The present paper concerns long-term 3D monitoring of active fault structures in the Krupnik-Kresna seismic zone, SW Bulgaria with the use of extensometers TM71. The purpose is to establish the real rates of fault movements in the most seismically active area in Bulgaria. Three points were installed (B6 on Krupnik Fault, and K5 and K12 on Struma Fault), which indicate a recent activity. The fault movements are characteristic with “calm” periods, linear slips, accelerations and sudden displacements. Different regimes of dynamics have been established corresponding to different periods. The greatest dynamics is found at monitoring point B6 along Krupnik Fault: for the whole period of observation the trends are calculated as left lateral slip with 1.88 mm/a and a thrusting with 1.59 mm/a with high correlation coefficients. Co-seismic displacements from local and distant earthquakes were recorded. The significant impact was from M=7.4, 17 August, 1999, Izmit Earthquake, Turkey, showing a shortening of 8.34 mm, a right-lateral slip of 5.09 mm and a thrusting of 0.96 mm. After that, for a short period of time the regime of movement on fault was changed. Movements on the Struma system reveal lower rates. Both points show left-lateral movements, 0.28 mm/a at K5 and 0.09 mm/a at K12, and thrusting with 0.11 mm/a at K5 and 0.72 mm/a at K12., Nikolai Dobrev., and Obsahuje bibliografii
This paper represents the Romanian contribution in the frame of the European Co-operation "COST ACTION 625" and it is centered on an electromagnetic methodology for the natural hazard assessment due to both the seismic events and associated active faults which are considered to be sources of the most significant landslides in the Subcarpathian area (Romania). This methodology was established according to the geotectonic features of the seismic-active Vrancea zone and Provita de Sus landslide area. Subsequently, a specific approach regarding the electromagnetic precursory parameters, selected according to the temporal invariability criterion for a 2D geoelectric structure in non-seismic condition, taking into consideration their daily mean distribution versus intermediate depth seismic events recorded simultaneously, was elaborated. A similar electromagnetic technique conveying to additional parameters and models concerning the evolution in time of the landslide phenomena was also imposed, so that a disaster forecasting become possible., Dumitru Stanica and Maria Stanica., and Obsahuje bibliografii
A collaborative group between Greek, Polish, and Sl ovak colleagues installed a dense network of non-permanent GPS stations and extensometers to monitor active faults in the eastern part of the Gulf of Corinth, central Greece. The network includes eleven GPS stations across the Kaparelli fault and the Asopos rift valley to the east and two TM-71 extensometers that were installed on the Kaparelli fault plane. So far the G PS network has been measured in three campaigns within the last three years with very good accuracies (1-4 mm in the horizontal plane). Although it is early to draw conclusions on the velocity field and on strain patterns it can be noted that, the data from the extensometers demonstrate both fault-normal opening and shear motion. Given that the total offset on the Ka parelli fault is small, and the geological data suggesting a segmented character of this fault, we expect in the near fu ture to differentiate fault slip and strain accumulation among segments., Athanassios Ganas, Jaroslaw Bosy, Lubomir Petro, George Drakatos, Bernard Kontny, Marian Stercz, Nikolaos S. Melis, Stefan Cacon and Anastasia Kiratzi., and Obsahuje bibliografické odkazy
The Betic Cordillera, located at the westernmost end of the Mediterranean alpine belt, is deformed by overprinted folds and faults that produced the present-day relief since the Tortonian. In the frame of the COST 625 action, four sectors have been studied in the central part of the cordillera. In the Granad a Depression, the large NW-SE Padul normal fault deforms the SW periclinal end of the Sierra Nevada antiform. MT surveys in dicate the continuity in depth of high and low angle normal seismogenic faults and the presence of act ive detachment faults. In Tabernas regi on a good example of interaction between a N W-SE propagating normal fault, E-W strike-slip faults and the fold system is studied. In the Sierra Tejeda-Zafarraya and in the Balanegra-Sierra de Gádor areas, two new GPS networks ha ve been installed to determine the interaction and the development of large antiformal struct ures and normal faults with E-W and NW-SE orientations. However, taking into account the low tectonic activity of the studi ed region, a period of more than 5 year could be needed to determine with enough accuracy the development rate of the structures., Jesús Galindo-Zaldívar, Antonio Gil, Carlos Sanz de Galdeano, Stefan Shanov and Dumitru Stanica., and Obsahuje bibliografické odkazy