乌鲁木齐市东北郊碗窑沟断层超浅层地震探测初步研究

Elementary Research on Ultra-Shallow Seismic Exploration on Wanyaogou Fault in Northeastern Suburb of Urumqi

摘要:

碗窑沟断层是乌鲁木齐市主要的晚更新世中期活动断层,在市区与郊区被厚约数十米的第四系所覆盖。本文介绍了在乌鲁木齐市东北郊干扰背景较小地段对碗窑沟断层进行的超浅层纵波反射探测情况。在选取小道间距、适当偏移距、短排列、多次覆盖、高频检波器接收的工作方法和合理数据处理方法基础上,获取了3条典型纵波反射剖面,都可较清楚地分辨出第四系底界和断层位置。表明在探测环境比较好的条件下,采用合适的观测系统,在断层两盘介质存在明显差异的地区可以采用纵波反射方法探测出埋深小于50 m的断层。

Abstract:

Wanyaogou Fault is the main active fault in Urumqi city, Xinjing Uygur Autonomous Region, which had avtived in the middle period of late-Pleistocene. It is covered by the Quaternary deposits with depth of some tens meters in urban and suburban areas of Urumqi. In this paper, ultra-shallow P-wave reflection exploration for Wanyaogou Fault in northeastern suburb of Urumqi with less interference background is introduced. In the exploration, we used the methods of small geophone group interval, proper offset, short spread, multiple stacking fold and high-frequency geophones, as well as appropriate data processing method, 3 typical P-wave reflection profiles are carried out, from which the Quaternary base interface and the locations of the faults can be distinguished. The results show that in the good exploration environment, only if the proper surveillance layout is selected and the difference between the medium of both side is distinct, the uhra-shallow P-wave reflection method can be applied to detect the fault with depth of less than 50 m.