New insights into the Santorini Amorgos Tectonic Zone from Maria S. Merian expedition 132
Christian Berndt 1, Jens Karstens1, Paraskevi Nomikou2, Gareth Crutchley1, Morelia Urlaub1, Tom Kwasnitschka1, Maria Banch Jover1, Bruna Pandolpho1, Megan Campbell1, and Heidrun Kopp1
Affiliations: 1GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel Germany 2National and Kapodistrian University of Athens, Athens, Greece
Presentation type: Talk
Presentation time: Friday 09:00 - 09:15, Room R280
Programme No: 3.4.3
Abstract
The Santorini Amorgos Tectonic Zone has been the setting of some of the most severe natural disasters in southern Europe in historic times. Both explosive volcanic eruptions and earthquakes related to back-arc rifting have caused destructive tsunamis. The enigmatic location of the volcanic arc far behind the subduction zone both controls and is controlled by back-arc rifting. With new geophysical and seafloor imagery data we constrain the geological processes that control the hazard potential of the area. Reflection seismic data show several generations of explosive eruptions of Kolumbo Volcano near the northwestern termination of the Christiana-Santorini-Kolumbo system. In conjunction with bathymetric data they reveal that the volcanoes have been affected by slope movements and erosion during the emplacement of pyroclastic flows. New 3D seismic data document the structural configuration of part of the seismogenic Amorgos fault zone, with sharp single fault scarps at the centre of the fault close to the southern tip of Amorgos, and more diffuse seafloor deformation towards the southwestern terminations. These significant differences along strike might help to explain the vastly different tsunami run-up heights on surrounding Aegean islands reported by eyewitnesses in 1956.