Analysis of the crust displacement in Amazon basin

Abstract

The analysis of the crust displacement in Amazon basin from the comparison between three data sources is the aim of this paper. The data involved are in-situ water level time series measured at ground-based hydrometric station of Agência Nacional de Águas (ANA), vertically-integrated water height deduced from GRACE geoid (height anomaly) and a continuous monitoring GPS station of Instituto Brasileiro de Geografía e Estatística (IBGE). Two analysis are carried out: the first comprehend the GPS vertical coordinate (UP) and in-situ daily data; the second is the 10-day interval of GRACE models, UP and in-situ data for a ~3-years period (January-2006 to December-2008). The GRACE models were computed by Groupe de Recherce de Géodésie Spatiale (CNES/GRGS) and the height anomaly was converted into Equivalent Water Height (EWH). The precise point positing (PPP) is the technique for absolute GPS processing. The Canadian Spatial Reference System (CSRS-PPP) service was used. The coordinate UP presents an annual cycle of vertical displacement with peak-to-peak amplitude of 80-100 mm. A correlation about 90% between in-situ and GRACE is detected. However, they have an inverse phase correlation with the vertical coordinate. This implies that the crust responds instantaneously to the hydrological loading cycle. © Springer-Verlag Berlin Heidelberg 2012.