{"created":"2021-03-01T06:51:33.569782+00:00","id":32842,"links":{},"metadata":{"_buckets":{"deposit":"a63db535-050d-4004-9852-7fa1416e0f49"},"_deposit":{"id":"32842","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"32842"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00032842","sets":["80:4535:4757:4758","9:504:4538:4759:4760"]},"author_link":["77310","77311","77308","77309"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Aerial Path Determination of a Great Fireball from Sonic Boom Records on Seismographs"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1988-03-31","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"4","bibliographicPageEnd":"588","bibliographicPageStart":"579","bibliographicVolumeNumber":"62","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_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"1987年9月11日に西日本上空に出現した大火球は,進行中に強い衝撃波を発生させた.その衝撃波が地表に達したときの震動は,東京大学地震研究所,白木微小地震観測所の6ケ所の地震計,高知大学地震観測点の2ケ所の地震計に記録された.これらの地震記録から計算した結果,火球は,東経133°,北緯34°.28の地点を68.6kmの高さで通過し,北から37°.7西に向いた方向へ,水平と34°.3の角をなして通過したことがわかった.したがってこの火球は四国を越えて広島県北部に達したと見られる.地震計の記録だけから火球径路が決定できたのはこれが初めてのことである.これだけはっきりと径路を決めることができれば,隕石捜索の場合には非常に有力な資料となる.","subitem_description_type":"Abstract"},{"subitem_description":"On the night of September 11, 1987, a great fireball appeared over Western Japan. Although it was cloudy, the fireball was witnessed by many people between or through the clouds. After a few minutes, Hiroshima Prefecture and its environs were hit by a large detonation like a thunderbolt. In its central area, some earth tremors were felt. They were believed to have been generated by a sonic boom from the fireball. One of the authors soon found that the ground tremor was recorded on a seismograph at the Mikawa Station, Shiraki Micro-Earthquake Observatory, Earthquake Research Institute. Then, by detailed investigation, sonic boom records were also found at five stations of the Observatory and two stations of Kochi University. In all, precise arrival times of the shock front were obtained at eight stations. Since the propagation of the shock wave is well known, we can determine the fireball path from the arrival times. The calculation was carried out assuming the fireball velocity to be constant and the mean speed of sound to be 312 m・s-1. These simplifications are reasonable when the sonic boom is strong. The fireball path was as given below. At the instant when the fireball passed through the meridian of 133°E, Position {Latitude : 34°.28±0°.03 Height : 68.6 km±2.2 km Forward {Azimuth : 37°.7±0°.9 (from north to west) direction Declination : 34°.3±0°.7 Passage time : 13h8m50s±3s (UT) This was the first case that an aerial path of a fireball was precisely determined from seismograph records only. This will give a powerful clue for searching for meteorites.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"77310","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Nagasawa, Ko"}]},{"nameIdentifiers":[{"nameIdentifier":"77311","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Miura, Katsumi"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000032842","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":"長沢, 工"}],"nameIdentifiers":[{"nameIdentifier":"77308","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"三浦, 勝美"}],"nameIdentifiers":[{"nameIdentifier":"77309","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":"2017-06-13"}],"displaytype":"detail","filename":"ji0624012.pdf","filesize":[{"value":"554.8 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0624012.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/32842/files/ji0624012.pdf"},"version_id":"397f59da-8ea9-4fdc-a847-c513f630a947"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"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":"地震計記録から決定した1987年9月11日の大火球の径路","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"地震計記録から決定した1987年9月11日の大火球の径路","subitem_title_language":"ja"}]},"item_type_id":"4","owner":"1","path":["4758","4760"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2016-12-28"},"publish_date":"2016-12-28","publish_status":"0","recid":"32842","relation_version_is_last":true,"title":["地震計記録から決定した1987年9月11日の大火球の径路"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T05:17:30.427373+00:00"}