نوع مقاله : علمی -پژوهشی
نویسندگان
1 گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران مرکز پایش پیش نشانگرهای زمین لرزه، آزمایشگاه مرکزی دانشگاه تبریز، دانشگاه تبریز، تبریز، ایران
2 گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
IntroductionEarthquakes as natural disasters, are always considered to be a risk for human societies in terms of economy and life. Therefore, attempts to predict earthquakes have always been considered as a way of risk management. On the other hand, Iran is located in a critical seismic condition through the Alpine-Himalayan orogenic belt, which is one of the most seismic areas in the world. Talesh Mountains are located in North West of Iran, in the south of the Caucasus orogeny, east of the Anatoly, and north of the Zagros orogeny. Many minor and major earthquake faults such as Tabriz fault, North Anatoli fault, East Anatoli fault, Zagros main fault and Alborz Western faults are effective in this area.Materials and methodsEarthquake prediction by electric precursors, known as VAN method, is one of the most successful short-term methods of earthquake prediction. This method (VAN) is based on researching the changes in Geo-electric potentials, called seismic-electric signals (SES) which can be detected before earthquakes. SES could be shown in special locations (sensitive sites) and sensitive sites receive the SES as a selection from the seismic sources. Therefore, it is possible to estimate the location of the event up to 100 Kms far away. The magnitude of the progressive earthquake could be forecasted up to 0.7-unit tolerance in Richter scale. Professor Vrotsos that is the founder of the VAN method and director of the solid state physics in University of Athens has published more than 250 papers and 8 books in this subject. In the last two decades the VAN team developed the time series analysis to forecast earthquakes, called “Natural time analysis”. In this paper, according to this method, the occurrence of one earthquake M=5.5 is analyzed. Results and discussionSince 2014 a network of VAN stations were installed in NW Iran for recording and monitoring the Seismic Electric Signals (SES). Receiving and analyzing these signals, could help determine the magnitude, epicenter and time of impending earthquakes. This research investigates an SES received on 7th of August 2015 and application of natural time analysis to find out the time occurrence of the subsequent impending earthquake, in a time window less than a week. The natural time analysis indicates that this system reached the critical point, on September 3rd 2015 and subsequently on 4th of September 2015 the 5.5 Richter (MN) main shock occurred in Oghuz municipality in the Republic of Azerbaijan, at a distance of 310 km from Ispiran station. The important point is that this earthquake is the only earthquake greater than 5 Richter occurring in the study area in 6 months before and after this event. This confirms that this prediction wasn’t random.ConclusionSince 2014 a network of VAN stations were installed in NW Iran for recording and monitoring the Seismic Electric Signals (SES). Receiving and analyzing one of the signals, helped determine the magnitude, epicenter and time of impending earthquakes. This research investigates an SES received on 7 August 2015 and how to apply the natural time analysis to find out the occurrence of the subsequent impending earthquake, in a time window less than a week. The natural time analysis indicates that this system reached the critical point, on 3 September 2015 and subsequently On 4 September 2015 the 5.5 Richter (MN) main shock occurred in Oghuz municipality in the Republic of Azerbaijan, at a distance of 310 km from Ispiran station.
کلیدواژهها [English]