{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T03:01:42Z","timestamp":1760151702697,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,3,31]],"date-time":"2022-03-31T00:00:00Z","timestamp":1648684800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>The Gutenberg\u2013Richter b value describes the ratio between large and small events. A number of studies have suggested that the b value decreases before large earthquakes. In this study, we investigate the temporal variation of the b value of an area along the main rupture zone of the 2008 Wenchuan earthquake (M8.0) prior to the great event. Before estimating b values, we tested the earthquake catalog to make sure that we use the reliable frequency\u2013magnitude distribution by the calculation of MC (completeness of magnitude). We define parameter P (\u0394AIC \u2267 2) values to examine the significance level of b-value changes in the temporal variation by combining a boostrap method with Akaike\u2019s Information Criterion (AIC). The b value in the main rupture zone shows a long-term decrease trend. We then focus on a smaller area where the initial rupture starts. The results show that b values significantly changed about 3 months before the 2008 Wenchuan earthquake in the initial rupture area, indicating that the b value has a potential capability to monitor and detect precursory phenomena of great earthquakes.<\/jats:p>","DOI":"10.3390\/e24040494","type":"journal-article","created":{"date-parts":[[2022,3,31]],"date-time":"2022-03-31T21:33:03Z","timestamp":1648762383000},"page":"494","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Temporal Variation of b Value with Statistical Test in Wenchuan Area, China Prior to the 2008 Wenchuan Earthquake"],"prefix":"10.3390","volume":"24","author":[{"given":"Weiyun","family":"Xie","sequence":"first","affiliation":[{"name":"Graduate School of Science and Engineering, Chiba University, Chiba 263-8522, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6880-406X","authenticated-orcid":false,"given":"Katsumi","family":"Hattori","sequence":"additional","affiliation":[{"name":"Graduate School of Science, Chiba University, Chiba 263-8522, Japan"},{"name":"Center for Environmental Remote Sensing, Chiba University, Chiba 263-8522, Japan"},{"name":"Research Institute of Disaster Medicine, Chiba University, Chiba 263-8522, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9997-8505","authenticated-orcid":false,"given":"Peng","family":"Han","sequence":"additional","affiliation":[{"name":"Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haixia","family":"Shi","sequence":"additional","affiliation":[{"name":"China Earthquake Networks Center, Beijing 100045, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1785\/BSSA0340040185","article-title":"Frequency of earthquakes in California","volume":"34","author":"Gutenberg","year":"1944","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_2","first-page":"12307","article-title":"Earthquake statistics at Parkfield: 1. Stationality of b values","volume":"109","author":"Schorlemmer","year":"2004","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1399","DOI":"10.1002\/2014GL062863","article-title":"On the stress dependence of the earthquake b value","volume":"42","author":"Scholz","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.pepi.2017.04.005","article-title":"Spatio-temporal evolution of frequency-magnitude distribution and seismogenic index during initiation of induced seismicity at Guy-Greenbrier, Arkansas","volume":"267","author":"Mousavi","year":"2017","journal-title":"Phys. Earth Planet. Inter."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.epsl.2019.01.047","article-title":"Axial Seamount: Periodic tidal loading reveals stress dependence of the earthquake size distribution (b value)","volume":"512","author":"Tan","year":"2019","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Xie, W., Hattori, K., Han, P., and Shi, H. (2019). Temporal variation and statistical assessment of b value off the Pacific coast of Tokachi, Hokkaido, Japan. Entropy, 21.","DOI":"10.3390\/e21030249"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1029\/2005GL022679","article-title":"Spatial and temporal b value anomalies preceding the devastating off coast of NW Sumatra earthquake of December 26, 2004","volume":"32","author":"Nuannin","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"20304","DOI":"10.1029\/2012GL052997","article-title":"Decade-scale decrease in b value prior to the M9-class 2011 Tohoku and 2004 Sumatra quakes","volume":"39","author":"Nanjo","year":"2012","journal-title":"Geophys. Res. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1186\/s40623-017-0598-2","article-title":"Anomalous decrease in relatively large shocks and increase in the p and b values preceding the April 16, 2016, M7.3 earthquake in Kumamoto, Japan","volume":"69","author":"Nanjo","year":"2017","journal-title":"Earth Planets Space"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3082","DOI":"10.1038\/s41467-020-16867-5","article-title":"Were changes in stress state responsible for the 2019 Ridgecrest, California, earthquakes?","volume":"11","author":"Nanjo","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Wang, R., Chang, Y., Miao, M., Zeng, Z., Chen, H., Shi, H., Li, D., Liu, L., Su, Y., and Han, P. (2021). Assessing Earthquake Forecast Performance Based on b Value in Yunnan Province, China. Entropy, 23.","DOI":"10.3390\/e23060730"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3473","DOI":"10.5194\/nhess-12-3473-2012","article-title":"Order parameter fluctuations in natural time and b-value variation before large earthquakes","volume":"12","author":"Varotsos","year":"2012","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"9192","DOI":"10.1002\/2014JA020580","article-title":"Study of the temporal correlations in the magnitude time series before major earthquakes in Japan","volume":"119","author":"Varotsos","year":"2014","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"59001","DOI":"10.1209\/0295-5075\/91\/59001","article-title":"Order parameter fluctuations of seismicity in natural time before and after mainshocks","volume":"91","author":"Sarlis","year":"2010","journal-title":"Europhys. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"986","DOI":"10.1073\/pnas.1422893112","article-title":"Spatiotemporal variations of seismicity before major earthquakes in the Japanese area and their relation with the epicentral locations","volume":"112","author":"Sarlis","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1038\/s41586-019-1606-4","article-title":"Real-time discrimination of earthquake foreshocks and aftershocks","volume":"574","author":"Gulia","year":"2019","journal-title":"Nature"},{"key":"ref_17","first-page":"1117","article-title":"Microfractures, aftershocks, and seismicity","volume":"58","author":"Scholz","year":"1968","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/S0012-821X(03)00328-5","article-title":"How do asperities fracture? An experimental study of unbroken asperities","volume":"213","author":"Lei","year":"2003","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"684","DOI":"10.1785\/0120040007","article-title":"Assessing the Quality of Earthquake Catalogues: Estimating the Magnitude of Completeness and Its Uncertainty","volume":"95","author":"Woessner","year":"2005","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1007\/s10712-012-9215-x","article-title":"Investigation of ULF Seismo-Magnetic Phenomena in Kanto, Japan During 2000\u20132010: Case Studies and Statistical Studies","volume":"34","author":"Hattori","year":"2013","journal-title":"Surv. Geophys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4998","DOI":"10.1002\/2014JA019789","article-title":"Statistical analysis of ULF seismo-magnetic phenomena at Kakioka, Japan, during 2001\u20132010","volume":"119","author":"Han","year":"2014","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1093\/gji\/ggw404","article-title":"Evaluation of ULF seismo-magnetic phenomena in Kakioka, Japan by using Molchan\u2019s error diagram","volume":"208","author":"Han","year":"2017","journal-title":"Geophys. J. Int."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"485","DOI":"10.3319\/TAO.2018.03.11.01","article-title":"Statistical analyses on the ionospheric total electron content related to M \u2265 6.0 earthquakes in China during 1998\u20132015","volume":"29","author":"Liu","year":"2018","journal-title":"Terr. Atmos. Ocean. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Ouzounov, D., Pulinets, S., Hattori, K., and Taylor, P. (2018). Statistical Analysis and Assessment of Ultralow Frequency Magnetic Signals in Japan As Potential Earthquake Precursors. Pre-Earthquake Processes: A Multidisciplinary Approach to Earthquake Prediction Studies, Wiley.","DOI":"10.1002\/9781119156949"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Ouzounov, D., Pulinets, S., Hattori, K., and Taylor, P. (2018). Multiparameter Assessment of Pre-Earthquake Atmospheric Signals. Pre-Earthquake Processes: A Multidisciplinary Approach to Earthquake Prediction Studies, Wiley.","DOI":"10.1002\/9781119156949"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Han, P., Zhuang, J., Hattori, K., Chen, C.H., Febriani, F., Chen, H., Yoshino, C., and Yoshida, S. (2020). Assessing the potential earthquake precursory information in ULF magnetic data recorded in Kanto, Japan during 2000\u20132010: Distance and magnitude dependences. Entropy, 22.","DOI":"10.3390\/e22080859"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e2020JB020108","DOI":"10.1029\/2020JB020108","article-title":"Statistical correlation analysis between thermal infrared anomalies 1 observed from MTSATs and large earthquakes occurred in Japan (2005\u20132015)","volume":"126","author":"Genzano","year":"2021","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Yu, Z., Hattori, K., Zhu, K., Fan, M., and He, X. (2021). Evaluation of pre-earthquake anomalies of borehole strain network by using Receiver Operating Characteristic Curve. Remote Sens., 13.","DOI":"10.3390\/rs13030515"},{"key":"ref_29","first-page":"139","article-title":"On seismicity, in report of the Joint Research Institute for Statistical Mathematics","volume":"34","author":"Utsu","year":"1992","journal-title":"Inst. Stat. Math. Tokyo"},{"key":"ref_30","first-page":"12308","article-title":"Earthquake statistics at Parkfield: 2. Probabilistic forecasting and testing","volume":"109","author":"Schorlemmer","year":"2004","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_31","first-page":"3308","article-title":"Rupture triggering process of Wenchuan earthquake seismogenic faults","volume":"57","author":"He","year":"2014","journal-title":"Chin. J. Geophys.Chin. Ed."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"859","DOI":"10.1785\/0119990114","article-title":"Minimum magnitude of complete reporting in earthquake catalogs: Examples from Alaska, the WesternUnited States, and Japan","volume":"90","author":"Wiemer","year":"2000","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_33","first-page":"237","article-title":"Maximum likelihood estimate of b in the formula log N= a-bM and its confidence limits","volume":"43","author":"Aki","year":"1965","journal-title":"Bull. Earthq. Res. Inst."},{"key":"ref_34","first-page":"99","article-title":"A method for determining the value of b in a formula log n=a-bM showing themagnitude-frequency relation for earthquakes","volume":"13","author":"Utsu","year":"1965","journal-title":"Geophys. Bull. Hokkaido Univ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1007\/s10950-016-9589-1","article-title":"Gutenberg-Richter b-value maximum likelihood estimation and sample size","volume":"21","author":"Nava","year":"2017","journal-title":"J. Seismol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"568","DOI":"10.1007\/BF02893477","article-title":"Development of China Digital Seismological Observational Systems","volume":"16","author":"Liu","year":"2003","journal-title":"Acta Seismol. Sin."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1677","DOI":"10.1785\/BSSA0720051677","article-title":"The standard error of the magnitude-frequency b value","volume":"72","author":"Shi","year":"1982","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1126\/science.1216142","article-title":"Critical Truths About Power Laws","volume":"335","author":"Stumpf","year":"2012","journal-title":"Science"}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/24\/4\/494\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:47:53Z","timestamp":1760136473000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/24\/4\/494"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,31]]},"references-count":38,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2022,4]]}},"alternative-id":["e24040494"],"URL":"https:\/\/doi.org\/10.3390\/e24040494","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2022,3,31]]}}}