中国西部地震的记录特征及震级测定

The recording feature and determination of magnitude of earthquakes in western China

从温州台大震速报的角度叙述了我国西部地区浅源地震的记录特征及震源参数测定 ,并对云南地震的震级异常进行了讨论。西部地震的记录特征为 :震相简单 ,P波微弱 ,LQ在 NS向早到 ;青海地震 S波三分向均强 ;云南地震 NS向 LQ波表现为一个周期的强脉冲形 ;四川地震 NS向 LQ 显得突出 ,且持续时间较长。对于云南地震 ,温州台所测定的震级明显偏高 ,需加震源校正。

The recording feature and the hypocenter parameter determination of the shallow focus earthquakes in western China are described from the aspect of the quick report of strong earthquakes,then discusses the magnitude abnormality of Yunnan earthquake.The main recording feature of these earthquakes is concluded as:simple phases,weak P wave,L Q wave arrives earlier than normal at NS(component).For earthquakes in Qinghai,S wave is strong at three(components).And for Yunnan earthquakes,L Q wave appears as a strong pulse of a single period.For Sichuan earthquakes,L Q at NS(components)is very significant and lasts longer.For Yunnan earthquake,the magnitude determined by Wenzhou Station is remarkably higher,so a source correction is necessary.