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Evidence for diurnal periodicity of earthquakes from midnight to daybreak

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National Science Review 2019年第5期6卷 1016-1023页

作者： Jinlai Hao Jinhai Zhang zhenxing yao Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Previously, inadequate earthquake catalogs and the lack of method made it challenging, if not impossible, to determine the dominant period of earthquake *** the advent of densely distributed seismic stations in Japan since 2002, 410 642 M1.0+ earthquakes have been cataloged under the mainland within30-km depth, which provide a superb dataset to identify the periodicity of *** processed this catalog using time-frequency analyses and daily stacking, which are powerful in extracting weak periodical signal from strong random *** concentrated on the time sector from 0:00 to 6:00(*** midnight to daybreak), which is a reliable time window for much higher detectability of weak earthquakes,since it has the lowest affects from cultural *** successfully observed two apparent periodicities of12-and 24-hour, which are much smaller than the fortnightly periodicity presented previously in the *** earth tides, after intentionally ignoring the contribution from the Moon, present similar dominant periods as the *** may indicate that the dominant period of earthquakes is statistically associated with the Sun rather than the *** daily stacking number of earthquakes using a15-minute or 1-hour interval shows a peak around 1:30, rather than usually expected 3:00 to 4:*** addition, bigger earthquakes show more evident variations in the stacking results, and the trend is very consistent for various lower limits of earthquake magnitude from M1.0 to *** discoveries settled the disputes on the existence of the periodicity of earthquakes since 1886 and may open a window to unravel the mystery of earthquakes.

关键词： periodicity of earthquakes time-frequency analyses ocean tide earth tide Local Mean Time

Rupture process of the 2015 Pishan earthquake from joint inversion of InSAR, teleseismic data and GPS

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Science China Earth Sciences 2018年第10期61卷 1467-1481页

作者： Xun WANG Weimin WANG Junmeng ZHAO zhenxing yao Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Research Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

An earthquake of Mw6.4 occurred in Pishan County in Xinjiang Province, northwestern Tibetan Plateau, on July 3,2015. The epicenter was located on an active blind thrust system located at the northern margin of the Western Kunlun Mountain Orogenic Belt southwest of the Tarim Basin. We constructed a shovel-shaped fault model based on the layered-crust model with reference to the seismic reflection profile, and obtained the rupture process of the earthquake from the joint inversion of Interferometric Synthetic Aperture Radar(InSAR) measurements, far-field waveform data, and Global Positioning System(GPS) data. The results show that the seismic fault dips southward with a strike of 109°, and the rupture direction was essentially northward. The fault plane rupture distribution is concentrated, with a maximum recorded slip of 73 cm. The main features of the fault are as follows: low inclination angle(25°–10°), thrust slip at a depth of 9–13 km, rupture propagation time of about 12 s, no significant slip in soft or hard sedimentary layers at 0–4 km depth and propagation from the initial rupture point to the surrounding area with no obvious directionality. The InSAR time-series analysis method is used to determine the deformation rate in the source region within 2 years after the earthquake, and the maximum value is ~17 mm yr-1 in the radar line-of-sight direction. Obvious post-earthquake deformation is evident in the hanging wall, with a similar trend to the coseismic displacement field. These results suggest that the Pishan earthquake has not completely released the accumulated energy of the region, given that the multilayer fold structure above the blind fault is still in a process of slow uplift since the earthquake. Post-earthquake adjustment models and aftershock risk analysis require further study using more independent data.

关键词： Pishan earthquake Source process Joint inversion Post-earthquake deformation

Comparison of UV-based advanced oxidation processes for the removal of different fractions of NOM from drinking water

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Journal of Environmental Sciences 2023年第4期126卷 387-395页

作者： zhenxing yao Mingquan Wang Ruibao Jia Qinghua Zhao Li Liu Shaohua Sun Shandong Province City Water Supply and Drainage Water Quality Monitoring Center Jinan 250101China

This study examined the effectiveness for degradation of hydrophobic (HPO),transphilic(TPI) and hydrophilic (HPI) fractions of natural organic matter (NOM) during UV/H_(2)O_(2),UV/TiO_(2)and UV/K2S2O8(UV/PS) advanced oxidation processes (AOPs).The changing characteristics of NOM were evaluated by dissolved organic carbon (DOC),the specific UV absorbance (SUVA),trihalomethanes formation potential (THMFP),organic halogen adsorbable on activated carbon formation potential (AOXFP) and parallel factor analysis of excitation–emission matrices (PARAFAC-EEMs).In the three UV-based AOPs,HPI fraction with low molecular weight and aromaticity was more likely to degradate than HPO and TPI,and the removal efficiency of SUVA for HPO was much higher than TPI and HPI *** terms of the specific THMFP of HPO,TPI and HPI,a reduction was achieved in the UV/H_(2)O_(2)process,and the higest removal rate even reached to 83%.UV/TiO_(2)and UV/PS processes can only decrease the specific THMFP of *** specific AOXFP of HPO,TPI and HPI fractions were all able to be degraded by the three UV-based AOPs,and HPO content is more susceptible to decompose than TPI and HPI ***/H_(2)O_(2)was found to be the most effective treatment for the removal of THMFP and AOXFP under given conditions.C1 (microbial or marine derived humic-like substances),C_(2) (terrestrially derived humic-like substances)and C_(3) (tryptophan-like proteins) fluorescent components of HPO fraction were fairly labile across the UV-based AOPs treatment.C_(3) of each fraction of NOM was the most resistant to degrade upon the UV-based *** from this study may provide the prediction about the consequence of UV-based AOPs for the degradation of different fractions of NOM with varied characteristics.

关键词： Advanced oxidation processes Natural organic matter Trihalomethanes Organic halogen adsorbable on activated carbon Parallel factor analysis

Source process of the 2011 M_w9.0 Tohuko Japan earthquake

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Science China Earth Sciences 2011年第8期54卷 1105-1109页

作者： HAO JinLai WANG WeiMin yao zhenxing Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100085China Key Laboratory of Continental Collision and Plateau Uplift Chinese Academy of SciencesBeijing 100085China

On March 11, 2011, a magnitude Mw9.0 earthquake occurred near the east coast of Honshu, Japan, at 13：46 （Beijing time）, with an epicenter at 38.321°N, 142.369°E and a source depth of 24 km, as determined by the United States Geological Survey （USGS）（http：//***/ earthquakes/eqinthenews/）. A great tsunami then battered the northeast coast of Japan after the earthquake. The wave reached a maximum height of 23.6 m in some areas （http：//***/w/2011-03-24/***）. The earthquake also resulted in damage to a nuclear power plant in Fukushima that generated nuclear leakage. The earthquake, tsunami and nuclear leakage have brought about huge economic losses and casualties.

关键词：地震发生震源过程日本美国地质调查局北京时间震源深度 USGS 最大高度

Experimental and theoretical investigation on degradation of dimethyl trisulfide by ultraviolet/peroxymonosulfate: Reaction mechanism and influencing factors

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Journal of Environmental Sciences 2023年第5期127卷 824-832页

作者： Jianing Sun Xiaodong Xin Shaohua Sun Zhenqi Du zhenxing yao Mingquan Wang Ruibao Jia Shandong Province Water Supply and Drainage Monitoring Center Jinan 250101China School of Water Conservancy and Environment University of JinanJinan 250022China State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China

With a large amount of domestic sewage and industrial wastewater discharged into the water bodies,sulfur-containing organicmatter inwastewater produced volatile organic sulfide,such as dimethyl trisulfide(DMTS)throughmicroorganisms,caused the potential danger of drinking water safety and human *** present,there is still a lack of technology on the removal of *** this study,the ultraviolet/peroxymonosulfate(UV/PMS)advanced oxidation processes was used to explore the degradation of *** than 90%of DMTS(30μg/L)was removed under the conditions of the concentration ratio of DMTS to PMS was 3:40,the temperature(T)was 25±2℃,and 10 min of irradiation by a 200 W mercury lamp(365 nm).The kinetics rate constant k of DMTS reacting with hydroxyl radical(HO·)was determined to be 0.2477 min^(−1).Mn^(2+),Cu^(2+)and NO_(3)^(-)promoted the degradation of DMTS,whereas humic acid and Cl-in high concentrations inhibited the degradation *** chromatography-mass spectrometry was used to analyze the degradation products and the degradation intermediates were dimethyl disulfide and *** functional theory was used to predict the possible degradation mechanism according to the frontier orbital theory and the bond breaking mechanism of organic *** results showed that the S–S,C–S and C–H bonds in DMTS molecular structure were prone to fracture in the presence of free radicals,resulting in the formation of alkyl radicals and sulfur-containing radicals,which randomly combined to generate a variety of degradation products.

关键词： Ultraviolet/peroxymonosulfate Dimethyl trisulfide Products Density functional theory Degradation mechanism

Seismic characteristics of the 15 February 2013 bolide explosion in Chelyabinsk, Russia

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Earth and Planetary Physics 2018年第5期2卷 420-429页

作者： Zhi Wei LianFeng Zhao XiaoBi Xie JinLai Hao zhenxing yao Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100029 China Institute of Geophysics and Planetary Physics University of California at Santa Cruz California USA

The seismological characteristics of the 15 February 2013 Chelyabinsk bolide explosion are investigated based on seismograms recorded at 50 stations with epicentral distances ranging from 229 to 4324 km. By using 8–25 s vertical-component Rayleigh waveforms,we obtain a surface-wave magnitude of 4.17±0.31 for this event. According to the relationship among the Rayleigh-wave magnitude,burst height and explosive yield, the explosion yield is estimated to be 686 kt. Using a single-force source to fit the observed Rayleigh waveforms, we obtain a single force of 1.03×10^(12) N, which is equivalent to the impact from the shock wave generated by the bolide explosion.

关键词： Rayleigh-wave magnitude yield estimation focal mechanism the 15 February 2013 Chelyabinsk bolide

利用区域地震资料监测朝鲜地下核试验的研究进展

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地球与行星物理论评（中英文） 2025年第2期56卷 148-156页

作者：赵连锋谢小碧何熹张蕾杨庚姚振兴中国科学院地质与地球物理研究所地球与行星物理重点实验室北京100029 美国加州大学圣克鲁兹分校地球物理与行星物理研究所圣克鲁兹CA 95064

根据朝鲜6次地下核试验在中国东北及邻近地区产生的宽频带区域地震资料,中国科学院地质与地球物理研究所地震学学科组发展了一套用于监测地下核试验的地震学方法,主要包括震级测量和当量估计、高精度震中定位以及爆炸与天然地震事件识别... 详细信息

根据朝鲜6次地下核试验在中国东北及邻近地区产生的宽频带区域地震资料,中国科学院地质与地球物理研究所地震学学科组发展了一套用于监测地下核试验的地震学方法,主要包括震级测量和当量估计、高精度震中定位以及爆炸与天然地震事件识别等.在全球范围内,存在多个用于震级-当量转换的经验公式,确定何种公式适合于朝鲜半岛地区至关重要.通过搜集一组用于地震测深的化学爆炸的当量和埋深,并以这些已知爆炸源作为量规事件,能够标定朝鲜地下核试验场的震级-当量关系,从而实现对朝鲜地下核爆进行当量估计.在精确定位方面,发展了利用多事件之间波形互相关方法精确测定它们之间的走时差从而完成高精度相对震中定位.通过进一步利用Pn和Pg等多震相数据还实现了对核爆深度的相对定位.在爆炸震源识别方面,利用统计处理方法分析研究了不同类型事件所产生地震波的特征,包括6次地下核试验、4次天然地震和3次化学爆炸,以及一些矿区塌陷等.结果发现P和S类型波的振幅比,例如Pn/Lg、Pg/Lg和Pn/Sn等,在2 Hz以上能够较好区分各类震源.其中爆炸震源产生的振幅比显著高于天然地震的值.特别是,通过计算谱振幅比的台网平均值能够显著提高识别的可靠性.利用中国东北和附近地区地震台网所提供的数据可以准确地将朝鲜地下核试验从周边天然地震事件中识别出来.该方法同时得到化学爆炸的P/S谱振幅比值介于核爆炸和天然地震的群组之间.

关键词：爆炸当量估计震源相对定位爆炸和天然地震识别朝鲜地下核试验

Rupture process of the M_w7.9 Nepal earthquake April 25, 2015

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Science China Earth Sciences 2015年第9期58卷 1895-1900页

作者： WANG WeiMin HAO JinLai HE JianKun yao zhenxing Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Research Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

On April 25, 2015, a magnitude Mw7.9 earthquake occurred in the southern Himalaya, Nepal, at 14：11 local time （UTC 2015-04-25 06：11）.

关键词：尼泊尔破裂过程地震喜马拉雅 UTC

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Exact local refinement using Fourier interpolation for nonuniformgrid modeling

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Earth and Planetary Physics 2017年第1期1卷 58-62页

作者： JinHai Zhang zhenxing yao Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Numerical solver using a uniform grid is popular due to its simplicity and low computational cost, but would be unfeasible in the presence of tiny structures in large-scale media. It is necessary to use a nonuniform grid, where upsampling the wavefield from the coarse grid to the fine grid is essential for reducing artifacts. In this paper, we suggest a local refinement scheme using the Fourier interpolation, which is superior to traditional interpolation methods since it is theoretically exact if the input wavefield is band *** interpolation methods would fail at high upsampling ratios(say 50); in contrast, our scheme still works well in the same situations, and the upsampling ratio can be any positive integer. A high upsampling ratio allows us to greatly reduce the computational burden and memory demand in the presence of tiny structures and large-scale models, especially for 3D cases.

关键词： local refinement varying grid tiny structures fourier interpolation nonuniform grid