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

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.