Akademik Veri Yönetim Sistemi
Geomechanics and Geophysics for Geo-Energy and Geo-Resources, cilt.5, sa.1, ss.253-270, 2019 (SCI-Expanded)
An earthquake of magnitude 6.6 (ML) and 7.2 (Mw) occurred at 13: 41 p.m.
local time on October 23, 2011 in the western of the Erçek Lake and
about 20 km away from the city center of Van, Turkey (EQE-KOERI in The
October 23, 2011 Van, Turkey earthquake (Mw = 7.2). Technical report.
İstanbul, 2011).
The earthquake was recorded using by the 22 accelerometers in the
stations belong to National Strong Motion Observation Network (DEMP 2011.
Republic of Turkey prime ministry disaster and emergency management
presidency, Earthquake Department, 23-Oct-2011 Van Earthquake Report).
The distance of these stations from the earthquake epicenter varies
between 42 and 590 km. The closest station to the earthquake is
Van–Muradiye acceleration-meter station and measured higher values of
acceleration in N–S component, E–W direction and vertical direction are
178 cm/s2, 168.5 cm/s2 and 78.5 cm/s2,
respectively. The highest acceleration value was recorded at the N–S
component in Van–Muradiye acceleration-meter station. Seismic intensity
values calculated by using these acceleration values and for Van-Merkez
earthquake, maximum intensity is predicted as IX whereas the maximum
intensity value is predicted as VI for Van-Edremit earthquake. It is
understood that the Everek Fault with approximately E–W direction has
caused the earthquake. Focal mechanism solutions of Mw: 7.2 earthquakes
reveal E–W oriented thrust fault mechanism. Since there were no marker
to thrust faulting in the field as fault rupture, morphological
indicators, other effects of earthquake like mass movements show that
E–W oriented thrust fault named as “Everek Fault” is the primary source
of this event. The most important proof of this idea was the
aftershocks. Due to the Bitlis station is located the Southwestern edge
of the fault and the high accelerations in the E–W component, it is seen
that the forward directivity effect in the station records. The time of
the earthquake is one of the important parameters determining the
structural damage. It is also one of the important parameters of the
strong motion earthquakes. The acceleration values greater than 50 gal
(cm/s2) in the Van–Muradiye station has continued
approximately 16 s. The area has important seismic activities and
complex fault systems. The acceleration record in the Van–Muradiye
station is very important to seismology of strong ground motion. When
records of Muradiye and Van Stations area analyzed in terms of response
spectra, both ground motions are below the design spectra defined for
1st degree earthquake zone. Buildings in Van city and Erciş district
generally consists of 4–8 storey concrete structures, which is very
common in Turkey. Therefore, due to the higher ground acceleration is
greater than expected empirical values, the major damages has occurred
in buildings.