Recent results based on continuous GPS observations of the GIA process in Fennoscandia from BIFROST

Abstract We present the latest 3D velocity field of the Fennoscandian glacial isostatic adjustment (GIA) process from BIFROST. It is derived from more than 4800 days (13 years) of data at more than 80 permanent GPS sites. We use the GAMIT/GLOBK and the GIPSY/OASIS II software packages for GPS analysis and compare the results. The solution has an internal accuracy at the level of 0.2 mm/year (1 sigma) for horizontal velocities at the best sites. We also present a revised GIA prediction model. At the best sites, the optimal model agrees with the observations to within 0.4 mm/year. However, the model systematically overpredicts the magnitude of horizontal rates in the north. We discuss limitations in computed and presented GNSS station velocities, where especially possible instability over time causing non-linear pattern in vertical time series are considered. In extension, preliminary results from an investigation applying revised analysis strategies on a sparse subset of the database are presented, indicating possible improvements for the future.

[1]  Yehuda Bock,et al.  Error analysis of continuous GPS position time series , 2004 .

[2]  Camilla Granström,et al.  Site-Dependent Effects in High-Accuracy Applications of GNSS , 2006 .

[3]  Donald F. Argus,et al.  Defining the translational velocity of the reference frame of Earth , 2007 .

[4]  T. Dixon,et al.  Noise in GPS coordinate time series , 1999 .

[5]  J. Johansson,et al.  New Results Based on Reprocessing of 13 years Continuous GPS Observations of the Fennoscandia GIA Process from BIFROST , 2009 .

[6]  J. Zumberge,et al.  Precise point positioning for the efficient and robust analysis of GPS data from large networks , 1997 .

[7]  Michael B. Heflin,et al.  The effect of the second order GPS ionospheric correction on receiver positions , 2003 .

[8]  Zuheir Altamimi,et al.  Specifications for reference frame fixing in the analysis of a EUREF GPS campaign , 1998 .

[9]  J. Johansson,et al.  Continuous GPS measurements of postglacial adjustment in Fennoscandia 1. Geodetic results , 2002 .

[10]  Jan M. Johansson,et al.  Continuous GPS measurements of postglacial adjustment in Fennoscandia: 2. Modeling results: FENNOSCANDIAN GPS MODELING RESULTS , 2004 .

[11]  R. Nikolaidis.  Observation of geodetic and seismic deformation with the Global Positioning System , 2002 .

[12]  M. Ekman.  A consistent map of the postglacial uplift of Fennoscandia , 1996 .

[13]  S. Williams.  The effect of coloured noise on the uncertainties of rates estimated from geodetic time series , 2003 .

[14]  J. Johansson,et al.  BIFROST: Noise properties of GPS time series , 2007 .

[15]  T. van Dam,et al.  Effects of atmospheric pressure loading and seven-parameter transformations on estimates of geocenter motion and station heights from space geodetic observations , 2005 .

[16]  M. Ekman,et al.  Recent postglacial rebound, gravity change and mantle flow in Fennoscandia , 1996 .

[17]  Galina Dick,et al.  Impact of GPS satellite antenna offsets on scale changes in global network solutions , 2005 .

[18]  J. Mitrovica,et al.  Postglacial sea-level change on a rotating Earth , 1998 .

[19]  J. Mitrovica,et al.  Near-field hydro-isostasy: the implementation of a revised sea-level equation , 1999 .

[20]  Jan M. Johansson,et al.  An improved and extended GPS-derived 3D velocity field of the glacial isostatic adjustment (GIA) in Fennoscandia , 2007 .

[21]  Markku Poutanen,et al.  Use of the Finnish Permanent GPS Network (Finnnet) in Regional GPS Campaigns , 1998 .

[22]  Thomas A. Herring,et al.  MATLAB Tools for viewing GPS velocities and time series , 2003 .

[23]  Walter H. F. Smith,et al.  New, improved version of generic mapping tools released , 1998 .

[24]  T. Herring,et al.  Introduction to GAMIT/GLOBK , 2006 .

[25]  G. Milne.  Space-geodetic constraints on glacial isostatic adjustment , 2001 .

[26]  Paul Johnston,et al.  Sea‐level change, glacial rebound and mantle viscosity fornorthern Europe , 1998 .

[27]  Mike P. Stewart,et al.  Aliased tidal signatures in continuous GPS height time series , 2003 .

[28]  Z. Altamimi,et al.  ITRF2005 : A new release of the International Terrestrial Reference Frame based on time series of station positions and Earth Orientation Parameters , 2007 .

[29]  Paul Tregoning,et al.  Impact of solid Earth tide models on GPS coordinate and tropospheric time series , 2006 .

[30]  Harald Schuh,et al.  Effect of different tropospheric mapping functions on the TRF, CRF and position time-series estimated from VLBI , 2007 .

[31]  Soren W. Henriksen,et al.  The Use of artificial satellites for geodesy , 1972 .

[32]  M. Sideris,et al.  Observing our Changing Earth , 2009 .

[33]  Simon D. P. Williams,et al.  CATS: GPS coordinate time series analysis software , 2008 .

[34]  Zuheir Altamimi,et al.  ITRF2000: A new release of the International Terrestrial Reference Frame for earth science applications , 2002 .

[35]  F. Webb,et al.  An Introduction to the GIPSY/OASIS-II , 1993 .

[36]  A. Niell.  Global mapping functions for the atmosphere delay at radio wavelengths , 1996 .

[37]  Jan M. Johansson,et al.  Fennoscandian strain rates from BIFROST GPS: A gravitating, thick-plate approach , 2010 .

[38]  Derek D. Lichti,et al.  Investigating the propagation mechanism of unmodelled systematic errors on coordinate time series estimated using least squares , 2005 .

[39]  E. Ivins,et al.  Upper mantle dynamics and quaternary climate in cratonic areas (DynaQlim)—Understanding the glacial isostatic adjustment , 2010 .

[40]  H. Schuh,et al.  Global Mapping Function (GMF): A new empirical mapping function based on numerical weather model data , 2006 .