Repeated absolute gravity measurements for monitoring slow intraplate vertical deformation in Western Europe
Artikel i vetenskaplig tidskrift, 2011

In continental plate interiors, ground surface movements are at the limit of the noise level and close to or below the accuracy of current geodetic techniques. Absolute gravity measurements are valuable to quantify slow vertical movements, as this instrument is drift free and, unlike GPS, independent of the terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at 8 stations along a southwest-northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformations in the area. The AG measurements, repeated once or twice a year, can resolve elusive gravity changes with a precision better than 3.7 nm/s²/yr (95% confidence interval) after 11 years, even in difficult conditions. After 8-15 years (depending on the station), we find that the gravity rates of change lie in the [-3.1, 8.1] nm/s²/yr interval and result from a combination of anthropogenic, climatic, tectonic, and Glacial Isostatic Adjustment (GIA) effects. After correcting for the GIA, the inferred gravity rates and consequently, the vertical land movements, reduce to zero within the uncertainty level at all stations except Jülich (due to man-induced subsidence) and Sohier (possibly, an artifact due to the shortness of the time series at that station).

Continental Deformation

Absolute gravimeter

GIA

Northwestern Europe

Vertical land movements

Gravity

Författare

Michel van Camp

Royal Observatory of Belgium

Institut de Physique du Globe de Paris

Olivier de Viron

Institut de Physique du Globe de Paris

Hans-Georg Scherneck

Chalmers, Rymd- och geovetenskap, Rymdgeodesi och geodynamik

Klaus Hinzen

Universität zu Köln

Simon D. P. Williams

National Oceanography Centre Southampton

Thomas Lecocq

Royal Observatory of Belgium

Yves Quinif

Université de Mons

Thierry Camelbeeck

Royal Observatory of Belgium

Journal of Geophysical Research

0148-0227 (ISSN)

Vol. 116 B8 B08402- B08402

Fundament

Grundläggande vetenskaper

Ämneskategorier

Geofysik

DOI

10.1029/2010JB008174

Mer information

Senast uppdaterat

2018-03-29