{"created":"2021-03-01T06:51:42.256671+00:00","id":32973,"links":{},"metadata":{"_buckets":{"deposit":"803b8d96-e416-4a1b-a76d-d417bc49729b"},"_deposit":{"id":"32973","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"32973"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00032973","sets":["80:4535:4807:4808","9:504:4538:4809:4810"]},"author_link":["128562","128561"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"表面波の初期位相と位相速度の精度 : 特に一観測点法に関連して"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1983-03-31","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"4","bibliographicPageEnd":"652","bibliographicPageStart":"627","bibliographicVolumeNumber":"57","bibliographic_titles":[{"bibliographic_title":"東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo"}]}]},"item_4_description_13":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_4_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Initial phase of surface waves, which depends on such earthquake source parameters as depth, source-type and -orientation, source time function and medium property near the source, is investigated specially with respect to accuracy. The effects of small errors in the solution of the earthquake mechanism and uncertainties of the local underground structure near the source region on the initial phase of surface waves are quantitatively examined on the basis of the dislocation theory. By assuming the errors of source parameters and by using different medium models, the errors of the initial phase and surface wave velocity are evaluated. Against an error of ±5° in the dip and slip angles of the fault plane at the source, the space phase error in the initial phase is negligible in most parts of the azimuth except the minimum amplitude direction. Against an error of the source time function, the phase error of 0.1 radian or so may be caused at the period 40 sec and it decreases as the period increases. If we assume an earthquake with the magnitude 6 to be a point source, a phase error of maximum 0.4 radian in the initial phase due to the finite fault length will be produced at the azimuth just opposite to the rupture direction. It can be said that the space phase error due to uncertainties of the medium property near the source is negligible as far as we use a reasonable model representing the source region. Among the three phase factors of the initial phase, the error of the rupture propagation phase is largest, and the initial phase error decreases as the period increases. The total error of the initial phase seems not to exceed 0.6 radian at the period 40 sec and 0.3 radian at 100 sec, when an earthquake with the magnitude 6 or less is used and the station is carefully chosen in order to select the azimuth of the stable portion of the initial phase, by taking the amplitude radiation pattern of surface waves at the source into consideration. For an error in the  initial phase of 0.6 radian at the periods 40 and 100 sec, for the path length of about 9000 km, the phase velocity error of Rayleigh waves is estimated to be 0.007 km/sec (0.17%) and 0.018 km/sec (0.44%) respectively.","subitem_description_type":"Abstract"},{"subitem_description":"震源の深さ,型,方向性,震源時間関数,震源近傍の媒質の属性等,地震の震源パラメ－タに依存する表面波の初期位相が特に精度に関連して研究されている.地震メカニズム解の小さな誤差や震源近傍の局地的な地下構造の不確定さが表面波の初期位相に及ぼす効果が転位理論に基いて定量的に調べられている.震源パラメータの誤差を仮定し,異なる媒質モデルを使う事により,初期位相と表面波速度の誤差が計算されている.震源に於ける断層面の傾斜角と滑り角の±5°の誤差に対して初期位相の空間位相の誤差は,最小振幅方向を除けば,多くの所で無視し得る.震源時間関数の誤差に対しては,0.1ラジアン前後の位相角誤差が周期40秒で生じ,かつその誤差は周期と共に減少する.もしマグニチュード6の地震を点震源と見做すと,有限な断層の長さによる初期位相の誤差,最大で0.4ラジアンの誤差が破壊伝播方向と丁度反対の方位角度で生じるであろう.震源近傍の媒質の属性の不確定さによる空間位相誤差は,震源域を代表する適当なモデルを使う限りに於て無視し得るといえる.初期位相の三つの位相因子の中では,破壊伝播位相の誤差が空間位相や時間位相の誤差よりも大であり,初期位相の誤差は周期の増加と共に減少する.マグニチュード6前後の地震が使われ,震源に於ける表面波の振幅ラジエーションパターンが考慮され,かつ観測点が初期位相の安定した所になるような方位であるように注意深く選択されれば,初期位相の総合的な誤差は周期40秒で0.6ラジアン,周期100秒で0.3ラジアンを越えないであろうと思われる.周期40秒と100秒で初期位相の誤差±0.6ラジアンに対して,径路の長さが約9000kmの場合には,レイリー波の位相速度の誤差はそれぞれ■0.007km/sec(0.17%)と■0.018km/sec(0.44%)に見積られる.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"128562","nameIdentifierScheme":"WEKO"}],"names":[{"name":"吉田, 満"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000032973","subitem_identifier_reg_type":"JaLC"}]},"item_4_publisher_20":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"東京大学地震研究所"}]},"item_4_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00162258","subitem_source_identifier_type":"NCID"}]},"item_4_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"00408972","subitem_source_identifier_type":"ISSN"}]},"item_4_subject_15":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"453","subitem_subject_scheme":"NDC"}]},"item_4_text_21":{"attribute_name":"出版者別名","attribute_value_mlt":[{"subitem_text_value":"Earthquake Research Institute, University of Tokyo"}]},"item_4_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"地震研究所"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Yoshida, Mitsuru"}],"nameIdentifiers":[{"nameIdentifier":"128561","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-06-26"}],"displaytype":"detail","filename":"ji0574002.pdf","filesize":[{"value":"1.5 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0574002.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/32973/files/ji0574002.pdf"},"version_id":"e779fd82-500a-4b2f-bbc2-719eb62ffc8a"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"Accuracy of the Initial Phase and the Phase Velocity of Surface Waves with Special Reference to the Single-Station Method","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Accuracy of the Initial Phase and the Phase Velocity of Surface Waves with Special Reference to the Single-Station Method","subitem_title_language":"en"}]},"item_type_id":"4","owner":"1","path":["4808","4810"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"32973","relation_version_is_last":true,"title":["Accuracy of the Initial Phase and the Phase Velocity of Surface Waves with Special Reference to the Single-Station Method"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:08:27.785400+00:00"}