Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves
Estimation of the fast polarization direction of shear seismic waves that deviate from horizontal axis is a valuable approach to investigate the characteristics of the lower crust and uppermost mantle structures. The lattice preferred orientation of crystals, which is generally parallel to the downw...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
University of Tehran
2018-04-01
|
| Series: | Journal of Sciences, Islamic Republic of Iran |
| Subjects: | |
| Online Access: | https://jsciences.ut.ac.ir/article_65020_0ad2914aae81c9dd195a872d83d2f7c1.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849730666788290560 |
|---|---|
| author | K. Latifi A. Sadidkhouy M. R. Ghassemi |
| author_facet | K. Latifi A. Sadidkhouy M. R. Ghassemi |
| author_sort | K. Latifi |
| collection | DOAJ |
| description | Estimation of the fast polarization direction of shear seismic waves that deviate from horizontal axis is a valuable approach to investigate the characteristics of the lower crust and uppermost mantle structures. The lattice preferred orientation of crystals, which is generally parallel to the downward or upward flow of the mantle or crust, is an important reason for the occurrence of fast axis plunge in these structures. We introduce a new method to estimate the plunge and the true percent of anisotropy. To evaluate the accuracy of the method, we applied it to back azimuthal synthetic receiver functions produced by the Raysum code. The output resulted from this new method (including plunge and percent of anisotropy) were compared with inputs of Raysum code, and reveal that there is a very good coherence among the inputs and output values estimated by our method. This method has been applied to anisotropy analysis beneath two different stations of SHGR in Iran and MOX in Germany. The splitting parameters beneath the SHGR station, are estimated to be φ=60±1 degrees and δt=0.54±0.02 sec. The plunge value and percentage of anisotropy in SHGR are estimated to be 45±0.5 degrees and 4 percent, which can correspond to an old flow in a subduction zone within the area. The splitting parameters in the crust beneath the MOX station, are estimated as φ=98±2 degrees and δt=0.38±0.02 sec. The plunge value and percentage of anisotropy in the crust of the MOX are estimated 45±0.2 degrees and 5.5%. |
| format | Article |
| id | doaj-art-a92cea6b9d034eb9925e58b572c4cdd2 |
| institution | DOAJ |
| issn | 1016-1104 2345-6914 |
| language | English |
| publishDate | 2018-04-01 |
| publisher | University of Tehran |
| record_format | Article |
| series | Journal of Sciences, Islamic Republic of Iran |
| spelling | doaj-art-a92cea6b9d034eb9925e58b572c4cdd22025-08-20T03:08:47ZengUniversity of TehranJournal of Sciences, Islamic Republic of Iran1016-11042345-69142018-04-0129214315610.22059/jsciences.2018.6502065020Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear WavesK. Latifi0A. Sadidkhouy1M. R. Ghassemi21Research Institute for Earth Sciences, Geological Survey of Iran (GSI), Tehran, Islamic Republic of Iran2 Deportment of Seismology, Institute of Geophysics, Faculty of Sciences, University of Tehran, Tehran, Islamic Republic of Iran1Research Institute for Earth Sciences, Geological Survey of Iran (GSI), Tehran, Islamic Republic of IranEstimation of the fast polarization direction of shear seismic waves that deviate from horizontal axis is a valuable approach to investigate the characteristics of the lower crust and uppermost mantle structures. The lattice preferred orientation of crystals, which is generally parallel to the downward or upward flow of the mantle or crust, is an important reason for the occurrence of fast axis plunge in these structures. We introduce a new method to estimate the plunge and the true percent of anisotropy. To evaluate the accuracy of the method, we applied it to back azimuthal synthetic receiver functions produced by the Raysum code. The output resulted from this new method (including plunge and percent of anisotropy) were compared with inputs of Raysum code, and reveal that there is a very good coherence among the inputs and output values estimated by our method. This method has been applied to anisotropy analysis beneath two different stations of SHGR in Iran and MOX in Germany. The splitting parameters beneath the SHGR station, are estimated to be φ=60±1 degrees and δt=0.54±0.02 sec. The plunge value and percentage of anisotropy in SHGR are estimated to be 45±0.5 degrees and 4 percent, which can correspond to an old flow in a subduction zone within the area. The splitting parameters in the crust beneath the MOX station, are estimated as φ=98±2 degrees and δt=0.38±0.02 sec. The plunge value and percentage of anisotropy in the crust of the MOX are estimated 45±0.2 degrees and 5.5%.https://jsciences.ut.ac.ir/article_65020_0ad2914aae81c9dd195a872d83d2f7c1.pdfanisotropyfast polarization directionfast axis plunge estimationshear wave splittingreceiver functions |
| spellingShingle | K. Latifi A. Sadidkhouy M. R. Ghassemi Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves Journal of Sciences, Islamic Republic of Iran anisotropy fast polarization direction fast axis plunge estimation shear wave splitting receiver functions |
| title | Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves |
| title_full | Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves |
| title_fullStr | Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves |
| title_full_unstemmed | Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves |
| title_short | Estimation of Plunge Value in Single- or Multi-Layered Anisotropic Media Using Analysis of Fast Polarization Direction of Shear Waves |
| title_sort | estimation of plunge value in single or multi layered anisotropic media using analysis of fast polarization direction of shear waves |
| topic | anisotropy fast polarization direction fast axis plunge estimation shear wave splitting receiver functions |
| url | https://jsciences.ut.ac.ir/article_65020_0ad2914aae81c9dd195a872d83d2f7c1.pdf |
| work_keys_str_mv | AT klatifi estimationofplungevalueinsingleormultilayeredanisotropicmediausinganalysisoffastpolarizationdirectionofshearwaves AT asadidkhouy estimationofplungevalueinsingleormultilayeredanisotropicmediausinganalysisoffastpolarizationdirectionofshearwaves AT mrghassemi estimationofplungevalueinsingleormultilayeredanisotropicmediausinganalysisoffastpolarizationdirectionofshearwaves |