Deep Fault Drilling Project DFDP-1 and -2 – Operational data sets

New Zealand’s Alpine Fault is a site of global importance for the study of active geological faults. The Alpine Fault provides an opportunity to study a major fault late in the cycle of stress accumulation ahead of a future earthquake, to search for precursors to large earthquakes, and to understand the long-term evolution of faults and the formation of fault rocks. The fault’s self-exhuming geometry, relative geological simplicity, and rapid and precisely-known slip rates, mean its accessible surface exposures have already been the subject of >40 years of intensive research. The goal of the Alpine Fault, Deep Fault Drilling Project (DFDP) is to go beneath the surface, to sample and make observations of the fault rocks and physical conditions at a range of depths, and monitor these over coming decades. To date, no active fault drilling experiment has targeted the mid-crustal roots of a long-lived active fault, or addressed fault zone evolution throughout the seismogenic zone and towards the brittle-ductile transition. The DFDP-1 pilot drilling has been completed in February 2011 (Sutherland, 2013). The boreholes DFDP-1A to 100.6 m and DFDP-1B to 151.4 m have been cored and instrumented. DFDP-2A drilling started in August 2014 and DFDP-2B was completed in January 2015, having reached a maximum depth of 893 m (Sutherland, 2015; Toy, 2017). This data publication includes the field inventory and data sets of the DFDP-1 and 2 drillings.