Department of Gravimetry and Geodynamics

Web page of the Department of Earth Science Institute SAS

Geodynamics

Research devoted to the study of earth tides and crustal deformations, monitoring and interpretation of extensometric measurements. Special attention is paid to the aperiodic component of the extensometric data with implications to slow tectonic crustal deformations, and to the derivation of rheological properties of the earth crust.
We deal also with interpretation of surface deformations and gravity changes observed in active or awakening volcanic areas.

Researchers from the Earth Science Institute went to Tenerife in June 2016 to carry out volcano-gravimetric field work. The objective of the observation campaign was to measure in-situ vertical gradients of gravity (VGGs) for the sake of verifying the numerically predicted (modelled) extreme values of the VGG. The crew comprised Peter Vajda and Pavol Zahorec of the Department of Gravimetry and Geodynamics of our institute, as well as Juraj Papčo of the Department of Geodesy of the Slovak Technical University in Bratislava. The campaign span one week (20–28 June, 2016). This field work campaign was conducted successfully and the acquired data seem promising.

 

Measurable temporal changes of gravity and deformations of earth's surface are indicators of dynamic processes inside the earth, such as those associated with movements of magma preceding volcanic eruptions. The observation, analysis and interpretation of surface gravity changes and vertical displacements of the topographic surface contribute to understanding the physics of magma reservoirs and the processes associated with volcanic activity.

Peter Vajda1, Ilya Prutkin2, Robert Tenzer3 and Gerhardt Jentzsch2

1 Geophysical Institute, Slov. Academy of Sci., Bratislava, Slovakia, This email address is being protected from spambots. You need JavaScript enabled to view it.
2 Institute of Geosciences, Jena University, Jena, Germany
3 National School of Surveying, University of Otago, Dunedin, New Zealand

Gravity changes observed around Teide (Tenerife) between May 2004 and July 2005, due to the suspected reawakening of the volcano, were reinterpreted by us. Our objective was to seek multiple sources of the observed gravity signal. Our interpretation is based on the decomposition of the gravity signal into shallow and deep fields, and subsequent inversion of each field by means of 3D line segments. The shallow (near-surface) segments are interpreted as hydrothermal fluids. A short deep segment was found at the depth of about 6 km below sea level, interpreted as magma injection. Our results indicate that the 2004 volcanic unrest at the Central Volcanic Complex of Tenerife was a failed eruption.