{"title":"Hypocenter uncertainty analysis of induced and tectonic earthquakes in the Netherlands","authors":"Jesper Spetzler, Elmer Ruigrok, Dagmar Bouwman","doi":"10.1007/s10950-024-10205-8","DOIUrl":null,"url":null,"abstract":"<div><p>Induced earthquakes tend to be shallow, while tectonic events often occur in deeper parts of the Earth. A well-estimated hypocenter with uncertainties may help to evaluate whether an event is of an induced or tectonic origin. In this study, we focus on the development of a hypocenter method that helps to better define the source location of an earthquake and reduce the spatial error of the measurement. The hypocenter and the uncertainty is obtained by using the P- and S-wave phase time difference for a station and the P-wave traveltime differences between pairs of stations simultaneously in the hypocenter analysis. The uncertainty inherent to an imperfect reference velocity model, modelling, instrumental inaccuracy and phase time picking is propagated into the spacial hypocenter solution. A refined hypocenter methodology is successfully tested in a synthetic experiment with shallow (<span>\\(\\sim \\)</span> 5 km), intermediate (<span>\\(\\sim \\)</span> 10 km) and deep source points (<span>\\(\\sim \\)</span> 15 km). The synthetic experiment indeed shows that it is possible to separate earthquakes by their depth solution, hence offering an indication that the event is either induced or tectonic. Case studies are presented of estimations of hypocenters and error ellipses for (1) induced seismicity at sites for gas storage in salt domes, geothermal production and gas extraction as well as (2) tectonic events.</p></div>","PeriodicalId":16994,"journal":{"name":"Journal of Seismology","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Seismology","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1007/s10950-024-10205-8","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Induced earthquakes tend to be shallow, while tectonic events often occur in deeper parts of the Earth. A well-estimated hypocenter with uncertainties may help to evaluate whether an event is of an induced or tectonic origin. In this study, we focus on the development of a hypocenter method that helps to better define the source location of an earthquake and reduce the spatial error of the measurement. The hypocenter and the uncertainty is obtained by using the P- and S-wave phase time difference for a station and the P-wave traveltime differences between pairs of stations simultaneously in the hypocenter analysis. The uncertainty inherent to an imperfect reference velocity model, modelling, instrumental inaccuracy and phase time picking is propagated into the spacial hypocenter solution. A refined hypocenter methodology is successfully tested in a synthetic experiment with shallow (\(\sim \) 5 km), intermediate (\(\sim \) 10 km) and deep source points (\(\sim \) 15 km). The synthetic experiment indeed shows that it is possible to separate earthquakes by their depth solution, hence offering an indication that the event is either induced or tectonic. Case studies are presented of estimations of hypocenters and error ellipses for (1) induced seismicity at sites for gas storage in salt domes, geothermal production and gas extraction as well as (2) tectonic events.
诱发地震往往发生在浅层,而构造地震往往发生在地球的深层。一个具有不确定性的良好估算的次中心可能有助于评估一个事件是诱发地震还是构造地震。在这项研究中,我们重点开发了一种有助于更好地确定地震源位置并减少测量空间误差的低中心方法。通过同时使用一个台站的 P 波和 S 波相位时差以及成对台站之间的 P 波行进时间差来进行次中心分析,从而获得次中心及其不确定性。不完善的参考速度模型、建模、仪器误差和相位时间选取所固有的不确定性会传播到空间低心解算中。改进后的低心法在一次合成试验中成功地进行了测试,试验中包括浅源点(5千米)、中源点(10千米)和深源点(15千米)。合成实验确实表明,有可能通过深度解来区分地震,从而提供地震事件是诱发地震还是构造地震的指示。本文介绍了对以下两种地震的震源深度和误差椭圆的估算案例:(1) 盐穹储气、地热生产和天然气开采现场的诱发地震;(2) 构造事件。
期刊介绍:
Journal of Seismology is an international journal specialising in all observational and theoretical aspects related to earthquake occurrence.
Research topics may cover: seismotectonics, seismicity, historical seismicity, seismic source physics, strong ground motion studies, seismic hazard or risk, engineering seismology, physics of fault systems, triggered and induced seismicity, mining seismology, volcano seismology, earthquake prediction, structural investigations ranging from local to regional and global studies with a particular focus on passive experiments.