This project involves sampling rock, sediment, water, and gas associated with the catastrophic MW 7.8 and MW 7.5 Kahramanmaras earthquake ruptures in Turkey. These samples are critical for addressing how the physical and chemical properties of the near-surface environment influence how earthquake ruptures propagate or stop, and how earthquakes change groundwater migration along faults. Because scientists working on seismically active faults that have not experienced recent earthquakes commonly have to infer whether rocks observed in the field formed and deformed during an earthquake, these new samples will benchmark characteristics that are unique to earthquake deformation. Thus, these samples will inform on-going and future studies of large-magnitude earthquake-generating faults world-wide. The US PIs, including a female STEM researcher, will work closely with Turkish colleagues and expand research, education, and training opportunities by mentoring a Turkish undergraduate from Istanbul Technical University in field work.<br/><br/>This projects centers on the recent MW 7.8 and MW 7.5 Kahramanmaras earthquake sequence and associated surface rupture in Turkey and is an unprecedented and time-sensitive opportunity to sample Earth materials and fluids that directly participated in surface ruptures during these catastrophic events. The PIs will leverage new mapping of both surface ruptures to sample (1) fault rocks, sediments, and soils from discrete scarps and new fault surfaces produced by these earthquake ruptures, (2) fault damage created and deformed during multiple past earthquake cycles that subsequently participated in these ruptures, (3) waters and gases from new bubbling springs along the ruptures and existing thermal springs proximal to these faults, and (4) in situ CO2 flux measurements along the ruptures at all sample locations<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.