3)。同震滑坡引起的泥沙移动量估计为-2.7×10(6)m(3)，这是从使用SPOT 5多光谱图像的手工绘制的清单中得出的。因此，山脉的同震下沉造成的净体积损失产生了强烈的负质量通量，而质量损耗只是略微增加了质量通量。(C)2014爱思唯尔B.V.保留所有权利。
The observation that sediment flux from mountain ranges struck by high magnitude earthquakes can be strongly influenced by coseismic mass movements brings into question the nature of coseismic deformation as a net contributor to mountain building. To better constrain the role of high-magnitude earthquakes in orogenesis, high-resolution data of earthquake induced mass wasting is required for areas of differing tectonic, morphological, and climatic settings. Here we compare the erosional flux to the tectonic flux associated with the 2010 M-W = 72 Sierra El Mayor earthquake in Mexico and examine the landslide patterning of coseismic mass movements associated with this event. The ruptured fault system has a significant strike-slip component with subsidence along the eastern flank and uplift on the western flank of the range. Peak ground acceleration was highest along the steepest sections of the range such that the frequency of landslide occurrence was strongly correlated to slope gradient Both vertical and horizontal coseismic displacement demonstrated a strong control over land-slide initiation. This result suggests that strike-slip systems experience very different landslide patterning to thrust faults during earthquakes. Based on interferometric analysis of synthetic aperture radar images, the earthquake resulted in a total uplifted volume of 41.6 x 10(6) m(3) and a loss of 952 x 10(6) m(3) due to subsidence. This suggests a net tectonic volumetric flux of -53.6 x 10(6) m(3). Sediment mobilisation by coseismic landslides is estimated at -2.7 x 10(6) m(3) derived from a manually mapped inventory using SPOT 5 multispectral imagery. Thus, the net volume loss through coseismic subsidence of the mountain range generated a strongly negative mass flux, which was only marginally enhanced by mass wasting. (C) 2014 Elsevier B.V. All rights reserved.