新疆乌什6.4级地震的热异常

THERMAL ANOMALIES OF THE M6.4 WUSHI, XINJIANG, EARTHQUAKE

本文分析了乌什6·4级地震200公里左右范围内的气温、地温、冻土深度等资料,结果表明,震前这些气象要素有较普遍的短临异常显示。短期异常出现的优势时间在震前50—20天,临震异常出现在震前7天之内;异常主要分布在震中附近200公里以内,近处异常大于远处,异常似乎有沿构造带及其端都显示更明显的特点。相距90公里的阿合奇为本次地震热异常盲区,超过300公里无明显异常;深层地温异常范围较浅层大,出现异常的时间较早,持续时间也较长;临震异常幅度大而持续时间短,具有动态特性;气温的临震异常有由震中向外传播的特点,传播速度45公里/小时,幅度则随震中距衰减,衰减方程具有t=a(1/Δ(3/2))+b/Δ的形式。

In this paper, the data concerning temperature, geotemperature, and tjael depth within a range of about 200 km of the M6.4 Wushi earthquake have been analysed. The obtained result indicates that there generally existed short-aud-immediate-term anomalies of those meteorological facors, with a dominant time of 50-20 days before the event for short-term anomalies and 7 days for immediate-term ones. Those anomalies were mainly distributed within a range of about 200 km, with a character of the closer to the epicenter the more conspicuous the anomalies that seemed to be more striking along the structural belt and on its both ends. Aheqi with an epicentral distance of 90 km was the blind-zone of thermal anomalies of the event and no obvious anomalies could be found over 300 km. The geotemperature anomalies in deep layer appeared a larger range, an earlier time and a longer duration than that in shallow layer. The immediate-term anomalies appeared a large amplitude and a short duration, with dynamic features. The immediate temperature anomalies featured a transference from epicenter to the out side, with a velocity of 45 km/h and an amplitude attenuated with epicentral distance [ The attenuationequation is in the form of t = a (1/(Δ2/3)) +6/Δ].