SUBVENT-1 Cruise, RV Hespérides

Abstract

The objective of the SUBVENT-1 cruise is to investigate the evidence of emissions from fluids detected west of the Canary Islands, in the deep zone of the continental margin, where possible acoustic feathers that could have been identified generated by underwater emissions of fluids. The SUBVENT1-0913 cruise has been carried out along the lower slope of the continental margin of the Canary Islands. This area is characterized by the presence of several recent geological structures. Among these are the distal parts of the volcanoclastics debris deposits originated by volcanic avalanches of the Canary Islands, transported by gravity along the slope and probably related in origin to eruptive episodes. In the southern part, numerous and different reliefs (seamounts, hills or mounds) of volcanic origin occur. The most frequents features display heights between 30 and 300 m and they have constituted one of the main aims of this survey. Moreover, in this sector there are several subparallel linear scarps with similar directions to the slope trend that could be associated with the aforementioned mounds. The acquisition of new geophysical data and samples during this cruise will allow a better understanding of the origin of these mounds and the emission processes that have generated them. On the other hand, the knowledge of the relationships between debris and hemipelagic sediments together with those associated with possible venting processes in the area, will reveal not only the sedimentary evolution of this margin, but also to establish emission episodes generating mounds and to know their growth patterns. Furthermore, it would be possible to evaluate the sedimentation rate in the area and the role played by the Antarctic Bottom Water (AABW) mass on this process