Authors:Tímea Kocsis, Ilona Kovács-Székely, and Angéla Anda
the Department of Meteorology and Water Management of the University of Pannonia Georgikon Faculty (Keszthely). This data set is special because few stations in Hungary have continuousmeasurements over more than 140 years with detailed historical
In Hungary there are borehole tiltmeters used for monitoring tectonic movements and landslides. These investigations need long time continuous measurements. The Model 722A tiltmeters of Applied Geomechanics Inc. are fastened to the ground by tamped sand in the borehole. In some cases the boreholes become untight and it was thought that in this case the ground water seeping into the borehole could loosen the tamped sand causing a bad coupling between the tiltmeter and the ground. It was proved by laboratory test that the ground water and the variation of its level does not change the coupling of the instrument to the ground. In this paper the description of the test made at the Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences and the results of the measurements are given.
Based on continuous measurements of the atmospheric electric potential gradient (PG) in the Geophysical Observatory at Nagycenk (Hungary), selected data of the interval 1993-2003 have been analysed. The analyses were particularly aimed at the confirmation of global signatures found by a previous study using PG data of a shorter period. The present results have proved that the seasonal variation of PG (generally showing a winter maximum and a summer minimum at land stations) might really be modified at Nagycenk by a secondary maximum appearing in summer-time of certain years. Further analyses have also been carried out by using data derived from measurements with two different apparatus, however, covering a shorter period. Moreover, a connection between the occasional summer peaks of PG and the occurrences of warm El Niño periods might also be suggested on the basis of results derived from selected PG data and appropriate MEI Indices showing the time history of the ENSO phenomenon for the interval 1993-2003.