Maulidina, Miftakhul (2015) Analisa Struktur Bawah Permukaan Tanah Di Sekitar Candi Gambar Wetan, Kabupaten Blitar Dengan Metode Very Low Frequency Electromagnetic (VLF-EM). Masters thesis, Institut Teknologi Sepuluh Nopember.
Preview |
Text
1113201201-Master_theses.pdf - Published Version Download (2MB) | Preview |
Preview |
Text
1113201201-Presentation.pdf - Published Version Download (2MB) | Preview |
Abstract
Penelitian struktur bawah permukaan tanah di sekitar Candi Gambar Wetan yang bertempat di Desa Sumberasri, Kecamatan Nglegok, Kabupaten Blitar bertujuan untuk mengetahui anomali dan menentukan sebaran batuan bawah permukaan sekitar candi. Metode yang digunakan adalah metode
Very Low Frequency Electromagnetic (VLF -EM). Pengambilan data di lapangan dilakukan dengan membagi area menjadi beberapa lintasan. Spasi antarlintasan sebesar 1m. Perekaman
data VLF dilakukan di tiap titik pada masing
-masing lintasan dengan spasi antartitik sebesar 0.5 meter . Hasil akusisi atau perekaman data VLF berupa
nilai inphase,quadrature,t-field, dan tilt. Data tersebut diolah menggunakan filtering NA- MEMD untuk menguraikan sinyal berfrekuensi tinggi hingga rendah sehingga dapat menghilangkan noise. Selanjutnya, data tersebut diolah
menggunakan Filter Karous Hjelt untuk interpretasi kualitatif, yaitu menentukan letak anomali yang lebih konduktif dan resesif. Selain itu, data juga diinversi menggunakan software Inv2DVLF-v1 untuk
interpretasi kuantitatif, yaitu melakukan estimasi nilai resistivitas semu berdasarkan data inphase
dan quadrature. Setelah itu, keduanya digabung menjadi
interpretasi keseluruhan. Berdasarkan hasil penelitian yang telah dilakukan pada 9 line, sebagian besar
teridentifikasi anomali resistif yang diduga adalah batuan andesit dengan resistivitas berkisar 120-220 Ωm pada kedalaman 0-40 meter. Hasil penelitian ini diharapkan dapat membantu dalam menemukan arca atau sedimen
-sedimen batuan yang masih terpendam di dalam tanah karena candi induknya hingga saat ini belum ditemukan. ========== A geophysical investigation to study anomalies and determine the distribution of rocks within the
subsurface using the Very Low Frequency Electromagnetic
(VLF -EM) method was conducted around Gambar Wetan
temple. We have measured subsurface structure by dividing the area into several tracks. The spacing of trajectory is 1 meter. The measurement was done at each point on each trajectory with spacing of 0.5 meters. As a result, we get the data of inphase, quadrature, t-f ields, and ti
lt. Noise-Assisted Multivariate Empirical Mode Decomposition (NA-MEMD) was applied to the data to denoise the signal of VLF -EM data. The NA-MEMD filtered data were then interpreted qualitatively using Karous-Hjelt filter to get the location of the anomaly which is more
conductive or more resistive. Quantitative interpretation using Inv2DVLF-v1 for the inversion of tipper data (inphase and quadrature) were also done to get the apparent resistivity profile. Then, both were combined to get the overall interpretation. The results showed that there are generally two anomalies detected around the temple in 9 lines measurement, conductive and resistive anomaly. The
resistive anomaly predicted as andesit has a resistivity 120
-200 Ωm at depth of 0-40 meters. This is expected to help in finding rocks within the subsurface because the main temple has not been found.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | VLF -EM; sedimen batuan; NA-MEMD; Filter Karous Hjelt; inversi; rock sediment; inversion. |
| Subjects: | Q Science > QE Geology > QE471 Sedimentary rocks. Sedimentology S Agriculture > S Agriculture (General) > S593.2 Soil Structure |
| Divisions: | Faculty of Mathematics and Science > Physics > 45101-(S2) Master Thesis |
| Depositing User: | - Davi Wah |
| Date Deposited: | 15 May 2018 04:34 |
| Last Modified: | 15 May 2018 04:34 |
| URI: | http://repository.its.ac.id/id/eprint/51745 |
Actions (login required)
 |
View Item |