Contract no. 1028/19.01.2009 Programme: "IDEI"

              

ELECTROMAGNETIC STUDIES ON INTERPARAMETRIC RELATIONSHIPS CHARACTERISING LANDSLIDES ASSOCIATED TO SEISMIC EVENTS

ro eng

| Home | General data | Project description | Objectives / Activities | Personnel | Results |

 

RESULTS

 
 
Nat. Hazards Earth Syst. Sci., 11, 3151-3156, 2011
www.nat-hazards-earth-syst-sci.net/11/3151/2011/
doi:10.5194/nhess-11-3151-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.

Anomalous pre-seismic behavior of the electromagnetic normalized functions related to the intermediate depth earthquakes occurred in Vrancea zone, Romania

D. Stanica and D. A. Stanica
Institute of Geodynamics of the Romanian Academy, Bucharest, Romania

Abstract. In this paper the electromagnetic normalized functions (ENF), carried out in ULF band, have been analyzed in correlation with intermediate depth seismic events occurring in Vrancea zone. To confirm the relationship between anomalous, pre-seismic behavior and an imminent earthquake, a methodology based on the temporal invariability criterion of ENF for a 2-D structure, in non-geodynamic conditions, has been used. The electromagnetic data were collected at the Geodynamic Observatory Provita de Sus (GOPS), placed on the Carpathian electrical conductivity anomaly where the epicentral distance is about 100 km, and the National Geophysical Observatory Surlari (NGOS) taken as a reference and located 140 km from the Vrancea zone. The daily mean distributions of the ENF over a span of several months in 2009, carried out at GOPS, exhibit significant enhancements from the normal trend before all the earthquakes with magnitudes higher than 4. Two correlations between the magnitudes of seismic events and Bzn have to be highlighted: (i) an earthquake of M ≥ 4 is expected to occur when Bzn ≥ 1.846; (ii) meanwhile, the anomalous behaviour of Bzn ≥ 1.851 may be use as pre- seismic value for an earthquake of M ≥ 5. The lead time is closed on 7–15 days before earthquakes occurrence.

Full Article (PDF, 2454 KB)   Special Issue

Citation: Stanica, D. and Stanica, D. A.: Anomalous pre-seismic behavior of the electromagnetic normalized functions related to the intermediate depth earthquakes occurred in Vrancea zone, Romania, Nat. Hazards Earth Syst. Sci., 11, 3151-3156, doi:10.5194/nhess-11-3151-2011, 2011.   Bibtex   EndNote   Reference Manager    XML
 
 

Institute of Geodynamics “Sabba S. Stefănescu” of the Romanian Academy