Upper crustal velocity structure of Santorini volcano and the surrounding region, Hellenic volcanic arc (Heath et al., 2019)

This data set consists of a 3-D tomographic model of the P-wave seismic velocity structure of the upper 4 km of the crust of Santorini caldera and the surrounding region. The model was derived from active-source data acquired during the PROTEUS 3-D seismic tomography experiment conducted during Langseth cruise MGL1521 in 2015 (chief scientists Emilie Hooft, Doug Toomey, & Paraskevi Nomikou). The model and results are described in Heath et al. (2019). The data was collected using a dense amphibious array of >14,300 marine sound sources from a 6,600 cubic inch 36-component air gun array towed at 12-m depth that were recorded on 156 short-period marine and land seismometers, covering an area 120 km by 45 km. Average shot spacing was ~150 m along ENE-WSW oriented shot lines spaced at 1–2-km intervals and included shot-receiver offsets up to ~115 km. A three-dimensional, iterative tomographic technique (Toomey et al., 1994) was used to invert over 200,000 Pg refraction arrival times to constrain isotropic slowness within the upper crust. The data file is in SEG-Y format with UTM coordinates (zone 35N) and with P-wave velocity on a grid that is spaced 200 m horizontally and 50 m vertically. This model is NOT masked in regions of poor ray coverage and poor resolution. This data set was generated as part of the project called Collaborative research: Crustal magma plumbing of the Santorini volcanic system. Funding was provided by NSF grants OCE14-59794.