2018-2019 USAP Field Season
Rio Grande Rise: New questions on plume dynamics, Atlantic tectonic evolution and an important window to the African large-low-shear-wave-velocity provinces (LLSVP)
Dr. Antonius Adrianus Petrus Koppers
Supporting Stations: RV/IB Nathaniel B. Palmer
The Rio Grande Rise in the South Atlantic Ocean off the coast of Brazil is a volcanic oceanic plateau that formed on, or close to, the Mid-Atlantic Ridge spreading center. The Walvis Ridge, which is now located off Africa, also formed near the Mid-Atlantic Ridge close to the same time. The Rio Grande Rise is about twice the volume of Walvis Ridge, and together they record about 130 million years of intra-plate volcanism and are hypothesized to represent the products of a deep mantle plume. To understand the history of these large volcanic features, this project will sail on a science cruise to the Rio Grande Rise to survey and collect rock samples from 40 seamounts, rift zone valleys, and steep escarpments. These new data will allow a thorough investigation of the formation of the Rio Grande Rise and its relationship to the Walvis Ridge.
Field Season Overview
In the 2018-19 season, the science team will sail on the RV/IB Nathaniel B. Palmer and will have 38 days (including weather days) devoted to science. They will conduct multibeam sonar surveys over 14 seamounts and 26 target sites along relatively steep rift valley shoulders and escarpments; magnetometer and gravimeter surveys between dredge sites, during transits, and during multibeam surveys; and 40 dredges for rock samples. Science cargo will be onloaded in Punta Arenas, Chile, and the vessel will then sail to Montevideo, Uruguay, where the science party will embark. At the end of the cruise, the science team and their cargo will be offloaded at Montevideo. Transit to and from the study area from Montevideo will add nine days of transit time for a total 47 days at sea.
Deploying Team Members