顾及有色噪声影响的青海地区应变场分析

Analysis of strain field considering the influence of colored noise in Qinghai area

基于青海地区14个中国大陆构造环境监测网络(CMONOC)连续站10年的坐标时间序列数据,利用贝叶斯信息准则(BIC)确定各连续站的最优噪声模型,进而得出修正后的水平速度场,并在此基础上建立整体旋转与线性应变模型来分析青海地区的应变特征.结果表明:青海地区CMONOC连续站坐标时间序列各方向的噪声特性存在较大差异,东(E)、北(N)、天顶(U)方向的最优噪声模型分别为白噪声+幂律噪声(WN+PL)、白噪声+高斯-马尔科夫噪声(WN+GGM)和白噪声+闪烁噪声(WN+FN).考虑有色噪声(CN)影响青海地区CMONOC连续站基于ITRF2014框架下的平均水平运动速率为39.45 mm/a,运动方向为88°57′58″NEE.青海地区构造活动相对强烈的东北与西南部分别表现为挤压应变特征和拉张应变特征;从东北向西南,挤压应变逐渐减小,拉张应变逐渐增大,总体表现为挤压应变.

Based on the 10-years coordinate time series data of crustal movement observation network of 14 china(CMONOC)continuous stations in Qinghai,the optimal noise model of each continuous station was determined by using Bayesian information criterion(BIC),and then the modified horizontal velocity field was obtained.On this basis,the global rotation and linear strain model was established to analyze the strain characteristics in Qinghai.The results show that the noise characteristics of CMONOC continuous station in Qinghai are different in different directions.The optimal noise models in east(E),north(N)and up(U)directions are“white noise+power law noise(WN+PL)”,“white noise+Gaussian Markov noise(WN+GGM)”and“white noise+flicker noise(WN+FN)”respectively.After considering the influence of colored noise(CN),the average horizontal motion velocity of CMONOC continuous station in Qinghai based on the framework of ITRF2014 is 39.61 mm/a and the motion direction is 88°57'58"NEE.The northeastern and southwestern parts of the Qinghai region with relatively strong tectonic activities are characterized by compressive strain and tensile strain,respectively.From northeast to southwest,the compression strain gradually decreases and the tensile strain gradually increases,which is generally manifested as the compression strain.