Distribution and chronology of submarine volcanic rocks around Santorini and their relationship to faulting

Abstract

Seismic reflection profiles from the marine areas around Santorini in the south Aegean arc show the distribution of active faults and the occurrence of submarine volcanic rocks interfingering with stratified basinal sediment. Santorini is located at the intersection of fault sets of different ages. To the west, active faults trend east-west, whereas to the east, active faults trend ENE-WSW and a slightly older set of faults trends NE-SW. Subsurface submarine volcanic rocks can be dated using ages estimated for the stratified basin sediments elsewhere in the Milos-Christiani Basin. Volcanic horizons off Santorini correlate with the main (young) Akrotiri (0.65-0.55 Ma) and old Akrotiri (1.6 ka) volcanic episodes, respectively. Off Christiani, the upper unit of volcanic rocks is of similar age to the young Akrotiri episode and the lower volcanic unit is likely to be of latest Pliocene age. Late Neogene basin subsidence and volcanism are a consequence of changing patterns of faulting resulting from the collision of the African and Aegean-Anatolian plates.

Seismicity and active tectonics at Coloumbo Reef (Aegean Sea, Greece): Monitoring an active volcano at Santorini Volcanic Center using a temporary seismic network

“…Fracture Zone" (Perissoratis, 1995;Mountrakis et al, 1996;Perissoratis and Papadopoulos, 1999;Pavlides and Valkaniotis, 2003;Piper and Perissoratis, 2003;Piper et al, 2004). This tectonic line lies in an en echelon pattern and is probably part of the Santorini -Amorgos Fault Zone.…”

“…Especially in the Santorini region changes in faulting pattern during Early Pleistocene may be related to the initiation of volcanism (Piper and Perissoratis, 2003;Piper et al, 2004). NE-trending strike-slip faulting that initiated in the latest Pliocene or early Quaternary triggered the Akrotiri volcanic center directly on Santorini Island.…”

“…NE-trending strike-slip faulting that initiated in the latest Pliocene or early Quaternary triggered the Akrotiri volcanic center directly on Santorini Island. These faults then acted as pathways for magma, when strong NE -SW trending faulting began in the mid-Quaternary resulting in the formation of Anydros Basin, Amorgos Basin and the Santorini -Amorgos Ridge (Perissoratis, 1995;Piper and Perissoratis, 2003;Piper et al, 2004) Shirokova, 1972;Comninakis and Papazachos, 1986;Ambraseys and Jackson, 1990;Papazachos et al, 2001;Papazachos and Papazachou, 2002) generating a tsunami of up to 20 m wave heights (Papadopoulos and Pavlides, 1992;Perissoratis and Papadopoulos, 1999). Another important feature in the same area is the Coloumbo Reef (grey star in Figure 2), a submarine volcano 7 km northeast of Santorini Island which has a well defined 1500-meter-wide crater, a crater rim as shallow as 17 m and a crater floor ~500 m below the sea level (Perissoratis, 1995;Francalanci et al, 2005;Sigurdsson et al, 2006).…”

Tectonism and Its Relation to Magmatism Around Santorini Volcano From Upper Crustal P Wave Velocity

“…Metamorphosed sediments of the Attico‐Cycladic complex, which were exhumed during Miocene and younger extension (Piper et al, ; Piper & Perissoratis, ; Xypolias et al, ), highlight the role of tectonics in the evolution of the southern Aegean. These exhumed rocks compose most of the regional islands (e.g., Ios, Amorgos; Lister et al, ; Forster & Lister, ), including a portion of SW Santorini itself (Heiken & Mccoy, ).…”

Vertical & horizontal ground deformation of Santorini island deduced by DGPS measurements

“…The parallel tectonic line of Columbo passes through the cinder cones of Mégalo Vouno, Kokkino Vouno, the Cape Columbo tuff ring, and Columbo volcano. It is clear that the existing tectonic fault zones have strongly influenced the emplacement of magma, as well as the development of the whole volcanic field (Piper et al 2004). At present, the volcanic manifestations on Santorini consist of fumaroles and hot springs, mainly located on Nea Kammeni.…”