Absolute gravity changes at Polish gravimetric fundamental network and its interpretation in hydrological, hydrogeological and geodynamical and anthropogenic contexts
21/09/2016 | 09:30 | Session 4: On the ground and airborne gravimetry
Author(s): Marcin Barlik, Andrzej Pachuta and Tomasz Olszak
Marcin Barlik, Andrzej Pachuta and Tomasz Olszak
The previous Polish gravity control (POGK) established in the last few years of 20th century was spanned on 12 absolute gravity stations located in 90’s and surveyed with four different types of absolute gravimeters. New gravity control has been established in 2012-2014 and consist of 29 fundamental points (surveyed with the FG5 gravimeter), and 169 base points (surveyed with the A10 gravimeter). In the new structure 21 stations of fundamental control was pre-existing POGK network and other points, with right stabilization and history of absolute g measurements. Determination of g made in 2014 allow comparison of the gravity to previous values, reaching even 90s. The collected material is characterized by great diversity, however, because at the time some of the points made observations only twice, sometimes at intervals of several years. It is also heterogeneous in terms of the instruments used.
In the presentation will be analyzed the full list of absolute g changes on all points of the Polish fundamental stations done in 2014. Time series will be verified by the metrological parameters, resulting from international and local calibration of absolute gravimeters meetings. Analysis of obtained changes will be performed in hydrological aspects in the sense of a global effect based on GLDAS model and hydrogeological aspects, based on results of monitoring ground water levels close to the gravity stations. This monitoring is provided by national geological survey even with daily time resolution. For a number of points will be indicated anthropogenic factor. All effects gives a possibilities to separation observed g changes by instrumental, physical and geometrical parts at the end.