日本鹿屋台地磁静日变化中可能存在的震磁效应
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摘要
1996年 10月 19日日本九州宫崎 (Miyazaki)发生 7 1级地震 ,震中距鹿屋地磁台约 90km。利用Sq单台Z/H法分析了 1981～ 1998年鹿屋台与佘山台的资料 ,再研究两台视深比随时间的变化 ,结果表明 ,地震前一年多时间内视深比出现较大的负异常 ,同期的佘山与武汉台的视深比曲线未出现类似的异常现象。因此 ,上述异常可能与宫崎地震有关
This is the second report on the topic whether seismomagnetic signals exist in the Sq variations of three magnetic components before great earthquakes. A great earthquake of M S7 1 occurred on October 19, 1996 near the Kanoya magnetic observatory in Miyazaki, Kyushu, Japan. The distance between the epicenter and the Kanoya observatory is about 90 km. The author analyses the apparent depths of the Kanoya and Sheshan observatories for the period of 24 h using the single station Z/H method ,and investigates the time changes of apparent depth ratio between the two observatories. The results shown in this paper indicate that a negative anomalous change in the time variations of apparent depth ratio appeared within one year interval before the earthquake occurrence.Furthermore , the time changes of apparent depth ratio between the Sheshan and Wuhan for the same interval did not appear significant anomalous change.Therefore, the anomalous change stated above might be related to the Miyazaki earthquake.
This is the second report on the topic whether seismomagnetic signals exist in the Sq variations of three magnetic components before great earthquakes. A great earthquake of M S7 1 occurred on October 19, 1996 near the Kanoya magnetic observatory in Miyazaki, Kyushu, Japan. The distance between the epicenter and the Kanoya observatory is about 90 km. The author analyses the apparent depths of the Kanoya and Sheshan observatories for the period of 24 h using the single station Z/H method ,and investigates the time changes of apparent depth ratio between the two observatories. The results shown in this paper indicate that a negative anomalous change in the time variations of apparent depth ratio appeared within one year interval before the earthquake occurrence.Furthermore , the time changes of apparent depth ratio between the Sheshan and Wuhan for the same interval did not appear significant anomalous change.Therefore, the anomalous change stated above might be related to the Miyazaki earthquake.
引文
[1] 陈伯舫 .用地磁静日变化研究深部电导率的单台Z/H法 [J].地球物理学报 ,1992 ,35 (增刊 ) :40 1- 40 7.
[2 ] 陈伯舫 .地磁日变化中的震磁效应研究 [J].地震学报 ,1994,16 (3) :36 1- 36 7.
[3] ChapmanS ,BartelsJ.Geomagnetism [M].Oxford :ClarendonPress ,1940 . 10 49.
[4 ] HonkuraY ,MatsushimaM .Electromagneticresponseofthemantletolong -periodgeomagneticvariationsovertheglobe [J].EarthPlanetsSpace ,1998,5 0 (8) :6 5 1- 6 6 2 .
[5 ] ParkinsonWD ,HuttonVRS .TheelectricalconductivityoftheEarth [A].In :JacobsJA (editor) .Geomagnetism [C].London :AcademicPress,1989.2 6 1- 32 1.
[6 ] SchmuckerU .Anintroductiontoinductionanomalies [J].J.Geomag .Geoelectr.,1970 ,2 2 (1) :9- 33.
[2 ] 陈伯舫 .地磁日变化中的震磁效应研究 [J].地震学报 ,1994,16 (3) :36 1- 36 7.
[3] ChapmanS ,BartelsJ.Geomagnetism [M].Oxford :ClarendonPress ,1940 . 10 49.
[4 ] HonkuraY ,MatsushimaM .Electromagneticresponseofthemantletolong -periodgeomagneticvariationsovertheglobe [J].EarthPlanetsSpace ,1998,5 0 (8) :6 5 1- 6 6 2 .
[5 ] ParkinsonWD ,HuttonVRS .TheelectricalconductivityoftheEarth [A].In :JacobsJA (editor) .Geomagnetism [C].London :AcademicPress,1989.2 6 1- 32 1.
[6 ] SchmuckerU .Anintroductiontoinductionanomalies [J].J.Geomag .Geoelectr.,1970 ,2 2 (1) :9- 33.
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