[G05-3] Positioning applications

[G05-3-02] Crustal deformation in response to the changing climate

^○Shimon Wdowinski¹, Paulo Setti², Tonie van Dam³ (1.Florida International University, 2.Sao Paulo State University, 3.University of Luxembourg)

Vertical crustal movements induced by atmospheric, hydrological, cryospheric, and oceanic load changes are detectable with sub-cm accuracy by precise continuous GPS measurements. Areas subjected to rapid load changes due to icesheet melt, drought, massive groundwater extraction, or lake level drop, are characterized by a dominant non-linear uplift signal. In other areas, seasonal load changes often mask the longer-term climatic signal. Here we present a new method for removing the seasonal signal and extracting the climatic signal from long GPS time series (>15 years). Applying the method to GPS records form western and eastern North America indicates different load change characteristics. In the western US, the seasonal and climatic signals are dominated by hydrological load changes and, consequently, the GPS climatic signal correlates well with the Palmer Severe Drought Index calculated for the same region. In eastern North America the GPS climatic signal in some stations correlates with the North Atlantic Oscillation (NAO) index, suggesting a linkage between decadal scale weather patterns in the Northern Atlantic region and vertical crustal movements, possibly due to ocean and atmospheric load changes. Our results suggest that long continuous GPS observations of vertical crustal movements can serve as independent measures of regional-scale climate change.