A - C
We propose an international collaboration to study hydrothermal venting on the ultra-slow spreading Arctic mid-ocean ridge system. The Gakkel Ridge is a key target for hydrothermal studies because it has distinctive geological characteristics as a result of ultra-slow spreading (full spreading rate of 3-7 mm/yr), and because it is hydrographically isolated from the rest of the world’s ocean basins, which has important implications for vent field biological communities. In addition, major portions of the Arctic mid-ocean ridge system lie in deep water (> 4000 m) under the ice pack, rendering them inaccessible to traditional deep submergence technologies. We are solving this problem by developing robotic vehicles that will be able to autonomously detect, localize, survey, and sample deep-sea vent fields under the Arctic ice pack. As a result, our project is technology intensive and involves a strong component of discovery while at sea, which, when combined with our scientific objectives produces a compelling project that is very much in line with the objectives and spirit of the International Polar Year. Our major scientific themes are the geological diversity and biogeography of hydrothermal vents on the Arctic mid-ocean ridge system. Our major technology theme is autonomous exploration and sample return with an explicit mandate to develop techniques and methods for eventual use in astrobiology missions to search for life under the ice covered oceans of Europa, a moon of Jupiter (through funding from the US NASA). Our plan is to stage a series of at least two expeditions to different portions of the Arctic mid-ocean ridge during the IPY period (2007-2008). A US-led expedition will target suspected hydrothermal vent sites under "permanent" pack ice at 85E and 9E on the Gakkel Ridge, and a Norway-led expedition will target sites in seasonally ice-free water over the Mohns Ridge. The results of these two expeditions will be combined to reveal systematic patterns regarding biogeography (through both community-level and genetic-level investigations) of vent-endemic fauna, to study the differences between basalt vs. peridotite hosted vent fields, and to improve our understanding of hydrothermal circulation at ultra-slow spreading plate boundaries where amagmatic extension and long-lived faulting are the dominant mechanisms. Through a combination of both traditional and novel instrumentation technologies we will conduct hydrographic surveys to constrain the size, shape, and composition of hydrothermal plumes in the water column above the vent fields. At the Mohns Ridge, the Norwegian led efforts will then proceed as usual for vent field studies in open water using an remotely operated vehicle (ROV). On the Gakkel Ridge the shape of the plume, and the location of the positively buoyant plume stem, in particular, will be used to localize the source vent fields to ≤ 100m, and this information will be used to guide autonomous surveys (with autonomous underwater vehicles - AUVs) to generate fine-scale microbathymetry maps and photomosaics of the vent fields. The photomosaic imagery will be used to identify immobile sampling targets, and an AUV equipped with a rudimentary manipulator/sampler will then be used to acquire immobile (e.g., sessile) samples. The PUMA and JAGUAR AUVs are presently under development at the Woods Hole Oceanographic Institution for this mission, with a customized AUV-mounted manipulator being developed at the University of Maryland's Space Systems Laboratory. The AUVs will be tested under the Arctic ice pack in summer 2006 from the USCG Healy. After the expeditions samples and survey data will be disseminated to collaborating scientists at various institutions within our international consortium, such that a comprehensive suite of measurements and analyses will be conducted. Our formal effort will conclude with an international workshop to disseminate our results and focus future initiatives. Major funding for our proposed research is already in hand (see Section 3.10) through the US National Science Foundation Office of Polar Programs (Arctic Natural Sciences section) and the US National Aeronautics and Space Administration. In addition, the Norwegian-led effort to find and study vent fields on the Mohns Ridge has already gotten off to a fantastic start with the major discovery of new vent fields during the summer 2005 field season (http://195.37.14.189/public_html/sciencewriteratsea/Norway2005/web-content/Navigation/press/Norway.html). Scientists and engineers in Japan and Germany will contribute to the project by providing key personnel and equipment for the various Arctic expeditions, and by collaborating in post-cruise analyses of survey and sample data. Summary provided by http://classic.ipy.org/development/eoi/proposal-details.php?id=173
ARCTIC VENTS EXPEDITIONS