1986年冬季中国南极长城站的地震观测

1986年3月30日至12月25日为期271天的冬季地震观测中,中国南极长城站地震台共记录到各种震动3000余次,其中大部分为长城湾冰层破裂产生的微震,4次为南设得兰群岛邻近海域中的浅源地震以及5月7日阿留申群岛发生的8.1级地震和4月14日南桑韦奇群岛发生的6.4级地震。冰震与构造地震具有明显的差异。1986年11月16日的地震记录为分析冰震与构造地震的区别提供了很好的例证。冰震具有初动尖锐、频率高和衰减快的特征。根据初动和波型很容易将冰震与构造地震区分开。

SEISMOLOGICAL OBSERVATION AT THE GREAT WALL STATION DURING AUSTRAL WINTER OF 1986

The seismological observation has been made on seismographs at the Great Wall Station during the period of 271 days from March 30 to October 25, 1986. Total more than 3000 seismic events were recorded,most of them are microseisms generated by breaking and fracture of ice layers, 4 are the shallow earthquakes in sea area near South Shetland Islands, a M=8.1 earthquake occurred at Aleutan Islands on May 7.1986, and a M=6.4 earthquake occurred at South Sandwish Islands on April 14, 1986. There is a significant difference between icequake and tectonic earthquake. The seismic records on Nov. 16, 1986, provide an excellent case for distinguishing icequake from tectonic earthquake. The icequake is characterized by a sharp first motion, high frequency and rapid attenuation. So it is easy to distinguish the icequake from the tectonic earthquake by their first motions and waveforms.