GP17 (PACIFIC – South) Planning
U.S. GEOTRACES is planning to extend its meridional transect, initiated on the 2018 GP15 Alaska-Tahiti expedition, south to the Antarctic ice edge and then east to Chile. This transect was designated GP17 in the original series of the International GEOTRACES Program, but was not discussed in the US GEOTRACES basin planning workshops (2008-2009). Because of the potentially important TEI inputs and transformations occurring in Antarctic waters and shelves, GP17 will also have a second leg into coastal and shelf waters of Antarctica’s Amundsen Sea. A collection of slides illustrating the oceanographic features that motivate these cruises can be found here:
More detailed plans for the GP17-Ocean (GP17-OCE) and -Antarctic (GP17-ANT) expeditions were discussed at an online planning workshop held on 6-8 May, 2020. [Zoom mtg link]
To inform the discussions at the May planning meeting and to aid in proposal preparation, links are provided to all of the submitted statements of interest.
As of June, 2020, the management proposals for the two cruise legs have been recommended for funding. The cruise management team has made summaries from the management proposals, GP17-OCE and GP17-ANT available to aid in the submission of science proposals for the August 17, 2020 NSF Chemical Oceanography deadline. For those submitting proposals for the GP17-ANT cruise, the proposals will need to supply additional information to OPP. The list of priority parameters as approved by the US GEOTRACES SSC is also available
The rationale for the two legs of this cruise are:
- Complete the meridional transect of the Pacific Ocean begun on GP15 (2018)
- Capture deep Pacific Ocean inputs to the Drake Passage
- Further our understanding of shelf and slope processes in the Amundsen Sea
- Study the behavior and distribution of TEIs in the Amundsen Sea Polynya(s).
GP17-OCE and GP17_ANT cruise tracks
- GP17-OCE (in red)
The leg will begin in Papeete, Tahiti, work south to the ice edge in the western Amundsen Sea, continue sampling to the east, and then cross to Punta Arenas, Chile in order to sample the deep Pacific waters thought to supply TEIs to the Southern Ocean in the Drake Passage region.
- GP17-ANT (in orange)
The leg will depart from southern South America (Punta Arenas) and transit to the west end of the Amundsen Sea, where the ship will enter the ice. The cruise will study shelf and slope processes affecting TEIs, including the influence of Amundsen Sea Polynya(s). This work will require an ice breaker.
Click on GP17-OCE and GP17-ANT for links to a collection of slides that illustrate features that motivate a GEOTRACES study of this region