永登系列爆破甘宁青地区地震台网的观测解释与地壳结构

INTERPRETATION TO THE OBSERVATIONAL DATA OF NETWORK OF SEISMIC STATIONS IN GANSU, QINGHAI AND NINGXIA FOR A SERIES OF EXPLOSIONS IN YONGDENG COUNTY AND CRUSTAL STRUCTURE OF THE REGION

摘要:

1982-1983年在甘肃永登地区进行了系列人工大爆破,本文分析研究了甘宁青地震台网的观测记录,求得各种波的平均速度为:V_pg=6.00公里/秒,V_sg=3.56公里/秒,V_pn=8.16公里/秒,V_sn=4.54公里/秒。表层直达纵波速度V_o=4.82公里/秒。莫霍界面上的反射波P_M在140-180公里范围比P_g波强10-7倍。並获得该地区的地壳厚度为:（1）甘肃北山的河西堡-高台一带为48.3公里。古浪-张掖-嘉峪关的河西走廊一带为50.2公里。祁连山南麓为53.6公里。（2）青海中南部为54.4公里。（3）甘肃东部的礼县-武都地压为48.7公里。定西-岷县-通谓地区为50.5公里。（4）宁夏六盘山区为51.6公里。六盘山西侧的甘肃静宁为48.6公里,东侧的平凉为47.5公里,东南端的陕西宝鸡为46.1公里。以上的地壳厚度分布显示了青藏高原地壳在东北边缘的递减,以及甘肃东部地区地壳的某些起伏。

Abstract:

A series of artificial explosions was made from 1982 to 1983 in Yongdeng County, Gansu Province. This paper deals with the data recorded by the stations in Gansu Province, Qinghai Province and Ningxia Hui Autonomous Region. The velocity of every kind of waves is calculated here: V_pg6.00km/sec, V_sg=3.56km/esc, _pn=8.16km/sec, V_sn=4.54kg/sec. The velocity of surface longitudinal wave reaches V_o=4.82km/sec. The reflection wave P_m on Moho discontinuity in 104-180km is 7-10 times greater than P_g wave. The thickness of crust in this region is also gained: 1) Hoxibao-Gaotai, in Gansu, about 48.3km; Gulang-Zhangye-Jiayuguan Pass, 50.2km; the piedmont of Qilianshan Mountain, 53.6km. 2) The middle part and south of Qinghai, 54.4km; 3) Lixian-Wudu, in the east of Gansu, 48.7km. Dingxi-Minxian-Tongwei, 50.5km. 4) Lioupanshan Mountain region, in Ningxia, 51.6km; Jingning, in the west of Lioupanshan Mountain, 48.6 km; Pingliang, in the east of Lioupanshan Mountain, 47.5km; and Baoji, in the southeast of the mountain, 46.1km. It is clear that there is a descend in the edge of northeast of Qinghai-Xizang plateau, by the distribution of crustal thickness mentioned above, but a fluctuation in the eastern area of Gansu Province.