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IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS014 Poster presentation 2285
Distribution of Seismic Energy Released in Iran
Mrs. Nadia Tahernai
Geophysics Ph.d student IASPEI
Dr. Mohammad Reza Gheitanchi
Iran is located along Alpine- Himalayan belt, and one of the seismically active regions in the world.
Seisimicity of Iranian plateau during the past 40 years from 1964 to 2004 is investigated in four 10-year
successive time interval by analyzing about 1260 earthquakes in the region. The area was divided into
quadrangles each covering half a degree of latitude and longitude, and the seismic energy and
associated strain released of earthquakes which occurred within each quadrangle in different periods
were computed and combined. The comparison of seismic energy maps indicates that the major zones
of activity are, Zagros, Alborz and east-central Iran. Small plates in central Iran, the southern Caspian
Sea, and Lut also show noticeable stability. The seismic gaps in early intervals were filled up by the
seismic activities during the following time intervals. The maps of epicenteral distribution and the
frequency - magnitude diagrams during successive time intervals show that Alborz and Lut regions were
seismically active and characterized by significant earthquakes. Zagros had a more regular pattern of
seismic activity and experienced moderate and small earthquakes. The different seismic patterns
suggest that the physical properties of fault systems are different in different regions and the crust is
inhomogeneous in Iranian plateau.
Keywords: seismic energy, iran, seisimicity