Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Meteor	M113-1	28.12.2014 - 22.01.2015		North Atlantic Ocean

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Hubscher Christian	Institut fur Geophysik der Universitat Hamburg	Ponta Delgada	Ponta Delgada

Ziel der Reise / Objectives of Cruise:

Oceanic plateaus are large areas of anomalously thick crust forming large bathymetric swells in the ocean basins and their petrological formation and subsequent sedimentological evolution is only poorly understood. The reason for the magmatic and volcanic activity that built the igneous part of the Azores Plateau is debated. As in other places of the world deep, hot mantle plumes are believed to cause the magmatism due to their high excess temperature. According to an alternative model volcanism is explained by excess melting of the mantle due to an elevated volatile content. In addition, the structural evolution of the plateau and the relationship between rifting and volcanism is a matter of active scientific debate. It is suggested that an oblique spreading axis jumped incrementally from the East Azores Fracture Zone towards the north-east. The Terceira rift axis along the northern border of the Plateau represents the present stage and the recent plate boundary between the Eurasian and African plates. In addition, recurrence rate, trigger mechanisms, volumes, and transport processes of large scale mass wasting events are amongst the scientific questions targeted. R/V Meteor expedition M113 aimed at the geophysical, geochemical and petrological evolution of both the deeper, older sites on the plateau and the younger eruption sites in the vicinity of the Terceira axis. The geophysical program (multi-beam, parametric sediment echosounding and reflection seismics) was designed to test the following hypotheses: ? Explosive volcanism is the prevailing eruption mechanism in the submarine Azores volcanic cones. ? Volcanic cone evolution is independent of water depth. ? Locations of submarine volcanoes are related to shallow tectonic faults reflecting the plate-tectonic evolution of the Azores Plateau. ? Hydrothermal activity is associated with volcanic cones. Rock sampling was carried out at few older and several young submarine volcanic eruption sites which have not been studied in detail yet. The following working hypotheses will be tested by petrological and geochemical analysis of the recovered samples: ? Explosive submarine volcanism is primarily caused by abundant volatile compounds and not by magma-water interaction. ? Volcanism becomes younger west of the respective islands implying that most islands move away from their sources of melting. ? The 1998 Terceira eruption formed submarine lava fountains. ? Eruptions near the Jo?o de Castro seamount occur dominantly in the main volcanic edifice but also occur in the two rift zones N and NE of the volcanic system. Multi-beam and seismic data will provide the crucial site-survey data for ROV sampling during a forth-coming research cruise and the tectono-volcanic structural framework for the interpretation of the samples. The micro- and nano-plastic concentration within the surface water will be measured by geochemical analyses of water sampled during the cruise. The multichannel seismic equipment comprised four seismic sources and a 600 m long digital streamer. The set of hydro-acoustic systems includes the hull mounted EM122 multi-beam and parametric sediment subbottom profiler system Parasound. Rock sampling was carried out by means of a wax corer and a TV-grabber. All together, we collected 89 multi-channel seismic profiles with a summed length of 3500 km. TV-grabber and wax corer was used at 29 stations. Hydroacoustic data were collected along the entire ship track (5700 km).

Messungen / Measurements