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NSF
00-102 (Replaces NSF
00-12)
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Program NewsMarine Geology and Geophysics
The second competition for funding under the MARGINS Program was held in April 2000. The special Earth and Ocean sciences panel considered 25 proposals that met the program announcement criteria for inclusion in the MARGINS competition. However, these proposals were limited to only two of the four MARGINS initiatives for which detailed science plans are available (the "seismogenic zone" and the "subduction factory"). At the time this newsletter went to press no decisions had been made as to which of these proposals will be successful.
This winter the MARGINS' community has been actively planning for the two additional initiatives, i.e., "rupturing continental lithosphere", and "sedimentation and stratigraphy" (sed/strat) on the margins. For the latter, the community has chosen to focus on the entire "source-to-sink" system along selected transects. This will allow better understanding of the processes and the fate of the sediments from their origin at the weathering sites in the hinterlands to their sequestration on fluvial flood plains and their remobilization and ultimate sink on the continental shelf, rise and the basin floor. The stated goal of the sed/strat community is to discern the relationships among processes relevant to sediment production, transport, accumulation, and preservation on margins at multiple temporal and spatial scales, from turbulence to tectonics and from sedimentary fabric to sequence stratigraphy and basin analysis. In a late September workshop a set of site-selection criteria were identified by this community to pick self-contained systems that could serve as potential study areas. The criteria identified included the presence of strong forcing signals, active sedimentation spanning all of the source-to-sink environments, and preservation of high-resolution stratigraphic record. The sites also had to be "ready" to be investigated, i.e., existence of broad background information and manageable logistics for research, in addition to having societal relevance. The workshop participants selected seven primary and several allied sites where these criteria were met. During a "town" meeting at the AGU annual meeting in December the sed/strat community further discussed these potential sites, and based on community-wide evaluation via the Internet, narrowed the selection down to two "focus" areas for the source-to-sink studies (Papua New Guinea and New Zealand).
The first MARGINS "theoretical and educational" institute with the theme of "rheology and deformation" was held in January and attended by about 100 participants (including 16 non-US scientists). The agenda included state-of-the-science lectures from authorities on subjects that ranged from fault behavior to velocity fields, extension and strain partitioning, finite element modeling, lab studies of friction and rheology of brittle faults, role of fluids and more. The institute was considered an unqualified success by those in attendance. The theoretical institutes will play an important role in the educational component of the program _ ca. 50% of the attendees were students and post-docs.
The theoretical institute was followed by a workshop on the theme of "rupture of continental lithosphere" with the main objective of choosing the two "focus" sites for this theme. The group identified several essential and desirable attributes for the sites to be chosen, with additional logistical requirements. Five sites were discussed, which were narrowed down to two "focus" sites (the Gulf of California-Salton Sea system and the Northern Red Sea) that represent "end member" situations (non-cratonic vs. cratonic). A document outlining the science plan for this theme will be forthcoming. Results of these workshops and other information about upcoming meetings are also posted on the MARGINS homepage that is regularly updated (www.soest.hawaii.edu/margins/).
A second MARGINS theoretical institute on the theme of "inside the subduction factory" is planned for August 20-25, 2000 and will be held in Eugene, Oregon. It will bring together petrologists, seismologists, geochemists and geodynamicists to address primary problems in the operation of the subduction factory. The sed/strat community is also planning to hold a theoretical institute of their own later this year to educate the community about the chosen "focus" sites, to organize the broad design of a coordinated program, and to produce a detailed science plan (please consult the MARGINS web site for additional information about how to apply for attendance at this and other institutes).
The RIDGE Program is having an active year with several workshops, six of which are planned for the rest of the year. The symposium on results of the MELT II experiment, held at Brown University in March, was a striking demonstration of the multidisciplinary synergies that have developed around the MELT Program. The results of some of the planned workshops will be used in developing the science plan for the new RIDGE Program. We certainly hope that the community members will either attend one or more of these workshops or provide input to the RIDGE steering committee. A draft of the RIDGE 2000 Report is posted on the RIDGE homepage (ridge.oce.orst.edu) and the community is encouraged to comment. The MG&G Program participates in the interdivisional Earth System History (ESH) activity, a component of the US Global Change Research Program. The emphasis of ESH is the study of past climate changes and their effect upon the oceans, cryosphere and continental systems. Funds for the ESH program are contributed by NSF's Earth, Ocean and Atmospheric Science Divisions, the Arctic Section of the Office of Polar Programs, and the Paleoclimate Program of NOAA. ESH received proposals for over 150 different projects for the spring 2000 review cycle. Proposals within the marine system, including coral studies, totaled about 50, an increase of 40% over the previous year. At the time of writing of this report, the review process was still underway. Thematically, in the last few years ESH has seen the emphasis shift to high-resolution studies, with a focus on rapid change events. There is also a strong component to develop or improve geochemical tools to serve as proxies of productivity, sea surface temperature, and deep water sources and flow paths. The MG&G Program contributes about $2.7M annually to the ESH activity.
Staff changes: At the end of 1999, Connie Sancetta left NSF to enjoy an early retirement, although we promptly invited her back as an "expert" on a part-time basis to help us with the next cycle of ESH proposals. Recently, Dick Poore, a paleoceanographer with the USGS, has joined us on an inter-agency loan and will replace Connie as the lead for the ESH program in OCE. Rodey Batiza, a marine petrologist and currently professor at Hawaii Institute of Geophysics, has also accepted our offer to join the MG&G Program starting this fall.
Bil Haq (bhaq@nsf.gov) |
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