Study Of Crustal Movement In Fen-wei Rift Zone Based On GAMIT/GLOBK And QOCA

Fen-Wei rift zone region located in several intersecting tectonic plates, its geographicallocation and complex tectonic setting and laying the root cause of frequent neotectonism andgeological hazards. Country has great importance to the Earth’s crust monitoring of this rift. Inthis paper, Fen-Wei rift zone and its adjacent region is considered as the research object,choose the data of2011-2013years from land State network project of36continuous GPSstations and277mobile observation stations, useing high precision GPS data processingsoftware GAMIT/GLBOK and GPS data post-processing software QOCA finish the followingstudies:Firstly, GAMIT/GLBOK software is used to process the data of36GPS continuousstation and227mobile observing regional station from land-based state network engineering,obtain the high-precision coordinate and the time series in the region GPS site under theITRF2008framework.Secondly, GPS data post-processing software QOCA is used to remove the continuousstations displacement in a series of recurring elements, and common-mode error, and othernon-construction deformation. The speed accuracy of GPS crustal monitoring stations forhorizontal movement was improved about0.3mm, and the speed accuracy of the verticalmovement was improved about0.6mm. By continuous GPS station QOCA softwareprocessing parameter information, constructing Delaunay Triangulation, combined with theinverse distance interpolation algorithm for GPS mobile observation stations ofnon-construction noise elimination, the GPS regional site mobile monitoring, horizontalmovement speed accuracy was improved about0.6mm, and the vertical movement speedaccuracy was improved about1.7mm.Thirdly, by calculating the Euler parameter of the Eurasian plate, gets the Fen-Wei riftzone with continuous and regional stations relative to the Eurasian plate clean horizontalmovement speed, according to the horizontal velocity image we can know: the Fen-Wei rift relative to the Eurasian plate has a trend of moving in a south-easterly direction, and has aslight clockwise rotation, the overall average movement speed is6.3mm/yr. Near area ofOrdos block body movement speed is small, in Qinghai-Tibet plateau northeast edge areamovement speed is obviously larger, after calculation average can reached8mm/yr; in Weiheto Graben within Central speed direction appeared chaos, occasionally has East partial Northof speed, from geology angle analysis, may due to this regional fault section actingdevelopment more; in fenhe to Graben overall speed East partial South trend reduces, overallspeed than Ordos block body speed big. Reflecting differences of fen-Wei rift with internalcampaign demonstrated the Fen-Wei active than its neighbouring crustal movement of thecrust, also indirectly shows recent earthquake-prone part of the reason in this research area.Finally, the GPS vertical data is used to analyze: The overall trend of vertical motion ofFen-Wei rift zone and the adjacent areas is less obvious under the ITRF2008the framework,movement in Weihe basin is small and relatively stable, the Fenhe River basin has a big riseand fall, generally dominated by rise. Meanwhile obtain the conclusion that relative to theOrdos plate (continuous SNYA station) the vertical motion to sink. Compare with a largenumber of level measurement data of fen-Wei rift zone and its adjacent areas showed: thewhole movement of GPS monitoring and level measurement monitoring is essentially similar,especially continuous GPS station vertical motion trends show more clearly.It indicates thatGPS overall monitoring of vertical motion has a certain reliability in the Fen-Wei rift zoneand its adjacent areas.