Using Waveform Cross Correlation for Detection, Location, and Identification of Aftershocks of the 2017 Nuclear Explosion at the North Korea Test Site

High‐Precision Relocation With the Burial Depths of the North Korean Underground Nuclear Explosions by Combining Pn and Pg Differential Traveltimes

“…Based on the above analysis and previous studies (e.g., Gibbons et al., 2017; He et al., 2018; Murphy et al., 2013; Myers et al., 2018; Schaff et al., 2018; Selby, 2010; Tian et al., 2018; Tibuleac et al., 2008; Wen & Long, 2010; Zhang & Wen, 2013; Zhao et al., 2014, 2016, 2017), we constructed a relative location system based on the DTTs from both Pg and Pn waves where ; ; , , , and are vectors composed of the longitudes, latitudes, origin times and depths, respectively, of a group of seismic events to be determined, and the superscript denotes the transpose. is a vector composed of the observed DTTs and of Pg and Pn waves, respectively.…”

“…Based on the above analysis and previous studies (e.g., Gibbons et al, 2017;He et al, 2018;Murphy et al, 2013;Myers et al, 2018;Schaff et al, 2018;Selby, 2010;Tian et al, 2018;Tibuleac et al, 2008;Wen & Long, 2010;Zhang & Wen, 2013;Zhao et al, 2014Zhao et al, , 2017, we constructed a relative location system based on the DTTs from both Pg and Pn waves…”

“…Relative location methods have frequently been used to provide accurate epicenters relative to a reference event for a group of closely distributed sources such as aftershock sequences or nuclear explosions. Accordingly, this approach has been successfully applied to obtain the relative locations of the NKTS nuclear explosions (e.g., Gibbons et al., 2017; He et al., 2018; Murphy et al., 2013; Schaff et al., 2018; Selby, 2010; Tian et al., 2018; Tibuleac et al., 2008; Wen & Long, 2010; Zhang & Wen, 2013; Zhao et al., 2014, 2016, 2017). However, most of these relative location methods do not provide satisfactory information on the burial depth due to the strong trade‐off between the burial depth and origin time (e.g., Waldhauser & Ellsworth, 2000; Zhao et al., 2014).…”

Optimization of the Match‐Filtering Method for Robust Repeating Earthquake Detection: The Multisegment Cross‐Correlation Approach

“…Instead, we could consider the time‐bandwidth product of the seismogram that characterizes the amount of information contained in the signal to determine the optimal bandwidth. With a larger time‐bandwidth product, i.e., longer signal duration and wider frequency bandwidth, the cross‐correlation can be of greater statistical significance (Schaff, 2008; Schaff et al, 2018).…”

Support Vector Machine Classification of Seismic Events in the Tianshan Orogenic Belt

“…Discriminating between these various types of events is of significant scientific and societal importance. For example, event discrimination has been a major scientific endeavor in nuclear explosion monitoring (e.g., Fisk, ; Hartse et al, ; He et al, ; Kim et al, ; Kim et al, ; Richards & Kim, ; Schaff et al, ; Tian et al, ; Walter et al, ; Wang et al, ; Xie & Patton, ; Yao, Tian, Lu, et al, ; Yao, Tian, Sun, & Wen, ; Zhang & Wen, , ; Zhao et al, ); classifications of anthropogenic earthquake activities, such as those related to water impoundment of a reservoir (e.g., Do Nascimento et al, ; Ge et al, ; Gough & Gough, ; Guha, ), energy field production (e.g., Clarke et al, ; Guilhem et al, ; Hough & Page, ; Šílený et al, ; Tang et al, ), and waste water injection (e.g., Keranen et al, ; Langenbruch & Zoback, ), have attracted significant interests in the scientific community and the public; and in the seismic hazard analysis, identification of the seismic events that are unrelated to the tectonic process, such as quarry blasts (QBs) or IEs, is also necessary, as their presence in the seismic event catalog would lead to erroneous analyses of seismic hazard.…”