Compilation of a Comprehensive Earthquake Catalog and Relocations in the Caucasus Region

Journal Article · Wed Jan 03 00:00:00 EST 2024 · Seismological Research Letters

DOI:https://doi.org/10.1785/0220230206· OSTI ID:2315094

Godoladze, Tea ^[1]; Gök, Rengin  ^[2]; Onur, Tuna ^[3]; Gunia, Irakli ^[1]; Dzmanashvili, Manana ^[1]; Boichenko, Giorgi ^[1]; Buzaladze, Albert ^[1]; Bondár, István  ^[4]; Ratiani, Lana ^[1]; Rostomashvili, Tinatin ^[1]; Nabelek, John  ^[5]; Javakhishvili, Zurab ^[1]; Yetirmishli, Gurban  ^[6]; Sandvol, Eric  ^[7]; Kadirioğlu, Filiz Tuba  ^[8]; Chiang, Andrea  ^[2]

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1. Ilia State University, Tbilisi (Georgia)
2. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
3. Onur Seemann Consulting, Inc., Victoria, British Columbia (Canada)
4. Eötvös Loránd Research Network (ELKH), Budapest (Hungary)
5. Oregon State University, Corvallis, OR (United States)
6. Republic Seismic Survey Center of ANAS, Baku (Azerbaijan)
7. University of Missouri, Columbia, MO (United States)
8. Disaster and Emergency Management Authority (AFAD) (Turkey)

Instrumental seismic monitoring has a long history in the Caucasus and started in 1899 when the first seismograph was installed in Tbilisi, Georgia. Much of the analog paper records from this time period are preserved in the Tbilisi archives because Georgia served as the regional data center. In the 1990s, due to the collapse of the Soviet Union and the political turmoil in the region, the analog networks and the communication between the newly formed national networks deteriorated. In Georgia, for the next 13 yr, the seismic network coverage was poor until the 2002 Tbilisi earthquake. Following this earthquake, the first permanent digital seismic station in Georgia was established in Tbilisi in 2003. The digital era progressively improved the ability to collect and archive data and today more than a hundred broadband seismic stations (including temporary arrays) are operating in the southern Caucasus. Until recently, the region lacked a coordinated effort to catalog all analog and digital era data collected by different countries into a single repository. As a result of collaboration between Lawrence Livermore National Laboratory, the Ilia State University, and the Republican Seismic Survey Center of Azerbaijan, a comprehensive earthquake catalog was compiled for the Caucasus and neighboring areas as part of a broader probabilistic seismic hazard assessment project. Here this project digitized Soviet-era paper bulletins, compiled a unified earthquake catalog from regional bulletins, developed 1D reference velocity model, and used it to relocate the events. The final catalog contains 16,963 events with magnitudes 3.7 and above, bringing together all the available data sets in the Caucasus region from 1900 to 2015, significantly improving locations, and generating the most complete earthquake catalog in the region, temporally and geographically.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); Georgian National Foundation
• Grant/Contract Number: AC52-07NA27344; NFR17-454
• OSTI ID: 2315094
• Report Number(s): LLNL-JRNL-846667; 1070647
• Journal Information: Seismological Research Letters, Vol. 95, Issue 2A; ISSN 0895-0695
• Publisher: Seismological Society of America
• Country of Publication: United States
• Language: English

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