Fault Rupture Mapping of the 6 February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence from Satellite Data (ver. 1.1, February 2024)

This data release contains two datasets that depict fault rupture on the East Anatolian and Çardak faults resulting from the Mw7.8 and Mw7.5 earthquakes in Turkey (Türkiye). It contains two additional datasets that describe satellite imagery coverage and observation gaps. The 6 February 2023 earthquake sequence caused >500 km of combined surface rupture on the primarily left-lateral strike-slip East Anatolian and Çardak faults. The two datasets represent (1) simplified fault traces inferred from displacement discontinuities in interferometric synthetic aperture radar (InSAR) scenes mapped at 1:750,000 scale (“simple_faults”) and (2) detailed mapping of fault surface rupture observed on high-resolution (<1.0 m/pix) optical images from the WorldView 1, 2, and 3 (© 2023 Maxar) satellites mapped at 1:1,500 scale (“surface_rupture_lines”). The mapping is based on satellite data and has been ground checked in select locations. These datasets were mapped primarily from February 6 to 17, 2023, with minor updates and quality control thereafter. They have undergone full peer review but remain subject to revision as more information becomes available. Datasets are provided in shapefile, KML, and geoJSON formats.

Updates to version 1.1: A minor update, version 1.1 contains new “simple_fault” and “surface_rupture lines” files. The “simple_fault” linework has been updated to include the correct orientation of the northern Narlı fault, checked on WorldView images and on the ground. The “surface_rupture_lines” linework has been updated with minor additional fault traces that were overlooked in v1.0 and updated locations of some surface rupture lines to agree with on-the-ground reconnaissance.

Disclaimer: "Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government."
 
Explanation of Data:
Surface Rupture Lines
Detailed mapping of fault surface rupture visible on WorldView 1, 2, and 3 (© 2023 Maxar) images collected after the earthquakes with 0.3-1.0 m pixel resolution. WorldView images with poor georeferencing were georeferenced to pre-earthquake Microsoft Bing imagery on the south or southwest side of the fault. Due to the large offset magnitude and variable accuracy of georectified satellite images, rupture traces are commonly within 15 m, but may be up to 100 m, from their true location on the ground. The mapping has been reviewed for positional accuracy relative to WorldView images and confidence of tectonic origin. Lines included in this dataset are believed by the authors to result from fault surface rupture. Surface deformation believed to be related to liquefaction, lateral spread, or landslides is not included in this dataset. This dataset was mapped at 1:1,500 scale. Rupture trace mapping is incomplete because Maxar images are not available for the entire rupture area at the time of publication; the ground surface is obscured by clouds, snow, or forest; and several images have large off-nadir angles that cause image distortion. The “earthquake” field denotes if the feature is related to the Mw7.8 or Mw7.5 earthquake.
 
Simple Faults
Simplified mapping of fault traces observed from displacement discontinuities in InSAR scenes. Mapping was performed at 1:750,000 scale from Sentinel-1 range and azimuth displacements obtained from pixel correlation with ~30 m pixel resolution (Copernicus Open Access Hub, 2023). The mapped fault traces are inferred from InSAR data and not directly observed. These simplified fault traces were adjusted to be co-located with the detailed surface rupture mapping. The “earthquake” field denotes if the feature is related to the Mw7.8 or Mw7.5 earthquake. The InSAR sub-pixel offsets are available in a USGS data release (Goldberg et al., 2023). The file is called “SAR sub-pixel offsets of February 2023 Kahramanmaras, Türkiye, Earthquake Sequence”.
 
Imagery Coverage
This dataset shows post-earthquake WorldView (© 2023 Maxar) image coverage used for detailed surface rupture mapping. The “fileName” and "prodDesc" fields describe which WorldView images were used for mapping at that location. Images were collected between 6 February and 30 March 2023.
 
Observation Gaps
This dataset uses lines to depict why gaps (≥1 km) in the detailed surface rupture mapping exist. Gaps in detailed surface rupture mapping are described in the “reason” field. Flags are: “no image” where WorldView (© 2023 Maxar) imagery was not available; “cloudy” where images exist but the ground surface is obscured by clouds; “water” where the surface rupture crosses a body of water; or “rupture not observed” where images exist and the ground surface is visible, but surface rupture was not observed. “Rupture not observed” observation gaps may be due to ground cover (e.g., forest, snow) or gaps in the surface expression of fault rupture.
 
References
Copernicus Open Access Hub, 2023, Copernicus Sentinel-1 data. Retrieved from Copernicus SciHub and ASF DAAC February 2023, processed by ESA. https://scihub.copernicus.eu/
 
Goldberg, Tuncay Taymaz, William L. Yeck, William D. Barnhart, Seda Yolsal-Çevikbilen, Tahir Serkan Irmak, Taylan Öcalan, Berkan Özkan, Ceyhun Erman, Ali Hasan Doan, and Cemali Altunta, 2023, Supporting data and models for characterizing the February 2023 Kahramanmaras, Türkiye, earthquake sequence: U.S. Geological Survey data release, https://doi.org/10.5066/P9R6DSVZ
 
Maxar, 2023, Worldview 1, 2, and 3 data. Retrieved between 6 February and 1 May 2023.