新疆地区一维地壳速度模型研究

利用新疆区域地震台网观测到的2009年1月—2014年7月Pn、Sn、Pg和Sg震相数据,综合使用线性拟合、折合走时、PTD定深方法和HypoSAT定位方法确定该地区Pg、Pb和Pn的平均传播速度(v_(Pg),v_(Pb),v_(Pn))、康拉德界面和莫霍面的深度(H_(conr)和H_(moho))范围,以速度和深度步长分别为0.1km/s、1km精度迭代计算样本数据,通过对比分析计算结果与全国地震统一编目和3400模型下样本数据的定位结果后,确定RMS平均值最小的一维速度模型。在新模型中v_(Pg)、v_(Pb)和v_(Pn)分别为6.10km/s、6.70km/s和8.20km/s,H_(conr)和H_(moho)分别为26km、54km。通过检验对比,认为本文获得的新模型优于新疆地区现有的3400模型。

Study on One Dimensional Crustal Velocity Model of Xinjiang Area

Using the phase data of Pn, Sn, Pg, and Sg recorded by the Xinjiang seismic network from January 2009 to July 2014, the average traveling velocity of the Pg, Pb, and Pn phase (v_pg, v_pb, and v_pn), and the depth range of Conrad and Moho discontinuities (H_conr and H_moho) are determined in the Xinjiang area using linear fitting, reduced travel time, PTD earthquake location, and HypoSAT location methods. Computational iteration is implemented on the sample data with velocity and depth steps of 0.1 km/s and 1 km, respectively. After analyzing and comparing calculated results between sample data from national unified earthquake cataloging and the existing 3400 model for the Xinjiang area, a 1D velocity model with a minimum average RMS is established. The parameters of the new model include v_pg, v_pb, and v_pn of 6.10 km/s, 6.70 km/s, and 8.20 km/s, respectively, and H_conr and H_moho of 26 km and 54 km, respectively. Through tests and comparisons, the new model is found to be superior to the existing 3400 model for the Xinjiang area.