Precise, NLL-SSST-coherence hypocenter catalog for the 2023 Mw 7.8 and Mw 7.6 SE Turkey earthquake sequence.

CSV catalog and plot of preliminary NLL-SSST-coherence earthquake relocations of 26,602 events 2020-01-01 to 2023-03-04 for the 2023 Mw 7.8 and Mw 7.6, Kahramanmaraş - Gaziantep, Turkey earthquake sequence (includes the 2020 Mw 6.8 Elazığ, Turkey sequence). NLL-SSST-coherence (Lomax and Savvaidis, 2022) is an enhanced, absolute-timing earthquake location procedure which 1) iteratively generates spatially varying travel-time corrections to improve multi-scale precision and 2) uses waveform similarity to improve fine-scale precision. Preliminary relocations performed with phase arrival data available from AFAD on 2023-03-04. Higher precision NLL-SSST-coherence relocations should be available when reviewed, merged, seismic phase arrival data is available from AFAD, KOERI (https://eqe.boun.edu.tr) and other networks. Seismic velocity model is a smoothed version of the "Final 1-D" velocity model from: Acarel, D., Cambaz, M.D., Turhan, F., Mutlu, A.K. & Polat, R., 2019. Seismotectonics of Malatya Fault, Eastern Turkey. Open Geosciences, 11, 1098–1111. Available at: https://doi.org/10.1515/geo-2019-0085. CSV data columns correspond to selected fields of the of NonLinLoc Hypocenter format output http://alomax.free.fr/nlloc/soft7.00/formats.html#_location_hypphs_ Plot shows: Subset of NLL-SSST-coherence earthquake relocations 2020.01.01 to 2023-03-04 with ellipsoid semi-major axis (NLL EllipsoidLen3) ≤ 9km (16,762 events). Symbol size is proportional to event magnitude. Used AFAD stations shown by inverted pyramids. Plot event colors: Cyan: before 2023-01-01; includes the 2020 Mw 6.8 Elazığ, Turkey sequence Green-Yellow: before 2023-02-06 M 7.8 event Red: from 2023-02-06 01h17 UTC M 7.8 event through 2023-02-06 10h24 UTC M 7.6 event Magenta: after 2023-02-06 10h24 UTC M 7.6 event Plot data: Background image from https://opentopography.org/ (approximate projection). Simplified faults (blue) from USGS "Turkey Earthquake Emergency Response" map: https://usgs.maps.arcgis.com/apps/webappviewer/index.html?id=5229bb842bd64b688d769abbefe43b46DATA AND RESOURCES: Earthquake relocations performed using seismic phase arrival picks and station metadata available from: Republic of Turkey, Ministry of Interior, Disaster and Emergency Management Presidency, Earthquake Department (AFAD) https://deprem.afad.gov.tr/event-catalog. NLL-SSST-coherence earthquake relocations done with NonLinLoc (http://www.alomax.net/nlloc, https://github.com/alomax/NonLinLoc) configured for NLL-SSST-coherence (https://doi.org/10.5281/zenodo.4756709, Lomax and Savvaidis, 2022). SeismicityViewer (http:// www.alomax.net/software) was used for 3D seismicity analysis and plotting. Waveforms for the following channels and networks were obtained through the specified FDSN data centers: TU_ANDN_--_HHZ : https://doi.org/10.7914/SN/TU http://www.orfeus-eu.org ; GE_ARPR_--_SHZ,GE_ARPR_--_BHZ : https://doi.org/10.14470/TR560404 https://geofon.gfz-potsdam.de ; KO_GAZ_--_HHZ,KO_BNN_--_HHZ : https://doi.org/10.7914/SN/KO http://service.iris.edu ; The facilities of IRIS Data Services, and specifically the IRIS Data Management Center, were used for access to waveforms and related metadata used in this study. IRIS Data Services are funded through the Seismological Facilities for the Advancement of Geoscience and EarthScope (SAGE) Proposal of the National Science Foundation under Cooperative Agreement EAR-1261681