Electronic Theses and Dissertation

Wilayah Pamir yang berada di perbatasan Tajikistan–Kyrgyzstan merupakan zona konvergen kompleks dengan aktivitas seismik tinggi akibat tumbukan antara Lempeng India dan Eurasia. Penelitian ini bertujuan untuk mengkaji jalur patahan aktif di wilayah Pamir melalui analisis distribusi gempa bumi yang direlokasi dengan metode Coupled Velocity Hypocenter. Data gempa diperoleh dari jaringan seismometer 8H dan 9H milik GeoForschungsZentrum (GFZ) yang merekam selama periode September 2016 hingga Maret 2017. Tahapan analisis meliputi picking manual waktu tiba gelombang P dan S menggunakan SeisComP, lokalisasi awal, serta relokasi hiposenter menggunakan perangkat lunak VELEST. Hasil penelitian menunjukkan bahwa relokasi gempa menghasilkan distribusi hiposenter yang lebih presisi dan membentuk pola lineasi sejajar dengan jalur patahan utama berarah barat laut–tenggara (NW–SE). Pola ini mengonfirmasi keberadaan sistem patahan aktif di wilayah Pamir, termasuk Main Pamir Thrust dan Sarez–Karakul Fault. Selain itu, ditemukan indikasi segmen patahan lain yang belum teridentifikasi sebelumnya di Central Pamir, serta temuan patahan baru di Wilayah Cekungan Tarim yang diperkirakan berperan dalam deformasi lokal pada zona transisi antara Pamir dan Tarim Basin. Secara keseluruhan, penelitian ini membuktikan bahwa metode Coupled Velocity Hypocenter mampu meningkatkan akurasi penentuan lokasi gempa, mengungkap pola seismotektonik, serta memberikan bukti keberadaan patahan aktif maupun patahan baru. Hasil penelitian ini diharapkan dapat memperkaya pemahaman mengenai tektonik regional serta menjadi dasar dalam upaya mitigasi bencana gempa bumi di Asia Tengah.
Kata kunci: Pamir, relokasi gempa bumi, Coupled Velocity Hypocenter, patahan aktif, patahan belum teridentifikasi

The Pamir region, located along the Tajikistan–Kyrgyzstan border, represents a complex convergent zone with high seismic activity caused by the collision between the Indian and Eurasian plates. This research aims to examine active fault systems in the Pamir region through the analysis of earthquake distributions relocated using the Coupled Velocity Hypocenter method. The earthquake data were obtained from the 8H and 9H seismic networks operated by GeoForschungsZentrum (GFZ), which recorded during the period of September 2016 to March 2017. The analysis involved manual picking of P- and S-wave arrival times using SeisComP, initial localization, and hypocenter relocation with the VELEST program. The relocation results demonstrate a more precise distribution of hypocenters that form lineations aligned with major northwest–southeast (NW–SE) fault systems. This pattern confirms the presence of active faults in the Pamir, including the Main Pamir Thrust and the Sarez–Karakul Fault. In addition, the analysis reveals indications of other fault segments not previously identified in Central Pamir, as well as the discovery of a new fault within the Tarim Basin. This newly identified fault is considered to play an important role in local deformation within the transition zone between the Pamir and the Tarim Basin. In conclusion, this study shows that the Coupled Velocity Hypocenter method improves the accuracy of earthquake locations, clarifies seismotectonic patterns, and provides new evidence of both active and unidentified faults. These findings contribute to a better understanding of regional tectonics and support earthquake hazard mitigation efforts in Central Asia. Keywords: Pamir, earthquake relocation, Coupled Velocity Hypocenter, active fault, unidentified fault