Volcanism in the Azores: A Marine Geophysical Perspective

摘要: In contrast to oceanic islands produced by mantle melting anomalies or “hotspots” lying in mid-plate settings, the central and eastern Azores are distributed on Nubia-Eurasia tectonic plate boundary experience frequent earthquakes. As they lie an extensional trans-tensional environment, volcanism is organised into submarine subaerial ridges oriented perpendicular oblique direction of separation. Much marine geophysical work undertaken study these features flanks has involved seabed mapping with sonars various kinds, beginning GLORIA long-range sidescan sonar deployed late 1970s continuing more recently deeply towed TOBI multibeam bathymetric dedicated expeditions ship transits. These datasets give us a view topographic structure morphologies volcanic comprising them. Sonars also have been used investigate incidence large- small-scale landsliding around islands, as well lava flows originating from land entering sea. The overall picture emerging one landslides, cones, terraces analogous those Hawaii, Canaries other island groups but notable differences. For example, large-scale landslides appear be rarer cones tend steep-sided pointed, not flat-topped cratered some parts Hawaiian Islands. Faults common environment.