DOI: 10.17603/ds2-7ry2-gv66
title: StEER: 2023 Mw 7.8 Kahramanmaras, Türkiye Earthquake Sequence Preliminary Virtual Reconnaissance Report (PVRR)
title: in StEER- February 6, 2023, Kahramanmaras, Türkiye, Mw 7.8 Earthquake

description: An Mw 7.8 earthquake occurred at a depth of 17.9 km and with epicenter coordinates 37.174°N 37.032°E near the city of Nurdağı in the Gaziantep province of Türkiye at about 4:17 AM local time on February 6, 2023. As a result of this sequence of earthquakes and aftershocks, around 28,500 buildings partially or completely collapsed, while another 66,000 buildings were severely damaged in Türkiye. In Syria, more than 22,000 buildings were affected by the earthquakes, with 2,850 partially/completely collapsed or severely damaged. As of March 8, the total official death toll due to these earthquakes was reported to be 45,968 confirmed deaths in Türkiye and 7,259 in Syria. In Türkiye alone, more than 100,000 people were reported as injured. The province of Hatay in Türkiye was severely impacted by this sequence of ground shaking, including an Mw 6.4 earthquake that occurred on February 20, two weeks after the main event. Around half of the buildings in the affected regions of Türkiye were constructed before 2000, i.e., before modern principles of earthquake design were implemented in the Turkish Seismic Code. Fragility functions developed for the building stock in the area showed that collapse under large shaking was possible for these relatively older buildings. However, several collapses of buildings constructed after 2000 were also observed. The performance of infrastructures was generally acceptable, with most bridges, roads, and tunnels remaining operational and no significant issues with the power grid and water supply infrastructure.  
In terms of good performance, the 12 seismically isolated hospitals in the earthquake-impacted region were operational after the earthquakes and, more importantly, allowed these healthcare facilities to serve their emergency response functions in the aftermath of the extraordinary destruction. Their operational performance greatly contrasted with the observed collapses of some hospitals that were not seismically isolated.
This project encompasses the joint products of the StEER and EERI LFE program's response to this event: Preliminary Virtual Reconnaissance Report (PVRR). The PVRR includes both the official report as well as a supplementary media repository containing additional imagery gathered by the VAST, and a spreadsheet summarizong the metadata of geolocated images contained in the Media Repository.
description: This joint Preliminary Virtual Reconnaissance Report (PVRR) issued by the Structural Extreme Events Reconnaissance (StEER) network and Earthquake Engineering Research Institute (EERI) Learning From Earthquakes (LFE) Program: 1) provides details of the February 6 Mw 7.8 and Mw 7.5 earthquakes, 2) describes local seismic codes and building construction practices, 3) compares the recorded ground shaking with the parameters used for design, 4) summarizes the preliminary reports of damage to buildings and other infrastructure, including the disruption to the community in terms of fatalities, downtime, and economic losses, and 5) highlights key lessons learned, with recommendations to inform the continued study of this event by the engineering community. Due to the magnitude and impact of the earthquake, specialists across the globe participated in the production of this report.