青藏高原东北缘宽频带地震台阵远震记录波形及背景噪声分析

本文利用远震极性分析和概率密度函数统计法对国家深部探测专项Sino Probe"青藏高原东北缘宽频带地震台阵"40个台站的远震记录波形和背景噪声进行了评估和影响因素分析。结果表明:(1)该台阵对远震有较好的记录和识别能力,且单台定位结果较好;(2)被检测台站背景噪声达到或接近同类地区固定台站的噪声水平标准,观测数据品质较高;(3)根据实际观测资料计算的各台站概率密度函数PDF分析结果建议,在青藏高原东北缘黄土层较厚地区开展宽频带流动观测,应首选基岩台基以保证三分量观测效果,在不得已选择非基岩台基情况下,应深埋地震计以达到最大程度降噪。

An Analysis of the Tele-seismic Waveforms and Ambient Noise of Temporary Broadband Seismic Array on the Northeastern Margin of the Tibetan Plateau

According to the analysis of tele-seismic waveforms and Probability Density Function (PDF), the ambient noise of the broadband seismic array with 40 stations on the northeastern margin of the Tibetan Plateau was estimated. The results from polarity analysis were also used to test the recording capability of the tele-seismic event. Some conclusions have been reached: (1) the array has good capability for tele-seismic event; (2) the level of background noise of the seismic array is close to that of the permanent stations, the quality of records is high; (3) the results from PDF analysis imply that the best choice of the base for seismometer is the bed rock. The seis-mometer should be buried beneath the ground if there is no bed rock.