This proposal sets to establish two seismic arrays that will serve
as models in Turkey for the future, and to increase the density of
instruments in the national strong motion network at selected urban
zones. This proposal is limited only to describing a small part of
a wider system that will be enhanced mainly through Turkish national
resources. The successful initiation of these arrays that will record
ground motions from both small- and large-magnitude earthquakes will
serve as leverage for similar arrangements at other suitable locations.
The arrays will become incorporated into the national system in operation
in Turkey, and serve to enhance its utility. A national strong motion
arrays council consisting of experts in this field should establish
the national objectives, and promote the idea nationally. We plan
to form this council quickly so that their counsel is available during
the planning and installation stages.
With heightened odds for a renewed major earthquake near the western
end of the North Anatolian Fault estimated to affect Istanbul, one
of these arrays would be near Yalova, a city 40 km to the southeast,
and extend linearly to Bursa, about 65 km to the south-west of Yalova.
(The rupture of the 17 August 1999 earthquake did not reach Yalova,
but it is reasoned that the next segment to break will include it.)
The vicinity of Aydýn-Denizli, 100 km east of Izmir along the
Menderes river valley, is considered for the second array. These two
locations are in transform and normal fault mechanism regions, respectively.
Yalova, Bursa, Izmir, Aydin and Denizli are the candidate cities for
deploying instruments to complement the currently existing isolated
Among significant objectives is also the training of young seismologists
and engineers in the design, installation, and maintenance of these
array as well as utilization of the data that may be recorded on them.
Most of these younger staff are part of the Earthquake Research Division
of the Turkish General Directorate of Disaster Affairs, the national
agency responsible for the operation of the national system. Qualified
young academicians from METU and ITU will also be trained for strong
motion instrumentation and operation. With the US planning to spend
$175 million to establish an Advanced National Seismic System that
will require $47 million annually to maintain, the global importance
of protection of lives and infrastructure against the seismic peril
is confirmed. Investment in these instruments may pay off for decades
with the knowledge to build safer structures. Large earthquakes that
are not properly recorded are irreplaceable, missed opportunities
that can result in delays of decades before a similar earthquake is
recorded. The practice of risk management in the country will benefit
from the information that could be generated from these arrays.