Source characteristics and dynamics of the October 2018 Baige landslide revealed by broadband seismograms
Source characteristics and dynamics of the October 2018 Baige landslide revealed by broadband seismograms
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DOI：
10.1007/s10346-019-01145-3
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发表时间：
2019-02
期刊：
影响因子：
6.7
通讯作者：
Zhen Zhang;Si-ming He;Wei Liu;Heng Liang;Shuai-xing Yan;Yu Deng;Xiuqiang Bai;Zheng Chen
中科院分区：
文献类型：
--
作者：
Zhen Zhang;Si-ming He;Wei Liu;Heng Liang;Shuai-xing Yan;Yu Deng;Xiuqiang Bai;Zheng Chen
北京时间2018年10月10日22时05分36秒（UTC+8），中国西藏自治区境内发生特大白格滑坡灾害。这次大规模快速滑坡产生了强烈的长周期地震信号，这些信号被宽频带地震台站记录下来。在这项研究中，我们从距离事件108至255公里的5个宽带地震台站反演了长周期地震数据，以获得滑坡对地球施加的力的时间序列。然后，我们计算了由事件产生的地震信号的垂直分量的频谱图，记录在最近的宽带地震台站（GZI）。该谱图结合力-时间函数和现场调查，描述了滑坡的动力学过程，可分为三个阶段。对于第一个时间间隔，假设岩滑可以被视为一个滑块，我们估计的平均边坡平行的滑动材料的加速度为1.08米/秒2，在岩滑的基础上的平均摩擦系数为0.47。在第二和第三个间隔，岩石滑坡已转化为粒状碎屑。力的方向和定时对应于颗粒状碎屑的滑动路径中的不同点。我们利用这种相关性来估计颗粒状碎片的速度。研究表明，滑坡产生的地震信号提供了一种有效的方法来估计滑坡的动力特性。
The catastrophic Baige landslide occurred at 22:05:36 (Beijing time, UTC+8) on the 10th of October 2018 in Tibet, China. The large and rapid landslide generated strong long-period seismic signals that were recorded by broadband seismic stations. In this study, we inverted the long-period seismic data from five broadband seismic stations at distances of 108 to 255 km from the event to obtain a time series of forces that the landslide exerted on the Earth. Then, we calculated the spectrogram of the vertical component of the seismic signal generated by the event, recorded at the closest broadband seismic station (GZI). This spectrogram, combined with the force-time function and the field investigation, described the dynamic process of the landslide that could be divided into three intervals. For the first interval, assuming that the rockslide can be regarded as a sliding block, we estimated the average slope-parallel acceleration of the sliding materials at 1.08 m/s2, and the average friction coefficient at the base of the rockslide at 0.47. In the second and third intervals, the rockslide had converted to granular debris. The direction and timing of the force correspond to the different points in the sliding path of the granular debris. We used this correlation to estimate the speeds of the granular debris. This study demonstrates that the seismic signal generated by the landslide provides an effective method for estimating the dynamic properties of the landslide.