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TitleAnalysis of GPS measurements in eastern Canada using principal component analysis
AuthorTiampo, K F; Mazzotti, S; James, T S
SourcePure and Applied Geophysics 2011 p. 1-24,
Alt SeriesEarth Sciences Sector, Contribution Series 20110184
Mediaon-line; digital
File formatpdf
ProvinceNew Brunswick; Nova Scotia; Quebec; Ontario; Eastern offshore region
NTS11D; 11E; 11F; 11K; 11L; 12E; 12F; 12K; 12L; 12M; 12N; 21; 22; 30M; 31; 32; 40I; 40J; 40O; 40P; 41A; 41B; 41G; 41H; 41I; 41J; 41O; 41P; 42A; 42B; 42G; 42H; 42I; 42J; 42O; 42P
AreaQuebec City; Montreal; Ottawa
Lat/Long WENS -84.0000 -60.0000 52.0000 40.0000
Subjectsgeophysics; deformation; crustal movements; velocity surveys; models; modelling; Charlevoix Seismic Zone; St. Lawrence Seismic Zone; global positioning system
Illustrationslocation maps; graphs; plots; tables
ProgramEastern Canada Geohazards Assessment Project, Public Safety Geoscience
AbstractContinuous Global Positioning System (CGPS) position time series from eastern North America constrain the pattern and magnitude of regional crustal deformation. Initial analysis delineates consistent uplift patterns, as expected from glacial isostatic adjustment (GIA) predictions, but the associated horizontal deformation is not definitive, in part due to the short time periods for a significant number of the available stations. We employ an eigenpattern decomposition in order to define a unique, finite set of deformation patterns for this continuous GPS data. Similar in nature to the empirical orthogonal functions historically employed in the analysis of atmospheric and oceanographic phenomena, the method derives the eigenvalues and eigenstates from the diagonalization of the correlation matrix using a Karhunen - Loeve expansion (KLE). The KLE technique is used to identify the important modes in both time and space for the CGPS data, modes that potentially include signals such as horizontal and vertical GIA, tectonic strain, and seasonal effects. Here we filter both the vertical and horizontal velocity patterns on different spatiotemporal scales in order to study the potential geophysical sources, after the
removal of correlated and random noise. The method is successful in disaggregating the linear vertical signal from more variable and less spatially correlated signals. The vertical and horizontal results are compared to the predictions of the ICE-3G GIA loading model with a number of plausible mantle viscosity profiles. The horizontal velocity analysis allows for qualitative differentiation between several potential GIA models and suggests that, with longer time series, this technique can be employed to remove correlated noise and improve estimates of crustal strain patterns and their sources.