Seismic Z Factors and Intensity Provinces of Iranian Earthquakes.

Based on, historical seismicity, position
of 19-century instrumental epicenters,
fault zones, relation of seismicity
with active faults, and structural
geology, statistics of earthquake
activites, model studies for estimation
of acceleration, and other
information of intensities of Iranian
earthquakes, and for simplicity
in the usage, the country is divided
into two Intensity Provinces. In
the first province, an earthquake
with intensity VIII or more on Modified
Mercalli scale is probable ,and
for this province the seismic Z factor
of 1 is suggested. Most of Iranian
major cities are located within
this province.
In the second province, an earthquake
with intensity VII or less is probable;
for this province the seismic Z
factor of 0.75 is suggested. The cities
of Esfahan, Abadan, Khonin-Shahr,(old
Khoram-Shahr), Zabol,Bijar, Miandoab,
and Takab are located within the second
province.