These data are freely available under the Creative Commons Attribution 4.0 International Licence (CC BY 4.0) When using the data please cite: Bentz, S.; Kwiatek, G.; Durand, V.; Wollin, C.; Bohnhoff, M.; Martínez-Garzòn, P. (2020): Earthquake catalog derived from Template Matching related to "A two-scale preparation phase preceded a Mw 5.8 Earthquake in the Sea of Marmara offshore Istanbul, Turkey". GFZ Data Services. https://doi.org/10.5880/GFZ.4.2.2020.006 The data are supplementary material to: Durand, V., Bentz, S., Kwiatek, G., Dresen, G., Wollin, C., Heidbach, O., Martínez-Garzòn, P., Cotton, F., Nurlu, M., & Bohnhoff, M. (2020). A Two-Scale Preparation Phase Preceded an Mw 5.8 Earthquake in the Sea of Marmara Offshore Istanbul, Turkey. Seismological Research Letters. https://doi.org/10.1785/0220200110 The dataset presented here is an earthquake catalog for the Central Sea of Marmara (Turkey) obtained by applying a matched-fliter technic to continuous waveforms. The magnitude of completeness of this catalog is Mc=1.1. We use as templates events published by national agencies (KOERI and AFAD). The matched-fliter technic is described in Bentz et al. (2019). The column of the data file are described below. The ZIP files contains configuration files for ph2dt and HypoDD applications together with input phase and seismic network data. Column descripion of data table: Template_Matching_catalog_CentralMarmaraSea_2019.txt: Columns in the file: ID (integer) Event ID number YYYYMMDDHHMMSS. YEAR (integer) MONTH (integer) DAY (integer) HOUR (integer) MINUTE (integer) SECOND (float) SERIAL TIME (float) refers to matlab serial time, i.e. the number of days from January 0, 0000, fractions of days are given as decimal digits LATITUDE (float) in decimal degrees LONGITUDE (float) in decimal degrees DEPTH (float) in km MAGNITUDE (float) magnitude derived from the template events magnitudes (see the Methods section of the related paper for details) CROSS-CORRELATION COEFFICIENT (float) averaged cross-correlation coefficient on all the used stations for a detected event TEMPLATE ID (integer) ID number (YYYYMMDDHHMMSS) of the template used for the detected event. MAD (float) ratio between the cross-correlation coefficient and the median absolute deviation of daily correlogram. QUALITY FLAG (character) A: event located using HypoDD, B: event located using Equal Differential Time surface (EDT), C: location from the regional catalogs.