The Upper-Lower Crust Structure based on the P-Receiver Functions underneath ARPR and MALT stations, SE Turkey

Alkan H., Öztürk S.

10th International Mardin Artuklu Scientific Researches Conference MAY 19-21, 2023 / MARDIN, TÜRKİYE, Mardin, Türkiye, 19 - 21 Mayıs 2023, ss.1-10

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: Mardin
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.1-10
  • Van Yüzüncü Yıl Üniversitesi Adresli: Evet

Özet

The receiver Function technique is generally preferred by seismologists to reveal the P- and S-wave velocity structure of the earth. A receiver function is defined as the time series where phases are converted from P to S or from S to P. Teleseismic P waveform contains Ps phases composed of the converted and multiplied phases created from discontinuities under the seismic station. In this study, we aim to explore the upper-lower crust structures beneath two short-period seismic stations ARPR and MALT, in SE Türkiye. For this purpose, two different geophysical techniques are used and their results are compared with each other for better understanding of geological structures and discontinuities under these stations. Firstly, we performed the inversion of P-Receiver Functions using the iterative algorithm, similar to the simulated annealing method. In order to obtain the stacked P-Receiver Functions, the process involves three fundamental steps composed of rotation, deconvolution and stacking. Secondly, we used phase-weighted slant stacking to determine the Ps converted and multiple phases. In this algorithm, the stacked processing of all receiver functions is performed to the slowness values of each signal with the arrival time. According to our results, Moho depth varies from ~37 km beneath the MALT station with Vs=4.3 km/s to ~39 km under the ARPR station Vs=4.2 km/s, besides Conrad discontinuity appeared in the depth of ~18 km around the short-period seismic stations. On the other hand, the high Vp/Vs ratio of the upper and lower crust (~1.90) should be interpreted as the mafic crustal composition, the presence of partial melting and high heat low flow. Finally, the findings revealed from these two stack algorithms are generally consistent with both each other and other studies performed in the region in recent years. As a remarkable fact, the calculated P- and S-wave velocity values with the depths of discontinuity such as Moho and Conrad will contribute to the accurate earth model design, the analyzing of the focal mechanism solutions of earthquakes and the future seismic hazard evaluation in the region.