Rio Grande Rise NBP1808 Expedition

The Rio Grande Rise is a largely unstudied large igneous province (LIP) in the South Atlantic with an area similar to Iceland – a true terra incognita. Expedition NBP1808 explores this region during October-November 2018. On this website expect to see everything from scientific information to thoughts about life at sea aboard the research vessel and ice breaker Nathaniel B. Palmer.

“How did the Rio Grande Rise form?” is the main question that we seek to answer. With dredges we collect rock samples of the lava flows that formed the Rio Grande Rise (RGR) structure roughly between 80 and 40 million years ago. Radioisotopic (40Ar/39Ar) dating and geochemical data on these rocks will provide information how the Rio Grande Rise formed in the context of the opening South Atlantic and its relationship to a sister volcanic system on the African plate, the Walvis Ridge. Because the magmas that formed Rio Grande Rise may come from deep in the mantle, our samples provide a rare geochemical window to the state of the core-mantle boundary. In addition, we will use the new data to refine plate motion models of the South American and African tectonic plates. Previous research has been conducted on Walvis Ridge, and it is now the RGR’s turn! We are collecting this data by mapping and dredging 30-40 seamounts, rift zone valleys, and steep escarpments in the Rio Grande Rise, from 28°S and 39°W to 39°S and 20°W. The depths of these features range from about 4 km to 1 km (2.5-0.6 miles).

To read more about the goals of this expedition, see the Scientific Objectives.

Here you can find daily updates and news of our progress. Check back in for new information!
Day 48 - December 5, 2018
We arrived in Montevideo! Well, almost--at the time of writing this, we still need to pilot into port and go through customs. That should happen soon, though. Read more
Day 47 - December 4, 2018
We have finished up packing! We should be arriving in port tomorrow around noon. It’s been a pleasure participating in this cruise with everyone, and I for one cannot wait to see what exciting discoveries will be rooted in the samples and data we collected. Read more
Day 46 - December 3, 2018
We finally reached the EEZ this morning. The multibeam is off and we are not logging anymore. Our shifts are technically done, but it may take some people a bit to fully change their sleep schedule back. Read more
Day 45 - December 2, 2018
The storm really started to pick up today. We had 50 knot winds for a short bit as the front hit us, but it “died” back down to around 40. We’re still heading for the EEZ. Read more
Day 44 - December 1, 2018
We’ve started another ping pong tournament to pass our free time while we finish processing samples and start packing everything away. In a nice bit of parallelism to the beginning of our cruise, there’s another storm brewing as we head back to Montevideo. Read more
Day 43 - November 30, 2018
Today was a busy day! We had our final day of student presentations. Kaya gave a talk about geothermobarometers, or methods to determine the original formation pressures and temperatures of metamorphic and igneous rocks. Read more
Day 42 - November 29, 2018
A bit of somber news…we lost our dredge basket at Tseenkee Escarpment this morning. This is an accepted risk while dredging since these wires can reach very high tensions very quickly, but it’s always stressful when it happens. Read more
Day 41 - November 28, 2018
The Suhail Escarpment dredge came up and gave us a nice mix of basalts, sediment, and corals. We spent the rest of the day transiting to the next dredge site BUT we were treated to the beginning of our student presentations! Read more
Read All News Updates
Read short reports presenting some of the science behind the cruise, as well as blog stories about life on the RVIB Nathaniel B. Palmer. Don’t worry about having to do extra reading—the reports are written with a general audience in mind, and will cover topics mentioned in the Scientific Objectives as well as other basic geology topics.
Science Report 7 - Multibeam and Sub-bottom profiling
On our exploration of the Rio Grande Rise, we aimed to dredge rock samples from seamounts and escarpments on the seafloor. In order to dredge the ocean floor effectively, we need to be able to map what’s down there in detail. The existing maps of the ocean floor are based on satellite bathymetry. Read more
Science Report 6 - An Intro to Satellite Altimetry
An important aspect of our cruise has been collecting multibeam sonar data to map the ocean floor. Why is this important? Don’t we already have a map of the ocean? Hasn’t Google already done that? Read more
Science Report 5 - Green flash – a rare and spectacular sight at sunset, Rio Grande Rise, South Atlantic
Some of you might have heard of the “green flash”—an upward flash of emerald-green light that appears for a few seconds just after the sun disappears beneath the horizon. It has a certain “wow effect” as this green light is a big surprise in a typical red-toned sunset. Read more
Science Report 3 - Isotopes crash course!
When people think of isotopes and radiation, images of nuclear plants and catastrophes sometimes go through their minds. Those are just one part of the story, however. Isotopes are actually very important to us geochronologists and geochemists when it comes to getting information out of rocks we have collected—such as the ones we’ve gotten on this science cruise. Read more
Science Report 2 - Rock Descriptions: Demystified
Identifying and describing the rocks collected by a dredge is one of the most important steps of a cruise. The scientists do their sample selection for geochronology and geochemistry based on these rock descriptions in order to address the research questions summarized on the main page of this website. Read more
Science Report 1 - Reconstructing Earth: Magnetics and Magma
One of the scientific goals of the NBP1808 cruise to the Rio Grande Rise is to collect measurements that will improve the plate tectonic reconstruction of the opening of the South Atlantic. How is this done? We are able to measure magnetic anomalies originating in the oceanic crust, which lies 1000-4500 m below the ship. Read more
Read All Science Reports
Rio Grande Rise 2018 Expedition
Browse through a gallery of pictures from the NBP1808 cruise, showing life aboard the RVIB (Research Vessel Ice Breaker) Nathaniel B. Palmer as we explore the Rio Grande Rise off the coast of Brazil in the South Atlantic.


Co-PIs on the Rio Grande Rise project: (From left to right) Cornelia Class, Anthony Koppers (Chief Scientist), William Sager.

The members of the NBP1808 science team.
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Planned Cruise Track
This map shows the planned path of the ship as we make our way around the Rio Grande Rise. This map includes our detour to avoid the storm.
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Scientific Goals
  • Use 40Ar/39Ar geochronology to determine whether the Rio Grande Rise formed along micro-plates, as an age-progressive feature like most of Walvis Ridge, or from a short-lived large eruptive event
  • Investigate whether the Rio Grande Rise displays three geochemically distinct zones similar to the triple-zoned younger part of Walvis Ridge using major-trace element and Sr-Nd-Hf-Pb isotope data
  • Collect magnetic anomaly data to help strengthen the age model for the South American tectonic plate
  • Explore the formation of the Rio Grande Rise as shaped by plume dynamics and/or shallow tectonics
  • Determine whether the geochemical mantle sources are related to a zone of probably dense material at the base of the mantle called the African Large Low Seismic Velocity Province (LLSVP)
The NBP1808 editors: (left to right) Malik, David, Ellyn, and Matt.
A team of 17 students and scientists led by Chief-Scientist Anthony Koppers will be at sea for seven weeks, mapping and dredging troughs, cliffs, and seamounts in the Rio Grande Rise region off the southeast coast of South America. The team consists of 11 graduate students in geophysics, geochronology, and geochemistry; 4 undergraduates; 1 post-doc; and 3 professors from Oregon State University, Lamont-Doherty Earth Observatory of Columbia University, and University of Houston. Over the next few weeks we will keep you updated as we map and dredge the Rio Grande Rise and expand the knowledge of the general area.