بررسی ارتباط تغییرات زمانی غلظت گاز رادون با پس‌لرزه‌های زمین‌لرزه بم به‌‌کمک شبکه عصبی آدالاین

نوع مقاله : مقاله پژوهشی‌

نویسندگان

1 موسسه ژئوفیزیک دانشگاه تهران، ایران

2 دانشگاه تحصیلات تکمیلی صنعتی کرمان، ایران

چکیده

غلظت گاز رادون پس از زمین‌لرزه بم ( 5/10/1382، 8/6)، در ایستگاهی واقع در غرب بروات در بازه‌های زمانی 10 دقیقه‌ای ثبت شد. برای بررسی ارتباط زمانی بین تغییرات میزان غلظت گاز رادون و وقوع پس‌لرزه‌های زمین‌لرزه بـم، تاثیر پارامترهای جوّی دما، فشار جوّی و رطوبت خاک روی میزان غلظت گاز رادون با استفاده از شبکه عصبی خطی آدالاین و الگوریتم ژنتیک کمینه شد. تجزیه‌وتحلیل داده‌های غلظت گاز رادون اندازه‌گیری‌شده در بـم نشان می‌دهد که شبکه‌عصبی آدالاین قادر به شناسایی تغییرات خطی غلظت گاز رادون ناشی از پارامترهای جوّی از بی‌هنجاری‌های حاصل از پس‌لرزه‌ها است.
 
 

کلیدواژه‌ها

عنوان مقاله [English]

Analysis of temporal variations of radon concentration and aftershocks of Bam Earthquake using Adaline neural network

نویسندگان [English]

  • Forough Keshvari 1
  • Noorbakhsh Mirzaei 1
  • Ali Negarestani 2
1
2
چکیده [English]

Temporal variations of radon concentration in soil and groundwater might be one of the few promising precursors for earthquake prediction. In this study, the relation between radon concentration and aftershocks of Bam Earthquake (26/12/2003, Ms=6.8) has been investigated. The radon monitoring station was located at 29°N and 58.4°E, precisely on Bam Fault where there have been high occurrences of seismic activities. The study was carried out using an active method involving an Alpha Gurad PQR2000, Alpha Pump and relative accessories which is a device capable of accurately measuring radon concentrations every 10 minutes. Air was being pumped from ground to the measuring system with a flux of 1 L/min. Forced air suction was chosen in order to avoid stratification effects, very common for radon, due to its elevated weight. Radon-monitoring sites are usually chosen in the areas where higher concentrations of radon in the surface soil layer can be expected. For this propose, the radon monitoring site was placed exactly on Bam Fault, which was placed between Bam and Baravat Cities. Radon concentration monitoring data was collected in soil at 90cm depth exposed for a period of 90 days, every 10 minutes. Radon concentration changes are not only controlled by an earthquake, but they are also controlled by meteorological parameters at the radon monitoring site such as rainfall, soil moisture, temperature and atmospheric pressure. Therefore, in order to use radon variations as a reliable earthquake precursor, we must be able to differentiate changes that are due to earthquake from those which are not.
    In recent years, artificial neural networks have become very powerful, intelligent tools, used widely in signal processing, pattern recognition and other applications. The main advantages of the method are the learning capability for developing new solutions to problems that are not well defined, an ability to deal with computational complexities, a facility of carrying out quick interpolative reasoning, and finding functional relationships between sets of data.
    We have used a modified Adaline structure to estimate the temporal variation of radon concentration related to environmental parameters. This enables us to differentiate the changes due to phenomena in the earth such as earthquakes from those of environmental parameters. Radon concentration data obtained from our site and meteorological parameters measured in meteorological station of Bam were processed by the adaptive linear neural network, Adaline. It was indicated that the linear neural network was able to differentiate linear variations of radon concentration caused by the meteorological parameters from those arose from anomaly phenomena due to the aftershocks.
 
 

کلیدواژه‌ها [English]

  • Bam earthquake
  • earthquake precursors
  • Neural Network
  • radon emission

مراجع

نگارستانی، ع.، 1381، تجزیه‌وتحلیل هوشمندانه زمین‌لرزه از طریق تشخیص تغییرات انتشار گاز رادون و عوامل محیطی تاثیرگذار (دما، فشار، بارندگی، ...): پایان‌نامه دکتری، دانشگاه صنعتی امیرکبیر.
Asada, T., 1982, Earthquake Prediction Techniques: Their Application in Japan: University of Tokyo Press.
Berberian, M., 2005, The 2003 Bam Urban earthquake: A predictable seismotectonic pattern along the Western Margin of the Rigid Lut Block, Southeast Iran: Earthquake Spectra, 21, S35-S99.
Einarsson, P., Theodorsson, P., Hjartardottir, A. R., and Guojonsson, G. I., 2008, Radon change associated with the earthquake sequence in June 2000 in the South Iceland seismic zone: Pure. Appl. Geophys., 165, 63-74.
Elmaghraby, E. K., and Lotfy, Y. A., 2009, Differentiation between earthquake radon anomalies and those arising from nuclear activities: Applied Radiation and Isotopes, 67, 208-211.
Fleischer, R. L., 1997, Radon and earthquake prediction: Radon Measurements by Etched Track Detectors, in Durrani, S. A., and Ilić, R., eds., Applications in Radiation Protection, Earth Sciences and the Environment: World Scientific, Singapore, 285–299.
GSI, 1993a, Geological Map of Iran, 1:100,000 Series, Sheet 7648-Bam, Geological Survey of Iran, Tehran.
GSI, 1993b, Geological Quadrangle Map of Bam, 1:250,000. Geological Quadrangle of Iran No. J11. Geological Survey of Iran, Tehran.
Hickman, S., Sibson, R., and Bruhn, R., 1995, Introduction to special section: mechanical involvement of fluids in faulting: J. Geophys. Res., 100, 12831–12840.
Holland, J., 1975, Adaptation in Natural and Artificial System: University of Michigan Press.
Igarashi, G., Saeki, S., Takahata, N., Sumikawa, K., Tasaka, S., Sasaki, Y., Takahashi, M., and Sano, Y., 1995, Groundwater radon anomaly before the Kobe earthquake in Japan: Science, 269, 60–61.
King, C. Y., Zhang, W., and King, B. S., 1993, Radon anomalies on three kinds of faults in California: Pure. Appl. Geophys., 141, 111–124.
Kulahci, F., Inceoz, M., Dogru, M., Aksoy, E., and Baykara, O., 2009, Artificial neural network model for earthquake prediction with radon monitoring: Applied Radiation and Isotopes, 67, 212-219.
Miklavcic, I., Radolic, V., Vukovic, B., Poje, M., Varga, M., Stanic, D., and Planinic, J., 2008, Radon anomaly in soil gas as an earthquake precursor: Applied Radiation and Isotopes, 66, 1459-1466.
Monnin, M. M., 2001, Radon over volcanic and seismic areas, in Frontasyeva, M. V., Perelygin, V. P., and Vater, P., eds., Radionuclides and heavy metals in Environment: Kluwer Academic Publishers, 319–330.
Negarestani, A., Setayeshi, S., Ghannadi-Maragheh, M., and Akashe, B., 2002, Layered neural networks based analysis of radon concentration and environmental parameters in earthquake prediction: Journal of Environmental Radioactivity, 62, 225–233.
Negarestani, A., Setayeshi, S., Ghannadi-Maragheh, M., and Akashe, B., 2003, Estimation of the radon concentration in soil related to the environmental parameters by a modified Adaline neural network: Applied Radiation and Isotopes, 58, 269–273.
Pinault, J. L., and Baubron, J. C., 1996, Signal processing of soil-gas radon, atmospheric pressure, moisture and soil temperature data: a new approach for radon concentration modeling: J. Geophys. Res., 101, 3157-3171.
Ramola, R. C., Prasad, Y., Prasad, G., Kumar, S., Choubey, V. M., 2008, Soil-gas radon as seismotectonic indicator in Garhwal Himalaya: Applied Radiation and Isotopes, 66, 1523-1530.
Talebian, M., Fielding, E. J., Funning, G. J., Ghorashi, M., Jackson, J., Nazari, H., Parson, B., Priestley, K., Rosen, P. A., Walker, R., and Wright, T. J., 2004, The 2003 Bam Iran earthquake: rupture of a blind strike-slip fault: Geophys. Res. Lett., 31, L11611.
Tatar, M., Hatzfeld, D., Moradi, A. S., Paul, A., Farahbod, A. M., and Mokhtari, M., 2004, Aftershock study of the 26 December 2003 Bam earthquake: Journal of Seismology and Earthquake Engineering, Special Issue on Bam Earthquake, 23-31.
Ulomov, V. I., and Mavashev, B. Z., 1967, A precursor of a strong tectonic earthquake: Dokl. Akad. Nauk. USSR, Earth Sci. Sect., 176, 9-11.
Wang, R., Xia, Y., Grosser, H., Wetzel, H. U., Kaufmann, H., and Zschau, J., 2004, The 2003 Bam (SE Iran) earthquake: Precise source parameters from satellite radar interferometry: Geophys. J. Int., 159, 917-922.
Yakovleva, V. S., 2003, The radon flux density from the Earth’s surface as an indicator of a seismic activity: Proceedings of ICGG7, Extended Abstracts, 28-30.
مجله ژئوفیزیک ایران
دوره 6، شماره 3
آذر 1391
صفحه 113-126

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