{"@context":{"@vocab":"https://cir.nii.ac.jp/schema/1.0/","rdfs":"http://www.w3.org/2000/01/rdf-schema#","dc":"http://purl.org/dc/elements/1.1/","dcterms":"http://purl.org/dc/terms/","foaf":"http://xmlns.com/foaf/0.1/","prism":"http://prismstandard.org/namespaces/basic/2.0/","cinii":"http://ci.nii.ac.jp/ns/1.0/","datacite":"https://schema.datacite.org/meta/kernel-4/","ndl":"http://ndl.go.jp/dcndl/terms/","jpcoar":"https://github.com/JPCOAR/schema/blob/master/2.0/"},"@id":"https://cir.nii.ac.jp/crid/1363670320033170432.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1029/2009jb006584"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2009JB006584"}},{"identifier":{"@type":"URI","@value":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009JB006584"}}],"dc:title":[{"@value":"Discrimination of a preparatory stage leading to <i>M</i>7 characteristic earthquakes off Ibaraki Prefecture, Japan"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:p>An <jats:italic>M</jats:italic>7.0 earthquake struck off Ibaraki Prefecture, Japan, on 8 May 2008. This event was interpreted as belonging to a characteristic earthquake series fracturing the same asperities on the upper boundary of the Pacific plate with a quasi‐regular interval of about 22 years. The previous <jats:italic>M</jats:italic>7.0 occurred in 1982, 26 years before the latest one. I examined the background microseismicity changes preceding these two events by drawing maps of earthquake frequency ratios between two successive periods, and I found a significant similarity between them. This similarity could be expressed numerically by calculating correlation coefficients between the two maps. Surveying the temporal transition of the correlation coefficients, I confirmed that the similarity appeared only for the combination of those maps just before two characteristic earthquakes; it never appeared in the other cases. This result implies the existence and repetition of a typical preparatory stage leading to the characteristic earthquake, which might be caused by a quasi‐static slip on minor asperities in a hierarchical constitution and which forms a specific pattern of seismicity change. This evidence makes it possible to propose a definitive procedure for the practical prediction of the next characteristic earthquake, which is anticipated to occur around 2030. Two kinds of correlation coefficients (r<jats:sub>A</jats:sub> and r<jats:sub>B</jats:sub>) are calculated by treating each seismicity change map just before the 1982 and 2008 events as references. When both r<jats:sub>A</jats:sub> and r<jats:sub>B</jats:sub> exceed the prefixed threshold r<jats:sub>0</jats:sub>, it is possible to announce the time of immediate occurrence of the target earthquake.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1383670320033170432","@type":"Researcher","foaf:name":[{"@value":"Shozo Matsumura"}],"jpcoar:affiliationName":[{"@value":"National Research Institute for Earth Science and Disaster Prevention  Tsukuba Japan"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"01480227"}],"prism:publicationName":[{"@value":"Journal of Geophysical Research: Solid Earth"}],"dc:publisher":[{"@value":"American Geophysical Union (AGU)"}],"prism:publicationDate":"2010-01","prism:volume":"115","prism:number":"B1","prism:startingPage":"1"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2009JB006584"},{"@id":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009JB006584"}],"createdAt":"2010-01-07","modifiedAt":"2023-11-02","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1050013474495795840","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@language":"en","@value":"A review on slow earthquakes in the Japan Trench"}]},{"@id":"https://cir.nii.ac.jp/crid/1360576118691375232","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Sedimentary Structure Derived From Multi‐Mode Ambient Noise Tomography With Dense OBS Network at the Japan Trench"}]},{"@id":"https://cir.nii.ac.jp/crid/1360848658222216064","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Recurring Slow Slip Events and Earthquake Nucleation in the Source Region of the <i>M</i> 7 Ibaraki‐Oki Earthquakes Revealed by Earthquake Swarm and Foreshock Activity"}]},{"@id":"https://cir.nii.ac.jp/crid/1390282679280947584","@type":"Article","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@language":"en","@value":"Reappearance of Characteristic Seismicity Pattern in the Tokai and Tonankai Regions (Seismic Activity Change in the Tokai Region: Part 6)"},{"@value":"東海および東南海地域における特有な地震活動パタンの再現（東海地域の地震活動変化：その6）"}]},{"@id":"https://cir.nii.ac.jp/crid/1390846609814385792","@type":"Article","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@language":"en","@value":"Evaluation of Phenomena Preceding Earthquakes and Earthquake Predictability"}]},{"@id":"https://cir.nii.ac.jp/crid/2051151842042434432","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Streak and hierarchical structures of the Tohoku–Hokkaido subduction zone plate boundary"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1029/2009jb006584"},{"@type":"OPENAIRE","@value":"doi_dedup___::2a290d266df24ac682009a36a95c0f27"},{"@type":"CROSSREF","@value":"10.4294/zisin.63.83_references_DOI_FSXCRKpbJBqhfkbGrbOxw5MAeom"},{"@type":"CROSSREF","@value":"10.1186/s40623-018-0903-8_references_DOI_FSXCRKpbJBqhfkbGrbOxw5MAeom"},{"@type":"CROSSREF","@value":"10.20965/jdr.2020.p0112_references_DOI_FSXCRKpbJBqhfkbGrbOxw5MAeom"},{"@type":"CROSSREF","@value":"10.1029/2021jb021789_references_DOI_FSXCRKpbJBqhfkbGrbOxw5MAeom"},{"@type":"CROSSREF","@value":"10.1029/2018jb015642_references_DOI_FSXCRKpbJBqhfkbGrbOxw5MAeom"},{"@type":"CROSSREF","@value":"10.1186/s40645-022-00528-w_references_DOI_FSXCRKpbJBqhfkbGrbOxw5MAeom"}]}