FS Meteor M115

Cruise summary report

Cruise Info. 
Ship name (ship code)FS Meteor (06M3)
Cruise identifierM115
Cruise period2015-04-01 — 2015-04-28
Port of departureKingston, Jamaica
Port of returnPointe-à-Pitre, Guadeloupe
ObjectivesAbout 57% of the Earth's surface are covered by oceanic crust and new ocean floor is continuously created along the 55.000-60.000 km long mid-ocean ridge (MOR) system. About 25% of the MOR spread at an ultra slow spreading rate of < 20 mm/yr. Most ultra slow spreading ridges occur in areas of the world that are difficult to reach, like the Gakkel Ridge in the Arctic Ocean and the Southwest Indian Ridge in the Indian Ocean. It has long been recognized that crustal accretion at ultra slow spreading rates is fundamentally different from crust generated at faster spreading rates. However, due to the remoteness of ultra slow ridges the formation of crust at these magma-starved centres is yet not well understood. During the CAYSEIS cruise we surveyed lithospheric formation at ultra slow spreading rates at the Mid Cayman Spreading Centre (MCSC) in the Caribbean Sea. The MCSC occurs in a back-arc setting and spreads at a full rate of ~17 mm/yr. Recent efforts detected the deepest ever observed black smoker system in the Cayman Trough. Using refraction and wide-angle seismics and passive local earthquake monitoring we studied the balance between magmatic accreting / tectonic stretching (and hence oceanic core complex formation) and the relationship between faulting and hydrothermal activity at ultra slow spreading rates. In addition, we explored transform margin formation at a unique setting, occurring at the southern terminus of the MCSC. The project CAYSEIS is a joint programme of German, British and US American scientists.
Chief scientistChristine Peirce (University of Durham, Department of Earth Sciences), Ingo Grevemeyer (GEOMAR Helmholtz Centre for Ocean Research, Kiel (East Shore Campus))
Cruise reportFS Meteor M115 cruise report meteor_m115.pdf (0.79 MB) 
Ocean/sea areas 
GeneralCaribbean Sea
Track chartsFS Meteor M115 cruise track — meteor_m115trk.pdf (2.71 MB) 
Geology and geophysics 
Seismic refractionQuantity: number of deployments = 52
Description: Ocean-bottom seismograph (OBS) - active source - using 3-component geophones and a hydrophone as sensors
Gravity measurementsQuantity: activity duration in days = 27
Description: Gravity - using a LaCoste Romberg sea gravity meter (instrument S-040)
Magnetic measurementsQuantity: number of profiles = 6
Description: Magnetics - using a SeaSpy marine magnetometer
Other geological/geophysical measurementsQuantity: number of deployments = 3
Description: Ocean-bottom seismograph (OBS) deployments - passive seismicity data - using 3-component geophones and a hydrophone as sensors