Frequency-Magnitude Characteristics Down to Magnitude-4.4 for Induced Seismicity Recorded at Mponeng Gold Mine, South Africa
Frequency-Magnitude Characteristics Down to Magnitude-4.4 for Induced Seismicity Recorded at Mponeng Gold Mine, South Africa
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DOI：
10.1785/0120090277
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发表时间：
2010-06-01
影响因子：
3
通讯作者：
Dresen, G.
中科院分区：
文献类型：
--
作者：
Kwiatek, G.;Plenkers, K.;Dresen, G.
本文旨在研究南非Mponeng矿对高频敏感的地震网络记录的微震目录的频率-震级特征和震级下限。该网络由一个三分量加速度计和八个声发射传感器组成，位于地表以下3.5公里深处，覆盖面积有限，约为300 x300 x300米。三分量加速度计被用于估计由网络良好记录的有限数量的135个事件（M-w范围从-4.1到-0.3）的矩震级。我们使用从加速度计数据估计的矩量与从声发射传感器估计的辐射能量/矩量之间的关系来将目录扩展到较低的幅度。的完整性的幅度选定的时空子集的目录估计。(1)一个余震序列的M-W 1.9的事件，发生在大约30米的网络，和（2）后爆破活动在工作日，位于超过80米的网络。数据遵循Gutenberg-Richter（GR）频率-震级关系，余震序列在M-w -4.4和-1.9之间，爆破后数据集在-3.5和-1.5之间，与地震活动性的自相似行为没有明显的偏差。我们估计所选子集的完整性的大小低至-4.3（B = 1.26）的余震序列和-3.4（B = 1.17）的爆破后活动。完整程度的差异归因于记录活动的位置和场地效应。
This article aims to investigate the frequency-magnitude characteristics and lower magnitude limits of the microseismic catalog recorded with a seismic network sensitive to high frequencies at Mponeng mine, South Africa. The network, composed of one three-component accelerometer and eight acoustic emission sensors, is located at a depth of 3.5 km below the surface and covers the limited volume of approximately 300 x 300 x 300 m. The three-component accelerometer was used to estimate the moment magnitude for the limited number of 135 events (M-w ranged from -4.1 to -0.3) well recorded by the network. We use the relation between the moment magnitude estimated from accelerometer data and radiated energy/moment magnitude estimated from acoustic emission sensors to extend the catalog to lower magnitudes. The magnitude of completeness of selected spatiotemporal subsets of the catalog was estimated for.(1) an aftershock sequence of an M-w 1.9 event that occurred approximately 30 m from the network, and (2) postblasting activity during working days, located more than 80 m from the network. The data follow the Gutenberg-Richter (GR) frequency-magnitude relationship with no visible deviation from self-similar behavior of seismicity between M-w -4.4 and -1.9 for the aftershock sequence and between -3.5 and -1.5 for the postblasting dataset. We estimated the magnitude of completeness of selected subset as low as -4.3 (b = 1.26) for the aftershock sequence and -3.4 (b = 1.17) for the postblasting activity. Differences in magnitude of completeness are attributed to location of recorded activity and site effects.