谢小碧^1,,
赵连锋^2,3
1. 美国加州大学圣克鲁兹分校, 地球物理与行星物理研究所, 加州圣克鲁兹 95064
2. 中国科学院地质与地球物理研究所, 中国科学院地球与行星物理重点实验室, 北京 100029
3. 中国科学院地球科学研究院, 北京 100029

基金项目: 国家重点研发计划（2017YFC0601206）和国家自然科学基金（41674060，41374065，41630210）资助


详细信息

作者简介: 谢小碧.E-mail:xxie@ucsc.edu

中图分类号: P315

收稿日期:2017-11-02
修回日期:2018-01-16
上线日期:2018-03-05

The seismic characterization of North Korea underground nuclear tests

XIE XiaoBi^1,,
ZHAO LianFeng^2,3
1. Institute of Geophysics and Planetary Physics, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
2. Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
3. Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, China


MSC: P315

--> Received Date: 02 November 2017
Revised Date: 16 January 2018
Available Online: 05 March 2018


摘要
摘要:自2006年至2017年，朝鲜民主主义人民共和国在中朝边界地区的试验场进行了6次地下核试验.本文综合报道根据东北亚地区的宽频带数字地震资料利用地震学方法对这六次地下核爆炸的研究.结果表明，朝鲜地下核试验在区域台网产生的地震记录具有典型浅源爆炸的特征.针对上述资料发展了处理核爆数据的方法并据此得出各次朝鲜核爆的地震学参数，包括事件识别、当量测定、以及震中相对定位等.对6次核爆和4次天然地震P/S类型谱振幅比的统计分析表明，2 Hz以上台网平均谱振幅比可以正确地将朝鲜核爆从天然地震中识别出来，从而有效监测在朝鲜半岛进行的当量大于0.5 kt的地下核试验.同时也发现，建立在体波-面波震级比之上的识别方法不适用于朝鲜核试验场.通过建立中朝边界地区基于Lg波的体波震级系统，计算了各次朝鲜核试验的体波震级m_b（Lg），并由此估计了它们的地震学当量，其值介于0.5 kt至60 kt之间.由于缺少爆炸埋藏深度的数据，上述当量有可能被低估，因而有必要对深度影响做进一步研究.以第一次爆炸的位置为参考震中，利用Pn波相对走时数据和高精度相对定位方法获得了各次核爆在试验场中的精确定位.
关键词: 地下核试验/
识别/
定位/
当量估计/
朝鲜

Abstract:Since 2006, North Korea (DPRK) conducted 6 underground nuclear tests at the test site located near the China-North Korea border. These explosions generated abundant broad band digital seismograms within regional distances. These seismograms show typical features of shallow explosions. Processing methods for event discrimination, yield estimation, and relocation of epicenters were developed to investigate these explosions. The spectral ratios Pg/Lg, Pn/Lg, and Pn/Sn were calculated for all 6 explosions and 4 nature earthquakes. The results show that network averaged P/S type spectral ratios can unambiguously separate explosions from natural earthquakes. With this method, a regional network can effectively monitor nuclear tests of 0.5 kt or larger in the Korea Peninsula. The results also revealed that the m_b-M_S magnitude ratio cannot effectively discriminate the explosion and earthquake sources in this region. A body wave magnitude system based on regional phase Lg was created for the Northeast China-North Korea border region. Based on this method, the Lg wave magnitudes of these nuclear tests were calculated and their seismic yields were estimated ranging between 0.5 and 60 kt. Due to lack of depth of burial information, these yields may be underestimated. Further investigation of the depth effect on yield estimation is suggested. Using the location of the first nuclear test as a reference, the epicenters of other explosions were relocated using a high-precision relative location method.
Key words:Underground nuclear test/
Discrimination/
Relative location/
Yield estimation/
North Korea



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