A GNSS velocity field for geophysical applications in Fennoscandia
Artikel i vetenskaplig tidskrift, 2021

In Fennoscandia, tectonics, Glacial Isostatic Adjustment (GIA), and climatic changes cause ongoing crustal deformation of some millimetres per year, both vertically and horizontally. These displacements of the Earth can be measured to a high degree of precision using a Global Navigation Satellite System (GNSS). Since about three decades, this is the major goal of the Baseline Inferences for Fennoscandian Rebound, Sea-level, and Tectonics (BIFROST) project. We present a new velocity field for an extended BIFROST GNSS network in the ITRF2008 reference frame making use of the GNSS processing package GPS Analysis Software of MIT (GAMIT). Compared to earlier publications, we have almost doubled the number of stations in our analysis and increased the observation time span, thereby avoiding the early years of the network with many instrument changes. We also provide modelled vertical deformation rates from contributing processes, i.e. elastic deformation due to global atmospheric and non-tidal ocean loading, ice mass and hydrological changes as well as GIA. These values for the vertical component can be used for removal of these contributions so that the residual uplift signal can be further analysed, e.g., in the context of local or regional deformation processes or large-scale but low-magnitude geodynamics. The velocity field has an uplift maximum of 10.3 mm/yr in northern Sweden west of the Gulf of Bothnia and subsidence exceeding 1 mm/yr in northern Central Europe. The horizontal velocity field is dominated by plate motion of more than 20.0 mm/yr from south-west to north-east. The elastic uplift signal sums up to 0.7–0.8 mm/yr for most stations in Northern Europe. Hence, the maximum uplift related to the past glaciation is ca. 9.6 mm/yr. The residual uplift signal after removal of the elastic and GIA contribution may point to possible improvements of the GIA model, but may also indicate regional tectonic and erosional processes as well as local deformation effects. We show an example of such residual signal discussing potential areas of interest for further studies.

GNSS

Land uplift

Velocity field

Crustal deformation

Glacial isostatic adjustment

BIFROST

Författare

Halfdan Pascal Kierulf

Kartverket

Universitetet i Oslo

Holger Steffen

Lantmäteriet

Valentina R. Barletta

Danmarks Tekniske Universitet (DTU)

Martin Lidberg

Lantmäteriet

Jan Johansson

Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium, Rymdgeodesi och geodynamik

Oddgeir Kristiansen

Norges miljø- og biovitenskapelige universitet

Lev Tarasov

Memorial University of Newfoundland

Journal of Geodynamics

0264-3707 (ISSN)

Vol. 146 101845

Ämneskategorier

Meteorologi och atmosfärforskning

Naturgeografi

Multidisciplinär geovetenskap

DOI

10.1016/j.jog.2021.101845

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Senast uppdaterat

2021-05-18