P and S velocity structures of the Santorini–Coloumbo volcanic system (Aegean Sea, Greece) obtained by non-linear inversion of travel times and its tectonic implications

Submarine volcanoes of the Kolumbo volcanic zone NE of Santorini Caldera, Greece

“…One of the most interesting findings is that the highest frequency of seismic activity currently exists beneath Kolumbo submarine volcano and not Santorini (Bohnhoff et al, 2006). New seismic tomography interpretations also suggest that an active magma chamber exists beneath Kolumbo at a depth of 5-6 km and that it may be linked to the nearby island of Santorini (Dimitriadis et al, 2010). Frequent seismic activity also continues northeast of Kolumbo along the rift basin (Fig.…”

“…These reservoirs appear to have different geochemical and mineralogical characteristics, possibly indicating different source regions with magmas derived directly from the mantle for the case of Kolumbo submarine volcano and with significant partial crustal melting in the case of the Santorini caldera (Francalanci et al, 2005). Dimitriadis et al (2010) suggest that a low-velocity zone extends along the northeastern edge of the Santorini Island, parallel to the "Kameni-Kolumbo" fracture zone (NE-SW direction). This zone corresponds to a tectono-volcanic fracture zone, which probably links the volcanic center of Santorini with the submarine volcano at Kolumbo.…”

Stress field around the Coloumbo magma chamber, southern Aegean: Its significance for assessing volcanic and seismic hazard in Santorini

“…A corollary of this problem is the vertical smearing of the resulting tomographic images which needs to be taken into account when interpreting them. However, Dimitriadis et al (2010) point out that smearing also depends on the direction of the tomographic cross-section, with a NW-SE direction exhibiting less pronounced effects. Fig.…”

“…In a recent study, Dimitriadis et al (2010) used local earthquake tomography in order to obtain P-and S-wave velocity images of the Coloumbo magma chamber. The authors used a dataset consisting of 137 local earthquakes with 1600 P-phases and 1521 S-phases recorded at 25 seismic stations.…”

“…Therefore it seems that the depth derived by the Swave tomographic image is more consistent with the geochemical results. Dimitriadis et al, 2010). The orientation of the cross-sections relative to Santorini is shown on the top map.…”