日本鹿屋台地磁转换函数的变化
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摘要
1996年 10月 19日本九州宫崎发生 7 1级大地震 ,震中离鹿屋地磁台约 90km。分析了鹿屋台 1989～ 2 0 0 1年分钟值资料。周期等于 60min和 4 1min的地磁转换函数Au在 1993年至 1998年初呈现下降趋势。年变率达 0 0 1α- 1。此变化有可能与宫崎地震相关。另外 ,从震前数年Parkinson矢量转向特征推测 ,震源区的电导率似乎是变小的
A strong earthquake of magnitude M S=7 1 occurred on October 19,1996 near the Miyazaki in Kyushu, Japan. The distance between the epicenter and the Kanoya observatory is about 90km. The geomagnetic data sampling in one minute for the Kanoyan observatory are utilized for computing the geomagnetic transfer function in the interval of 1989～2001.The results show that the transfer function A u for the period of 60 and 41 min appears to decrease from 1993 to the beginning of 1998. The annual change rates of these decreasing trend are 0 01 a -1 for the both periods. This feature might be related to the preparation process of the Miyazaki earthquake.Besides, based on rotation feature of the Parkinson arrow in the interval of 1989～2001, the conductivity of the focal zone seems to be decreasing gradually.
A strong earthquake of magnitude M S=7 1 occurred on October 19,1996 near the Miyazaki in Kyushu, Japan. The distance between the epicenter and the Kanoya observatory is about 90km. The geomagnetic data sampling in one minute for the Kanoyan observatory are utilized for computing the geomagnetic transfer function in the interval of 1989～2001.The results show that the transfer function A u for the period of 60 and 41 min appears to decrease from 1993 to the beginning of 1998. The annual change rates of these decreasing trend are 0 01 a -1 for the both periods. This feature might be related to the preparation process of the Miyazaki earthquake.Besides, based on rotation feature of the Parkinson arrow in the interval of 1989～2001, the conductivity of the focal zone seems to be decreasing gradually.
引文
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