{"created":"2021-03-01T06:51:48.265306+00:00","id":33064,"links":{},"metadata":{"_buckets":{"deposit":"a847f3fb-acba-48ed-8a4e-855656b6019e"},"_deposit":{"id":"33064","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"33064"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00033064","sets":["80:4535:4827:4831","9:504:4538:4829:4832"]},"author_link":["128960","128959"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"重力と熱流量データから推定した定常アセノスフェア対流"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1981-03-07","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"3","bibliographicPageEnd":"680","bibliographicPageStart":"653","bibliographicVolumeNumber":"55","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":"Steady-state convection currents of an incompressible Newtonian fluid of very high viscosity in a non-rotating sphericalshell model of the earth's asthenosphere are solved, using the spherical surface harmonic representations of the temperature and fluid velocity fields. The gravity anomaly related to the convection-induced density change is also expressed in a spherical surface harmonic series. The gravity anomaly thus calculated is compared with the gravity data obtained from satellite orbit analyses so as to maximize the mutual correlation coefficient between the two gravity anomalies. As a result, the gravity anomaly calculated with a uniform viscosity of 3.5 × 1O19 N.s.m-2 for an asthenosphere model having a thickness of 300km or 1.5 × 1O20 N.s.m-2 for one having a thickness of 400 km is found to be consistent with the satellite-derived gravity data. It is demonstrated that both gravity anomalies match each other up to some detailed features, for example, the positive anomaly on the Mid-Atlantic Ridge, the negative one widely located in the Mid-Asian continent and the Indian Ocean, etc.","subitem_description_type":"Abstract"},{"subitem_description":"アセノスフェアに熱対流が存在するものと仮定して,グローバルな熱流量分布データから重力場を計算して,これが人工衛星重力とマッチするように,アセノスフェアの深さや粘性を決めようというのが本論文の目的である.まづ球殻を2分し,上部のリソスフェアは熱伝導のみ,下部のアセノスフェアにおいては熱対流によって熱が運ばれるものとし,摂動方程式の解を導く.本来6個の境界条件によって解くのであるが,そのうち,アセノスフェア底面の温度条件のかわりに,リソスフェア表面に観測された熱流量分布を与える.つまり表面で温度勾配を与えることになる.得られた解からブシネスク近似によって密度異常におきかえ,重力を求める.熱流量分布から計算した重力場を人工衛星重力乱れと比較してみると,例えば,厚さ100kmのリソスフェアの下に,厚さ300kmのアセノスフェアがあったとして,粘性3.5×1019N・s・m-2のときに,両者はよい相関を示すことがわかった.細部にわたっても,両者はかなりよい相関を示し,例えば中央大西洋海嶺では,アセノスフェア上部にある小さなローラーセルによって熱流量が高く,かつローラーセルの下部を広く占める冷えたセルの影響によって,正の重力異常が生じることがわかった.これに対して,東太平洋海膨の対流はアセノスフェア底部に達するほどの大きいメガセルをつくっていると考えられる.以上のように,熱流量分布から計算した重力場が,まったく独立に人工衛星軌道から得られた重力場にかなりよく一致するという事実は,採用したモデルの正しさもさることながら,アセノスフェアにおける熱対流機構の存在の可能性を示唆するものではなかろうか.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"128960","nameIdentifierScheme":"WEKO"}],"names":[{"name":"萩原, 幸男"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000033064","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":"Hagiwara, Yukio"}],"nameIdentifiers":[{"nameIdentifier":"128959","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":"ji0553005.pdf","filesize":[{"value":"1.6 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0553005.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/33064/files/ji0553005.pdf"},"version_id":"421d8074-13bb-4e40-8370-80cc1564e76b"}]},"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":"Steady-State Thermal Convection Currents in the Earth's Asthenosphere Inferred from Gravity and Heat Flow Data","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Steady-State Thermal Convection Currents in the Earth's Asthenosphere Inferred from Gravity and Heat Flow Data","subitem_title_language":"en"}]},"item_type_id":"4","owner":"1","path":["4831","4832"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"33064","relation_version_is_last":true,"title":["Steady-State Thermal Convection Currents in the Earth's Asthenosphere Inferred from Gravity and Heat Flow Data"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:08:43.238524+00:00"}