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

CSV catalog file and visualizations of NLL-SSST-coherence earthquake relocations for the 2023 Mw 7.8 and Mw 7.6, Kahramanmaraş - Gaziantep, Turkey earthquake sequence (28,264 events, M≥1.5, 2023-01-01 to 2023-06-24).

NLL-SSST-coherence (Lomax and Savvaidis, 2022; Lomax and Henry, 2023) is an enhanced, absolute-timing earthquake location procedure which 1) iteratively generates spatially varying travel-time corrections to improve multi-scale location precision and 2) uses waveform similarity to improve fine-scale location precision.

Relocations performed with merged phase arrival data available from AFAD (https://deprem.afad.gov.tr/event-catalog) and KOERI (http://www.koeri.boun.edu.tr/sismo/2/bultenler) downloaded on 2023-06-23. All events in the AFAD catalog with M≥1.5 are used for relocation; for each AFAD event, arrival data for the corresponding events from KOERI is merged when available (epicenter within 10km, origin time within 10 sec).

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.

[For relocations of events starting from 2020-01-01 through 2023-03-04 and including the 2020 Mw 6.8 Elazığ, Turkey sequence, see v1.0 of this dataset: https://doi.org/10.5281/zenodo.7699882]

This repository archive file contains:

Full catalog in CSV format:  X_Turkey_20230624A_Acarel2019smooth_NLL-SSST-coherence_M1.5.csv
CSV file data columns correspond to selected fields of the of NonLinLoc Hypocenter format output http://alomax.free.fr/nlloc/soft7.00/formats.html#_location_hypphs_

Key NLL-SSST-coherence configuration files: NLL-SSST-coherence_config/

Visualization images:

    Full catalog:  A_Turkey_20230624A_Acarel2019smooth_NLL-SSST-coherence_M1.5.png
    Events with (68% location ellipsoid) err ≤ 8km, origin-time color scale:  B_Turkey_20230624A_Acarel2019smooth_NLL-SSST-coherence_M1.5_se8km_OTIME.png
    Events with err ≤ 8km:  B_Turkey_20230624A_Acarel2019smooth_NLL-SSST-coherence_M1.5_se8km.png
    Events with err ≤ 8km, depth ≤ 10km:  C_Turkey_20230624A_Acarel2019smooth_NLL-SSST-coherence_M1.5_se8km_z-10.png
    Events with err ≤ 8km, depth ≥ 10km:  C_Turkey_20230624A_Acarel2019smooth_NLL-SSST-coherence_M1.5_se8km_z10-.png

Symbol size is proportional to event magnitude.
AFAD stations shown by light gray inverted pyramids.
KOERI stations shown by dark gray inverted pyramids.

Origin-time plot event colors:
Blue: before 2023-02-06 M 7.8 event
Yellow: from 2023-02-06  01h17 UTC M 7.8 event through 2023-02-06 10h24 UTC M 7.6 event
Orange to Red: after 2023-02-06 10h24 UTC M 7.6 event

Plot data:
Background image from https://opentopography.org
Mapped surface faults (light purple) from: Emre, Ö., Duman, T.Y., Özalp, S., Şaroğlu, F., Olgun, Ş., Elmacı, H. & Çan, T., 2018. Active fault database of Turkey. Bull Earthquake Eng, 16, 3229–3275. https://doi.org/10.1007/s10518-016-0041-2
Surface Rupture Lines (green) from: Reitman, N.G., Briggs, R.W., Barnhart, W.D., Thompson Jobe, J.A., DuRoss, C.B., Hatem, A.E., Gold, R.D., Akçiz, S., Koehler, R.D., Mejstrik, J.D., Collett, C., 2023, Fault rupture mapping of the 6 February 2023 Kahramanmaraş, Türkiye, earthquake sequence from satellite data: U.S. Geological Survey data release, https://doi.org/10.5066/P985I7U2.

Thanks to Sinan Ozeren, Didem Cambaz, Fatih Turhan, Dogan Kalafat, Selda Altuncu Poyraz, Kıvanç Kekovalı, Onur Tan, Alberto Michelini and Pierre Henry for assistance and discussions.