Akademik Veri Yönetim Sistemi
New Trends in Geophysics and Engineering, İstanbul, Türkiye, 7 - 09 Kasım 2018, ss.1-4
In
this study, we have determined the average crustal and the uppermost mantle shear
velocities around the Lake Van Region (Eastern Turkey). For this purpose, we have
used to the fundamental mode interstation Rayleigh wave phase velocities. The
phase velocities were calculated from the regional earthquakes recorded by
Kandilli Observatory and Earthquake Research Institute stations. The earthquakes
were downloaded by using European
Integrated Data Archive. Considering
back azimuth differences of each source and station path, three different
broadband station pairs (GURO-VANB, AGRB-VANB and MLAZ-VANB) and a few
earthquakes were selected to determine the 1-D S-wave structures by using
an interstation method (slant stacking technique). The linearized least squares
algorithm was helped to define the shear-velocity model,
which is the best fit the observed phase velocity dispersion curve.
The normalized statistical resolution matrix was calculated to
measure the reliability of the solution. Inversion results show that the solution
quality of the upper crust is not good because of the high resolution lengths.
The average shear-wave velocities of the lower crust are nearly 3.5 km/s. It is
concluded that the low-velocity zone shown in the lower crust may be associated
with widespread volcanism. According to the last 2-D S-wave velocity models,
the moho discontinuity is ~42 km, and shear velocities range between 3.6 to 4.2
km/s. In addition, the uppermost mantle (~45–70 km) velocities are slower than
globally earth models, and it is probably connected with hot asthenospheric
material