Analysis Of Non-tectonic Crustal Deformation In Shandong Region

In recent years,the technology of GPS develop quickly,and the application become wider and wider,but the precision of GPS needs to be improved in vertical direction,which is only 5~10mm.By the study,in vertical direction Non-Tectonic crustal deformation even reaches the magnitude of CM.When studying the deformation related to earthquake or crustal movement,the influence of nontectonic deformation cannot be ignored.So it is a significant issue how to effectively identify,screen and remove a series of nontectonic deformation interference in the GPS time series,as to better serve detections and analysis of earthquake risks,and is also an important subject of GNSS geodetic survey.This paper mainly studies the deformation of OTL l and the deformation of land water load in Non-Tectonic Crustal Deformation deformation.Ocean tide loading(OTL)cannot be ignored in GPS date processing.Shandong is located in coastal areas,and the ocean tide models have large differences in shallow water area,so this article take the date of SDCORS as an example,with GAMIT,to show the effect of ocean tide loading on GPS measurement in Shandong region,based on four ocean tide models(FES2004?NAO99b?CSR4.0?GOT00.2).The effect of OTL on GPS positioning is mainly reflected on the U direction,the amplitude of effect is centimeter level;The effect of coastal area is 2 times as large as that of inland regions;The effect of OTL on baselines solution have relation to baseline azimuth and the OTL difference between the two stations,the largest of amplitude on the U direction is nearly 8 mm.The effects of OTL computed from different ocean tide model for Shandong region in long time observation are not significant,but in short time or real-time observation,the phase accuracy of Semidiurnal constituent need enhancement,so it's indispensable to refine a Shandong region ocean tide model.The terrestrial water storing changes(TWSC)in Shandong region was inferred using the GRACE monthly gravity date from 2006 to 2014.And using the precipitation data of Shandong meteorological station,we analyze the correlation between TWS and precipitation date.As the result,the spatial distribution of TWSC shows a downward trend in the most part of Shandong region during this period of time.The declining rate trend to be gentle from west to east,with the maximum rate of-17.9±1.26mm/a appearing in the southwest of Shandong region;The correlation between TWSC and precipitation is not obvious from the monthly variation;But TWSC and precipitation show strong correlation(0.673)from annual variation,TWSC shows a downward trend which is about-5.75±0.29mm/a in overall Shandong region,so precipitation is the main factor,which affecting TWSC in Shandong region.The annual amplitude of land water reserves in shandong province is between-0.2 and 0.4mm,and the annual amplitude of land water load is obviously negative correlation with the change rate of land water reserves.