RISE project

Using a deep sea submersible (ALVIN) to search for hydrothermal activity at depths around 2600 meters, the project discovered a series of vents emitting dark mineral particles at extremely high temperatures which gave rise to the popular name, "black smokers".

[1] The study area at 21° N was selected following results from a series of detailed near-bottom geophysical surveys that were designed to map the geologic features associated with a known spreading center.

[4][5] The project objective was detecting and mapping the sub-seafloor magma chamber that feeds lavas and igneous intrusions that create the oceanic crust and lithosphere in the process of seafloor spreading.

[8] The major experiment effort though, was seafloor observation and sample collection using the deep submergence submersible ALVIN on the crest of the EPR at depths of 2600 meters or more.

[1] RISE was part of the RITA (Rivera-Tamayo expeditions) project, which included submersible investigations (CYAMEX) at 21° N and at the Tamayo Fracture zone at the mouth of the Gulf of California.

[1] These were anticipated by the discovery during the CYAMEX expedition a year earlier of massive sulfide mineral deposits on the sea floor at 21°N, which were presumed to be due to hydrothermal activity, but which was not then observed.

Further, the significance of discovering at the Galapagos site and 21°N of a chemosynthetic ecosystem that was not dependent on sunlight, existed at high pressures, and was based on chemicals emitted via volcanism, provided a model for how life could have originated on Earth.