Spectral amplification of ground motion linked to resonance of large-scale mountain landforms
Spectral amplification of ground motion linked to resonance of large-scale mountain landforms
复制标题
与大规模山地地貌共振相关的地面运动频谱放大
DOI：
10.1016/j.epsl.2021.117295
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发表时间：
2022
影响因子：
5.3
通讯作者：
Moore, Jeffrey R.
中科院分区：
文献类型：
--
作者：
Weber, Samuel;Beutel, Jan;Häusler, Mauro;Geimer, Paul R.;Fäh, Donat;Moore, Jeffrey R.
陡峭地形上的地震能量放大对地震诱发滑坡的位置起着重要的控制作用。阿尔卑斯山代表着极端的地形，因此可以预期会有很大的放大，但需要合适的数据来探测这些要求苛刻的地点的地形影响的限度，这种情况很少见。在这里，我们展示了瑞士阿尔卑斯山中最高的独立山脉之一--马特宏峰--山顶和山脊上的地震台的最新环境振动数据，并将这些数据与附近的当地参考数据进行了比较。结果显示，山区台站的光谱功率在0.4至1赫兹之间升高，定向站点与参考站的光谱幅度比高达14，我们将其部分归因于地形共振。我们使用环境振动模态分析和数值特征频率建模来识别马特宏峰在0.42赫兹的基模，以及在相似频率下存在相互垂直的第二模的证据。我们发现这些模式的高模式阻尼率为∼的20%，我们将其归因于辐射能量损失。在另一座形状相似但尺度较小的山上进行的短期活动测量显示，类似的模式特性具有更高的基频1.8赫兹和峰值频谱比6。对马特宏峰一年来的共振频率的跟踪表明，与近地表环境变化(如温度、冰)有关的季节变化不明显。我们的结果表明，大光谱放大与高起伏山脉地貌的共振有关，这可能是一种广泛的影响，使这些地区更容易发生同震岩石破坏和山体滑坡。
Amplification of seismic energy in steep topography plays an important role controlling the location of earthquake-induced landslides. Alpine mountains represent extreme topography, therefore large amplification may be anticipated, however suitable data needed to probe the limits of topographic effects in these demanding locations are rare. Here we present new ambient vibration data from seismic stations on the summit and ridge of one of the tallest freestanding mountains in the Swiss Alps – the Matterhorn – comparing these to a nearby local reference. Results show elevated spectral power at mountain stations between 0.4 and 1 Hz, and directional site-to-reference spectral amplitude ratios up to 14, which we attribute in part to topographic resonance. We used ambient vibration modal analysis and numerical eigenfrequency modeling to identify the fundamental mode of the Matterhorn at 0.42 Hz, as well as evidence for a second, mutually-perpendicular mode at a similar frequency. We identified high modal damping ratios of ∼20% for these modes, which we ascribe to radiative energy loss. A short campaign measurement at another mountain of comparable shape but smaller scale showed similar modal properties with a higher fundamental frequency of 1.8 Hz and peak spectral ratios of 6. Tracking of resonant frequencies over one year at the Matterhorn revealed no measurable seasonal variations related to near-surface environmental changes (e.g. temperature, ice). Our results demonstrate large spectral amplifications linked to resonance of high-relief mountain landforms, which is likely to be a widespread effect making such areas more prone to co-seismic rock damage and landslides.
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影响因子：
5.3
作者：
R. Ambrosini
通讯作者：
R. Ambrosini
DOI：
--
发表时间：
1999
期刊：
--
影响因子：
--
作者：
M. Çelebi
通讯作者：
M. Çelebi
使用地震共振测量来确定独立岩体的弹性模量
影响因子：
6.2
作者：
J. Moore;Paul R. Geimer;R. Finnegan;M. Thorne
通讯作者：
M. Thorne
影响因子：
4.5
作者：
Michel, Clotaire;Gueguen, Philippe;Kotronis, Panagiotis
通讯作者：
Kotronis, Panagiotis
影响因子：
3.3
作者：
Edwards, Benjamin;Michel, Clotaire;Faeh, Donat
通讯作者：
Faeh, Donat