Comparison and Analysis of Crustal Vertical Deformation in Mainland China Observed by GPS from CMONOC and GRACE

JIA Lulu, WANG Yuebing, LIAN Weiping, XIANG Longwei
2018 Acta Geodaetica et Cartographica Sinica  
Based on continuous GPS data from crustal movement observation network of China (CMONOC), the vertical deformations on Earth's surface observed by 234 GPS stations and GRACE in mainland China are compared with each other.GPS-observed and GRACE-derived vertical deformations are in good agreements in general, which indicates that mass loading is an important factor to GPS nonlinear variations, but there are some differences between GPS and GRACE.For further analyzing the difference between GPS
more » ... GRACE vertical deformations, we take into account the thermal expansion effects to GPS vertical deformations and the effect of regional crustal structure on vertical loading deformations derived from GRACE.It is found that the annual amplitudes of vertical deformations induced by thermal expansion are not less than 1 mm at more than 50% of GPS stations.After considering thermal deformations, the vertical deformations of GPS and GRACE are with higher consistency in mainland China.The ratio of annual amplitudes from GPS and GRACE vertical deformations changes from 1.07±0.06 to 1.01±0.05, which is closer to the ideal value of 1.Thermal expansion can explain 6.2% of the difference between GPS and GRACE vertical deformations.And it can increase the consistency of vertical deformations between GPS and GRACE by 11.2% relatively after thermal expansion correction.The regional crustal structure has little effect on GRARE-derived vertical loading deformations in mainland China and the relative difference is 2.5%.
doi:10.11947/j.agcs.2018.20170281 doaj:238d8ba94e6b4c8b90f107469e88f9bf fatcat:kbikl7aiijbu3jy6jqnwozip3i