Geological causes of recent (similar to 100 yr) vertical land movement in the Netherlands

Geodetic levelling data record differential vertical movements of the top o f the Pleistocene sands of up to 1.5 mm/year in the Netherlands over the la st century. We compare these movements to (a) mean tectonic, isostatic and compaction movements at time scales of millions of years obtained by backst ripping of Cenozoic stratigraphy, and Cb) estimates of recent (similar to 1 00 yr) movements from process modelling of isostasy (glacio- and hydro-isos tasy) and compaction. The process rates at lime scales of millions of years are insufficient to account for the geodetic observations by an order of m agnitude. The isostasy and compaction rates inferred for the last century a re also insufficient; they explain less than half of the observed movements . This suggests that the residual - observed rates less isostasy and compac tion estimates - which is interpreted to represent tectonic crustal deforma tion, constitutes an important contribution to present-day movements. The s urprisingly high rates of short-term tectonic vertical movements in a regio n which is relatively inactive, seismically, indicate that correction of ti de-gauge records for the glacio-isostatic signal alone does not yield an ap propriate measure of eustatic sea-level rise along the Dutch coast. (C) 199 8 Elsevier Science B.V. All rights reserved.