Title : NSF 95-132 - Ridge Inter-Disciplinary Global Experiments Type : Program Guideline NSF Org: GEO Date : August 28, 1995 File : nsf95132 The National Science Foundation continues to support the development of the RIDGE (Ridge Inter-Disciplinary Global Experiments) Initiative and invites proposals directed toward the program elements below. This program announcement supplants all previous RIDGE announcements. The RIDGE Initiative is designed to integrate exploration, experimentation and theoretical modeling into a major research effort to understand the geophysical, geochemical and geobiological causes and consequences of the energy transfer within the global rift system through time. Its long-term strategy is to obtain a sufficiently detailed spatial and temporal definition of the global mid-ocean ridge system to construct quantitative, testable models of how the system works, including the complex interactions among the magmatic, tectonic, hydrothermal and biological processes associated with crustal formation. The RIDGE Program components are therefore intrinsically interdisciplinary, and are intended to complement existing ridge crest research by emphasizing an integrated, investigative approach that can be accomplished only with high levels of coordination. International activities through InterRidge will serve to increase substantially the effectiveness and the accomplishments of such a coordinated strategy for investigations of ridge crest processes. Detailed objectives and strategies related to each of the program elements of the RIDGE Initiative are developed in a series of documents, including the RIDGE Science Plan: 1993-1997 and RIDGE Biological Objectives 1993-1997, all of which are available from the RIDGE Office. NSF funding is divided between the Marine Geology and Geophysics and Biological Oceanography programs within the Division of Ocean Sciences. Assuming the present funding profile is maintained, approximately $45 million may be available over the next five years for RIDGE-related research. However, this funding information is intended only as guidance since the final recommendations are subject to the availability of funds for RIDGE. While the program elements are not given explicit priorities at this time, priorities may be assigned based on the actual level of resources available, the results of the merit review conducted by the Foundation, multiple Federal agencies cooperative research activities, international collaborations, and the availability of facilities necessary to conduct the proposed research. Proposals submitted to RIDGE should be prepared in accordance with the guidelines provided in the NSF publication Grant Proposal Guide, NSF 95-27. Proposals should also include a statement addressing the relevancy of the proposed study to the goals and objectives of the RIDGE Initiative. Proposals will be reviewed in accordance with established Foundation procedures and the four generral criteria described in the Grant Proposal Guide. General questions regarding RIDGE and requests for RIDGE documents may be directed to the RIDGE Office, University of New Hampshire, Rm 142 Morse Hall, Durham, NH 03824-3525; e-mail ridge@unh.edu; voice phone 603- 862-4051; FAX 603-862-0083. Updated information on RIDGE meetings, workshops and research opportunities are available on-line on the RIDGE World-Wide Web Server. Information regarding InterRidge and requests for InterRidge documents can be obtained from the InterRidge Office, Dept. of Geological Sciences, University of Durham, South Road, Durham DH1 3LE, United Kingdom; phone 44-191-374-2532; Internet: intridge@durham.ac.uk. Questions regarding proposal preparation and submission or the NSF review process may be directed to Dr. David Epp (phone: 703-306-1586; Internet: depp@nsf.gov), Marine Geology and Geophysics Program, or Dr. Phillip Taylor (phone: 703-306-1587; Internet: prtaylor@nsf.gov), Biological Oceanography Program, National Science Foundation. Target dates for RIDGE proposals are February 15 and August 15. GLOBAL STRUCTURE AND FLUXES An important goal of the RIDGE Program is to characterize the geological, geophysical, geochemical and biological diversity of the mid-ocean ridge system on a global scale in order to identify the processes and factors that give rise to the observed variability. One objective of this effort is to develop sufficient understanding of the processes of crustal formation to estimate global energy and mass fluxes. The enormous scope of this task makes this program element a natural focus for a cooperative international effort coordinated with InterRidge; consequently, the global objectives of both RIDGE and InterRidge are inextricably linked. Based on the level of interest and priorities established through workshops convened by both the U.S. RIDGE and InterRidge communities, four areas have been identified for study: the Arctic Ridge, the Southwest and Southeast Indian Ridges, the Pacific- Antarctic Ridge, and the southern East Pacific Rise. Each of these areas is suitable for RIDGE global proposals. However, in an effort to maximize resources and achieve significant advances in the next five years, the primary focus of the RIDGE global effort will be on the spreading centers of the Indian Ocean (i.e. proposals for work on these spreading centers will receive highest priority under RIDGE Global studies), while that of the InterRidge global effort will be on the Southwest Indian Ridge. In particular, RIDGE encourages studies of magmatic, hydrothermal and biological processes in areas of the Indian Ocean for which other data already have been (or soon will be) obtained. RIDGE expects to support two or three major areas of effort over the next five years. Proposals are invited in the following areas: I. Field programs designed to characterize the structure, geochemistry, biology and energy fluxes on sections of the mid-ocean ridge system where data are sparse or lacking, with highest priority sites in the Indian Ocean. A complete field program should include reconnaissance surveys over a 1000-2000 km long section of the spreading center; as well as follow-up, more focused, studies of hydrothermal and biological processes once vent sites are located. Such a field study will require a multi-leg program over several years. Typical elements of a reconnaissance program include: multi-beam bathymetric and sidescan sonar mapping of the ridge axis; sampling and analysis of basalts from every segment; and water column sampling to determine the locations of hydrothermal activity. Typical elements of a follow-up, focused program include: more detailed water column studies, acoustic and photographic imaging, and sampling to document the nature of the hydrothermal activity and biological communities. Such programs will ideally focus on inter-segment comparisons over a broad region, in contrast to the narrower, regional focus of similar studies under the Crustal Accretion and Segment-Scale Processes program (see below). II. Analyses and syntheses of large data sets from a global perspective. In an effort to make the ever-growing bodies of data collected on the mid-ocean ridge system accessible to the community, RIDGE recognizes the need to support efforts aimed at the synthesis and dissemination of large data sets of diverse types. Currently, a synthesis of multibeam data from the East Pacific Rise (EPR), the NE Pacific, and the Mid- Atlantic Ridge (MAR) is in preparation. RIDGE has now identified for support the development of a petrologic and geochemical database of igneous and metamorphic rocks recovered from the mid-ocean ridge system. General guidelines for the development of such a database may be found in the RIDGE Petrologic Database Workshop report and supporting documents from the RIDGE office. III. Determination of global hydrothermal fluxes. Studies are encouraged along ANY ridge segment to examine the variability and relative contributions of heat and chemical fluxes from focused and diffuse axial flow, and from ridge flank systems to global hydrothermal fluxes. Examination of the interactions between biological and hydrothermal activity and the effects on productivity, diversity, biogeography, and chemical fluxes in these various settings are an integral part of this program. CRUSTAL ACCRETION AND SEGMENT-SCALE PROCESSES This part of the RIDGE program is devoted to understanding the interplay among the key variables in crustal accretion processes, and related magmatic, hydrothermal and biological activity operating at the scale of ridge segments. Over the next 3-5 years RIDGE will emphasize variations in spreading rate and magma supply as among the most important crustal accretionary variables, and acquisition of comprehensive data sets in a few primary study areas. The identification of key questions for priority study and the optimum sites for investigation emerged from workshops convened within the last few years, and investigators considering submitting proposals are strongly encouraged to obtain copies of the RISES, FLUXES and LARVE Workshop reports from the RIDGE Office. Proposals are generally invited, but the following four problem areas will receive the highest priorities from RIDGE in the period for 1996- 1999: I. The interplay among active magmatic, tectonic, hydrothermal and biological processes at the segment scale and their short- and long-term variability. RIDGE specifically encourages proposals to study hydrothermal processes and their interplay with magmatic and tectonic processes at sites of known vent activity along the slow-spreading MAR (particularly at sites discovered as part of the French-American Ridge Atlantic (FARA) program), the intermediate-spreading Juan de Fuca Ridge (JdFR), and along the fast and superfast spreading EPR at 9-10 degrees N and 17-20 degrees S respectively. Studies could include (i) mapping and sampling of volcanic, hydrothermal and biological features, with an emphasis on determining their relative ages; (ii) water column studies designed to quantify thermal, chemical and biological fluxes at the segment scale; (iii) segment-scale micro-seismicity studies, with an emphasis on distinguishing tectonic, hydrothermal and magmatic events; and (iv) detailed studies of individual hydrothermal sites using remotely operated vehicles (ROV) and/or submersibles to determine the distribution of deposits and organisms, and the temporal and spatial variability in characteristics of venting fluids, deposits and biological communities. In addition to the primary study areas on the MAR, JdFR and EPR, studies devoted to quantifying time scales and fluxes in other areas also will receive high priority. II. The origin of gravity bull's eyes (i.e. gravity lows centered on segment mid-points) and the spatial distribution and relative importance of magmatism, tectonism and hydrothermalism with respect to ridge segmentation at slow spreading ridges. Proposals are encouraged that address these issues specifically for the two segments immediately south of the Oceanographer Fracture Zone near 35 degrees N on the MAR. Proposals are invited for (i) swath bathymetry, gravity, and magnetics surveys over crustal ages from 0-2 Ma; (ii) on-axis deep-towed sidescan sonar surveys, ROV- based photography, CTD and other near-bottom remote sensing studies in selected areas of the two segments and associated offsets; (iii) on-axis geologic sampling and mapping; (iv) on-axis water column studies; (v) refraction seismics to measure overall crustal velocity structure; (vi) reflection seismics to image spatial and depth variations in internal structure of crust; and (vii) passive microearthquake and teleseismic studies. If evidence for hydrothermal activity is found on these segments, high priority will be given to mapping these sites, and to detailed investigations of all aspects of the associated hydrothermal and biological processes. Proposals for areas other than 35 degrees N that are specifically devoted to the controls on, and manifestations of, ridge segmentation at slow-spreading ridges are also encouraged, particularly for those problems for which it can be shown that other areas are more appropriate for study. III. The nature of the melt delivery and crustal plumbing system at fast spreading ridges, including whether it is fundamentally two-dimensional (2-D) or more three- dimensional (3-D) along axis. We specifically encourage intra-segment proposals for the EPR south of Clipperton (9-11 degrees 30'N) and/or the 17 degrees S MELT (Mantle Electromagnetic and Tomography Experiment) area that will provide: baseline geophysical studies including swath bathymetric mapping, sidescan sonar, magnetics and gravity; detailed petrologic sampling at approximately 1 km spacing on-axis and sampling of the 100,000 year isochron on at least one flank at ~2 km spacing; and seismic studies designed to image the region beneath the axial magma chamber or constrain crustal thickness variations that may reflect variations in magma supply along-axis. Proposals involving the direct study of lower crust and upper mantle near Hess Deep also are encouraged, specifically when these studies are directed toward the problem of melt delivery at fast spreading ridges. Example programs include sampling studies designed to address problems of lithologic structure, compositional variability and melt delivery in the lower crust and upper mantle, and studies that further define the relationship of lower crustal and upper mantle outcrops of Hess Deep to regional structure. Proposals for areas outside of EPR 9 -11 degrees 30'N, the 17 degrees S MELT area or Hess Deep that specifically address effects of varying magma supply at constant spreading rate and studies of transform- dominated regions where segment lengths are short relative to the length of the transform will also be given high priority. IV. The mechanisms of larval dispersal and gene flow of hydrothermal vent species, and the maintenance of their populations in vent habitats. A primary goal of segment-scale biological studies will be to investigate larval dispersal and gene flow in vent environments and evaluate the potential role of these processes in generating and maintaining biogeographic patterns along mid-ocean ridges and across ocean basins. Studies will be coordinated through the LARVE (Larvae At Ridge VEnts) Project to foster interdisciplinary approaches to studies of invertebrate reproduction and spawning, larval physiology and behavior at in situ pressure, flow effects on larval retention and dispersal, settlement processes and post- settlement interactions, intraspecific genetic variation and genetic differentiation across ecological and geological gaps in deep-sea hydrothermal vent habitats. The project will be focused near 9-10 degrees N on the EPR, but will extend to neighboring ridge segments. Further information can be obtained in documents from the RIDGE Office. In addition to sea-going field studies directed toward these problem areas, RIDGE will support shore-based programs of theoretical and experimental studies as well as field programs in ophiolites that specifically bear on the above questions. Shore-based programs might include: (i) modeling and laboratory studies of mantle-driven versus lithosphere-controlled mechanisms for ridge segmentation and segment evolution; (ii) modeling studies of the physics, rheology, and emplacement mechanisms of crustal magma plumbing systems; (iii) theoretical studies of the segment-scale interactions between hydrothermal and crustal plumbing systems; and (iv) ophiolite studies of three-dimensional exposures of lower crust and upper mantle and implications for ridge segmentation processes. MANTLE FLOW AND MELT MIGRATION The objective of this part of the RIDGE program is to constrain the nature of mantle flow and melt generation beneath mid-ocean ridges through a combination of field experiments, laboratory studies and numerical modeling. A central component of this program is the Mantle ELectromagnetic and Tomography (MELT) Experiment which is already underway and is designed to provide observational constraints on the nature of the melting region in the mantle and the pattern of upwelling beneath a mid-ocean ridge that produces the magma that ultimately forms the oceanic crust. Detailed descriptions of the experimental design can be found in the 1991 RIDGE Workshop report on Mantle Flow and Melt Generation, the 1992 report on the Model Design Studies for the MELT Experiment, the 1993 request for proposals for the MELT Experiment, all available from the RIDGE office, and an EOS article (EOS, 75, 537-540, 1994). The experiment will begin the data acquisition phase in October, 1995 with the deployment of about 50 ocean-bottom seismometers (OBS) in an array centered on the EPR at about 17 degrees S. In May-June 1996, the OBSs will be recovered and approximately 60 magnetometers and electrometers will be deployed for the magnetotelluric phase of the experiment. These instruments will be recovered in June, 1997. In late spring of 1997, the seismic data will be ready for distribution to funded investigators and, in early summer of 1998, it will be transferred to the IRIS Data Management Center and placed in the public domain. Similarly, it is anticipated that the electromagnetic data will be processed, archived and available to funded investigators about one year after recovery of the instruments and to the entire geoscience community about two years later. It is anticipated that late in 1997 or early in 1998 there will be a RIDGE workshop focusing on preliminary results from the MELT Experiment and related theoretical, experimental and observational developments. RIDGE invites proposals for additional work on problems related to mantle flow and melt migration in the following areas: I. Analysis of the MELT seismic data set, particularly those aspects that are not covered by the principal investigators of the MELT Experiment, including receiver function analysis, regional body wave propagation, local seismicity, and global surface wave propagation to the array. II. Laboratory-based studies to quantify the effects of partial melting on the physical properties and rheology of mantle materials and the composition of melts produced at small melt fractions and high pressures. III. Observational studies of the petrology and geochemistry of basalts and peridotites that can constrain melt production and migration processes. The report of the 1992 workshop on Physical Properties of Silicate Partial Melt identified five future directions of experimental research: the nature of liquid distribution in silicate partial melts; permeability, rheology, and magma transport; electrical conductivity of partial melts; seismic properties of partial melts; and constraints on physical properties of melt generation from MORB and abyssal peridotite compositional characteristics. Petrological observations overlap with other aspects of RIDGE such as Crustal Accretion Variables and Global Structure and Fluxes, but sampling of crustal and mantle rocks is strongly encouraged to focus as well on the melt generation process and constraining theoretical models of mantle flow. IV. Numerical and laboratory studies to develop three- dimensional models of mantle flow beneath ridges that can predict quantities that can be measured in observational experiments. These studies should incorporate: realistic surface geometry of plates; growth of plate thickness with age; pressure and temperature dependence of viscosity; buoyancy effects; time dependence; development of crystal fabric and seismic anisotropy; and interaction of flow from near- ridge hot spots. Models should make specific predictions of observable parameters such as topography, gravity, seismic travel times, electrical conductivity, and basalt composition so that observational experiments such as MELT can be used to test the theoretical models. EVENT DETECTION AND RESPONSE One objective of the RIDGE Initiative is the development and implementation of a strategy for practical and reliable event detection and response capability. This includes identifying, locating and characterizing ridge crest phenomena associated with intrusive and extrusive volcanism that can lead to catastrophic release of heat and chemical mass into the water column, and major earthquake swarms. Detection capabilities on the scale of multiple first-order ridge segments will employ acoustic/seismic methods and will rely heavily on the analysis of signals recorded by the U.S. Navy network of permanently installed hydrophone arrays (SOSUS). Other techniques that will be applied to smaller-order ridge segments include water column monitoring and repeated high-resolution seafloor mapping and imaging using a variety of acoustic and optical sensors carried out on remotely operated vehicles or autonomous underwater vehicles (AUVs). Studies are encouraged in three high-priority areas: I. Repeat visits to currently or recently active mid-ocean ridge crest areas for continued event evaluation activities which may include: (1) verification of the nature and character of a detected event by collection of ground truth information; (2) repeat high resolution bathymetric and sidescan sonar mapping to establish the spatial limits of seafloor affected by an event; (3) microearthquake studies and geodetic measurements using bottom-moored instrumentation; and (4) water column studies to determine the nature of event- associated plumes, and (5) investigation of the changes in the vent biological community. Studies under (4) and (5) can include long-term measurements using self- recording instruments deployed at suspected sites of activity, or may be coupled with other investigations. II. Utilization of the data recorded by the permanent hydrophone monitoring network (SOSUS) of the U.S. Navy to detect events along the of Juan de Fuca and the Gorda Ridges of the NE Pacific and the northern MAR. Data are currently being collected for the Northeast Pacific by the National Oceanic and Atmospheric Administration (NOAA) and for the North Atlantic by the Naval Research Laboratory (NRL). III. Development of innovative experiments and approaches to event detection monitoring for other remote areas of the mid-ocean ridge including superfast-spreading segments along the southern EPR. Proposals are invited in four general areas: (1) Synthetic Studies: theoretical and computational studies are required to better understand T-phase generation and propagation for mid-ocean ridge earthquakes. (2) Data Analysis: development of new interpretational approaches for SOSUS and other pertinent hydrophone data are needed to improve event discrimination and increase understanding of the role of earthquakes in the crustal accretion process. Possible areas of research include, but are not limited to: space-time pattern of event sequences, recovering source characteristics from T-phases, body wave identification and interpretation, and matched field event detection. (3) Verification of recorded SOSUS events: data from other studies should be used to verify the nature and character of seismo-acoustic events recorded by the SOSUS array or other hydrophone arrays, and aid in their interpretation. Studies under this category could range from a comparison of SOSUS data with results from other global or regional seismic networks to site- specific seafloor mapping and/or sampling studies to characterize the nature of a particular seismo-acoustic event, or otherwise detected volcanic event on a mid- ocean ridge crest. (4) Rapid Response Proposals and Letters: responses to events will be dependent on the type of event detected, on the timing of the event relative to any weather window, and on the availability of facilities. Multibeam, sidescan and/or photographic mapping could be combined with water column temperature and chemical scanning, seismic monitoring, and ROV and/or submersible studies of volcanic, tectonic and hydrothermal activity. Because of the many variables involved in evaluating and conducting an event response effort, and the rapid pace at which decisions must be made, RIDGE does not want to limit the eventual type or extent of any future response effort. Since the necessity of responding rapidly may preclude proposal submission followed by the normal NSF six- month peer review process, Event Response proposals will be reviewed prior to an event if possible. Event Response proposals should detail the expected response effort, potential coordination with other efforts, and the required timing relative to the event. The proposals should be for three years and should request both a small (less than $20,000) up-front award to cover minor equipment and preparation requirements, and a supplementary award for the actual response effort. When an event response is deemed appropriate, the RIDGE Event Response Subcommittee will work closely with NSF to select appropriate Event Response proposals and to coordinate the response. Event response efforts that require extensive development of preparation of equipment prior to an event should be discussed with the appropriate NSF Program Manager. In addition to Event Response proposals submitted to NSF, RIDGE encourages submission of letters of interest to participate in an event response effort, or for the design of an experiment that pertains to the geological, geochemical, geophysical or biological assessment of a mid-ocean ridge event. These brief statements should provide a summary of disciplinary expertise, approaches to be taken in data analysis, and technical specifications of any equipment that could be provided to monitor the event, either long- or short- term (e.g. bottom cameras, temperature arrays, in situ chemical scanners, seismic monitoring instruments {OBH, OBS}). Letters of interest should be submitted to the RIDGE Office and will be used by the RIDGE Event Response Subcommittee both to ensure that the necessary proposals have been submitted to NSF, and to augment a response if necessary. For more details, see the RIDGE workshop report, "Characterization of Mid-Ocean Ridge Earthquake Activity Using Acoustic Data from the U.S. Navy Permanent Hydrographic Arrays" and the report of the "1993 Meeting of the ED&R Working Group," both of which are available from the RIDGE Office. Analysis of SOSUS or other appropriate hydrophone data and its application to mid-ocean ridge event detection also provides opportunities for post-doctoral research through the RIDGE Postdoctoral Fellowship Program (see details in a later section). Information concerning the NOAA program is available from Dr. Christopher Fox, NOAA/PMEL/OERD, Hatfield Marine Science Center, Newport, OR 97365; phone 503-867-0276; Internet: fox@pmel.noaa.gov, and information concerning the NRL program is available from Dr. Clyde Nishimura, Naval Research Lab, Code 7420, Washington, DC 20375; phone 202-767-0379; Internet: clyde@hp8c.nrl.navy.mil. TEMPORAL VARIABILITY OF RIDGE CREST PHENOMENA An objective of the RIDGE Program is to improve our understanding of ridge crest processes by direct experiments or observations of phenomena that occur on time frames from milliseconds to decades. This portion of RIDGE is designed to obtain time-series measurements that can stimulate the generation of hypotheses and the testing of resulting models relating to the temporal variation and covariation among dynamic, interconnected ridge crest processes. This will require the development, testing and long term deployment of instruments for making time-series observations of magmatic, volcanic, tectonic, hydrothermal, and biological phenomena. The major focus of this program element for the next five years will be the RIDGE Observatory Experiment (ROBE). This will provide the framework and infrastructure needed for successful conduct of a large number of co-located, interrelated active process investigations. The basic approach will be to encourage and facilitate coordinated projects proposed and executed by individuals or small groups of investigators. The highest priority will be given to proposals that have bearing on covariation among processes and which address problems that can be related to other ridge crest time-series experiments. Two segments of the JdFR, Cleft and Endeavour, are the sites at which ROBE will be implemented. Both have been intensively studied for more than a decade and between them they encompass a wide range of ridge crest phenomena. Cleft, with its comparatively simple morphology, both stable and transient hydrothermal sites, and recent volcanic activity, provides a region in which the interplay between tectonic, volcanic and hydrothermal processes can be studied. Endeavour displays greater morphological complexity, larger accumulations of hydrothermal deposits and greater biological diversity, but lacks evidence of recent volcanic activity. Time-series projects of various kinds have already been initiated in both segments. While these two are the sites for ROBE, Temporal Variability proposals for work at other locations will be considered if neither the Cleft nor the Endeavour segment is suitable for the proposed experiment. However, high relevancy will be given only if a strong case is made within the proposal for placing the experiment apart from the focus sites. In addition to the focus on long-term monitoring at the ROBE sites, the existence of SOSUS data made available to the scientific community by the NOAA VENTS group at Newport, OR, or others, provides the opportunity for coordinated time-series measurements in response to events that occur along the entire JdFR. This portion of ridge crest time-series studies represents a merging of the activities of the RIDGE Temporal Variability and the Event Detection/Response program elements and permits initiation of observations immediately after an event has occurred. These long term observations of ridge crest phenomena in response to "transient" events will complement observations of the more "steady-state" phenomena being measured at the focus sites. Both components are required to understand the interrelationships among physical, geological, chemical and biological phenomena involved in ridge crest processes. It is also recognized that a strong theoretical modeling component is required to complement the seafloor time-series measurements. Development and testing of models of physical, chemical, geological and biological processes, and their covariation, at scales of centimeters to tens of kilometers in submarine volcanic-hydrothermal systems and the overlying water column is an essential element of the program. Background information is contained in RIDGE workshop reports and RIDGE Events articles, and a topography data base for the northeast Pacific, with emphasis on the JdFR, is available on Internet. Proposals are invited to address four issues: I. Crustal Processes. Studies designed to understand the present tectonic and magmatic development of the Cleft and Endeavour Segments, to monitor active volcanic/magmatic/hydrothermal processes, and to conduct time-series measurements of seafloor and crustal processes are needed to develop integrated crustal accretion models at the segment scale. Specific measurements envisioned include: geodetic (strain, tilt, gravity), seismic (earthquake and active), and repeat mapping (sidescan sonar, camera tows, petrologic sampling, fluid sampling, vent temperature monitoring). II. Hydrothermal and Biological Processes. Studies are needed to quantify the seafloor hydrothermal mass and energy fluxes, the relative contributions of focused and diffuse hydrothermal venting, the variability in these sources and effects over time, and the interrelation of these sources with biological production and community structure. To address these issues, measurements are envisioned of temperature, effluent velocity, and fluid composition at numerous locations within an active vent field. Detailed mapping and repeat mapping at scales of centimeters to hundreds of meters of the distributions of, and relationships among, lava flows, faults and fissures, sites of diffuse and focused fluid flow, hydrothermal deposits, and biological organisms is needed. Both diffuse venting and focused higher temperature effluent should be monitored and sampled. Fluids should be analyzed for major, minor and trace elements, and for dissolved gases and nutrients. Estimates of the biological production supported by the hydrothermal fluxes, both in the interstices of the crust and exposed on the sea floor, should be made. Relevant biological studies might address the nature and controls on short term production variability, the relationships between productivity and the thermal/chemical energy supplied by hydrothermal fluids, estimation of the fraction of biological production exported to the deep sea, and the community response to production and flux changes. III. Water Column Processes. Studies are encouraged to assess the integrated thermochemical fluxes from vent system plumes, the temporal variability of plume structure, entrainment rates, vorticity dynamics, and regional circulation patterns. Other areas of interest are the chemical and biological processes transforming plume constituents, the resulting biological production and its contribution to total hydrothermal organic carbon production, and the impact of these processes on water chemistry and ecology. Studies will focus on characterization of plume fluxes, long term variability, detection of anomalous events and related process investigations. To address these issues a range of water column time-series are envisioned. Continuous measurements should include moored temperature recorders, current meters, sediment traps, and optical sensors as well as scintillation and video flow measurements. Specific chemical components measured may include: metals, inert and reduced gases, nutrients, microbiological biomass and activity rates. Repeated surveys should be conducted including tow- yo's of CTDT, dissolved and particulate tracers, bio- acoustic plume surveys, and AUV-deployed sensors on repeated survey tracks. Experiments to understand physical plume processes, from the local vent scale to the ridge segment scale, might include ADCP profiling, buoyant plume studies and Lagrangian drifters. IV. Theoretical Modeling. Studies should focus on understanding the underlying structure and dynamics of submarine volcanic-hydrothermal systems and subsystems, with an emphasis on making testable predictions about their origins and evolution. Models will be developed theoretically, using laboratory simulations, numerical experiments or some combination of these approaches, and will then guide the design of field programs and the interpretation of the data collected. It is hoped that integration of separate models will lead to an understanding of the interdependence over the life of the systems of the volcanic, tectonic, hydrothermal, biological, and water column processes. CROSS-CUTTING THEMES There are a number of problems of high priority to RIDGE that cross- cut the program elements described above, primarily because studies at a variety of spatial and temporal scales are required in order to address them. Although they have been referred to in the various program elements, the nature of the problems and the types of studies encouraged by RIDGE are presented in the following three sections. Fluxes Associated with Hydrothermal Activity and their Global Impact The mass and energy fluxes associated with hydrothermal circulation of seawater through the oceanic crust may be globally significant for many geologic and oceanographic processes. However, there are a number of key scientific questions that must be addressed to assess the global impact of hydrothermal systems both on the present-day ocean/atmosphere system, and during the past when different climatic and oceanographic conditions prevailed. The RIDGE Program has identified six problems that need to be addressed through a combination of field studies at varying spatial and temporal scales, laboratory experiments, and numerical modeling (see the RIDGE/VENTS Workshop Report on "Global Impact of Submarine Hydrothermal Processes" available from the RIDGE Office): I. The partitioning of flow between diffuse and focused vents at the ridge axis. The relative distribution of these two types of flow and their importance in mass and energy fluxes is currently unknown. The percentage of heat loss from hydrothermal venting is not well established and is of importance to both the global chemical flux calculations as well as to the benthic bioproductivity associated with these systems. Addressing this problem will require mapping of the distribution of various types of venting at the segment- scale, as well as development of instrumentation to measure fluxes in diffuse flow at individual vent sites. II. The magnitude of flank fluxes. The ridge flanks account for approximately 75% of the heat flux, and a large seawater flux. Slight anomalies in composition from seawater can have a large oceanic effect because of the volume of water involved. However, the chemical nature of this flow is not known. Research is needed to investigate hydrothermal processes on the flanks of ridges and to determine the magnitude and nature of the associated chemical and energy fluxes. III. Event fluxes. Megaplumes and events of catastrophic submarine volcanism are documented, but there is no quantitative estimate of global or regional vertical transport by these processes since the frequency of such events is unknown. Detailed studies, both on the scale of individual events and at the segment-scale, are required to assess the mass and energy fluxes associated with these events, and their variability over time. IV. Physical chemistry of Fe in the ocean. The hydrothermal input of Fe into the ocean may be very significant, as Fe may act as a limiting nutrient in primary productivity. However, in order to assess these issues, laboratory studies are required to provide basic information on the physical chemistry of Fe in the marine environment. V. Physical oceanographic effects. Two significant issues involved with the linkage between hydrothermal flux and physical transport processes in the ocean are the impact of hydrothermal discharge upon deep ocean circulation, and the mechanisms by which the benthic hydrothermal flux can be transported into upper ocean levels. To understand the former, a global assessment of the spatial and temporal distribution of hydrothermal heat flux is required. To understand the latter, measurements of the heat flux associated with the buoyant hydrothermal fluid that gives rise to the vertical transport of hydrothermal material are needed. VI. The significance of biological processes in controlling chemical fluxes. The chemical fluxes that are most important to vent biota are sulfides, methane, hydrogen, carbon monoxide, iron and manganese, as well as many other trace elements. However, at present, there are no models to predict the percentage of the flux of biogenically important metabolites that is utilized by organisms in a given vent field. Models of micro- and macrofaunal productivity at vent and ridge flank environments are required to understanding the significance of biological controls on chemical fluxes. Biological Activity and its Interaction with Physical/Chemical/Geological Processes Another cross-cutting theme in the RIDGE program is the interaction between biological and physical, chemical and/or geological processes. These problems can be addressed by studies ranging from the global scale to the scale of an individual hydrothermal vent, and involve investigative strategies ranging from one-time mapping and sampling efforts to long-term in situ observations. Five major goals for biological studies have been identified as having a high priority within RIDGE (see the report on RIDGE Biological Objectives 1993-1997 available from the RIDGE Office): I. To understand the mechanisms of vent organism dispersal. One of the fundamental questions concerning the unique biological communities associated with deep-sea hydrothermal vents is how the organisms associated with vent environments locate and colonize these ephemeral habitats. This is the primary goal of the LARVE project which is part of RIDGE's Crustal Accretion and Segment-Scale Studies. However, many aspects of this problem will be addressed by other components of RIDGE. For example, global-scale biological studies may identify new vent communities along previously uncharted sections of the global ridge system and thus constrain the distribution and species composition of vent communities on a global (biogeographic) scale. Event response and observatory studies, like those conducted at 9 degrees 50'N on the EPR and at Co-Axial segment on the JdFR, hold the potential to provide unique constraints on the establishment or regeneration of a hydrothermal vent ecosystem immediately following a seafloor eruption. II. To delineate the relevant trophic mechanisms and pathways of vent organisms. Determination of the pathways and mechanisms involved in the synthesis of organic material in hydrothermal vent communities, as well as the means by which chemical energy is obtained, are of fundamental importance to our understanding of these communities. The organic material produced by vent organisms can be used either by heterotrophic vent organisms or can be exported to the deep sea. Quantifying the significance of this transfer is essential to determining the relationship between these communities and the surrounding deep sea. Addressing these problems will require detailed studies in specific locales as is envisioned under Crustal Accretion/Segment-Scale and Temporal Variability Studies. III. To determine the influence of vent organisms on sulfide geochemistry and mineralization. The massive sulfide deposits formed at hydrothermal vents act as the substrate for many vent organisms. Vent organisms may influence sulfide mineralization by locally modifying the chemical environment, for example through oxidation and reduction of sulfur, metals, carbon, and subsequent modification of pH. Vent organisms may also significantly modify the physical environment, both directly through their presence modifying porosity and fluid mixing, and indirectly through modification of mineral precipitation. These interactions are still very poorly understood and research is needed to quantify the influence of vent organisms on geological processes in hydrothermal systems ranging in scale from a single chimney to a hydrothermal deposit. IV. To determine the relative influences of biological interactions and physical, chemical and geological processes on the distribution and abundance of organisms. Physical and chemical parameters play a profound role in the describing the distribution of animals at hydrothermal vents due to both the toxic and nutritive aspects of vent waters. Research addressing the habitat characteristics that are required or tolerated by hydrothermal vent organisms is central to an understanding of vent communities. However, within this context, the next important step is to address a variety of biological interactions (e.g. colonization, competition, and predation) that may modify physical/chemical controls and play a role as determinants in faunal distribution. V. To acquire a global biogeographic description of vent organisms. A global biogeographic description of vent fauna is essential to an understanding of the evolutionary biology of vent organisms. Exploration of new vent sites specifically for biological purposes may not always be feasible, but more limited surveys and/or sampling efforts can be conducted during other RIDGE cruises with the samples being preserved for later study. This objective will thus be closely tied to RIDGE Global Structure and Fluxes studies. Theory, Experimental and Modeling Studies Theoretical, experimental and modeling studies are essential to all of the major RIDGE program elements. While RIDGE has a strong field orientation, the collection of more data will not alone lead to substantial progress. The right data must be collected; the data collected must be able to be converted into real physical constraints on processes and structure; and the data must be available in a form which make them accessible to a wide variety of investigators in a timely fashion. All of these aspects require a significant effort on shore by investigators, most of whom may not be directly involved in the field programs. This effort can be put into three broad categories: I. Testable models need to be developed that can be used to guide the design of field programs and to interpret the data collected in these studies. The ultimate goal is the formulation of specific, testable hypotheses using time-dependent, three-dimensional models that incorporate accurate descriptions of the relevant physical processes and material properties. These models may be developed theoretically, using laboratory simulations, numerical experiments or some combination of these approaches. II. Laboratory measurements of physical properties and equilibria among multiphase systems are needed to properly interpret the data collected in the field and to constrain quantitative models. III. A long-term program of data archiving and sample curation is necessary to insure accessibility of data sets collected in RIDGE programs. POSTDOCTORAL FELLOWSHIP PROGRAM The RIDGE Postdoctoral Fellowship Program is intended to foster cross-disciplinary fertilization by providing opportunities for individuals to broaden their research experience into areas other than those that formed the foci of their Ph.Ds. One intent is to encourage those who are already working on ridge crest problems to apply their expertise to different problems in a related field. For example, a seismologist who has been involved in field programs to investigate melt generation beneath mid-ocean ridges might propose to work in an experimental lab that is investigating the physical properties of partial melts. A geochemist who has worked on the mineralogy of hydrothermal vent deposits and its relation to fluid chemistry might propose to work with a biologist to determine how the activity of organisms affects the growth and geochemistry of chimney structures. A theoretician who has developed models of faulting might propose to work with a structural geologist or geophysicist to conduct seafloor geodetic measurements. Another intent is to provide opportunities for scientists from disciplines outside the marine field to focus their conceptual and technical expertise on a high priority objective of the RIDGE Initiative. The Fellowships are designed so that recipients can choose the research environment most beneficial for their scientific development and that of the RIDGE Initiative. Applicants are normally expected to submit a research plan that requires a change of institution from the doctoral institution. It is expected that up to two fellowships will be awarded each year. Eligibility You are eligible to apply for a National Science Foundation RIDGE Postdoctoral Fellowship if (1) you have earned the doctoral degree in a relevant scientific discipline within one year of taking up the award; and (2) you have made prior arrangements for research with a scientific advisor/collaborator at the institution where your Fellowship will be held. Since the Fellowships are designed to provide opportunities for interdisciplinary and/or cross-disciplinary studies, the adviser's area of expertise should be different from that acquired in your previous research training. Location of Work The RIDGE Postdoctoral Fellowships will be awarded for scientific research at any appropriate non-profit United States institution. Appropriate non-profit institutions in this program include institutions of higher education as well as government laboratories, national laboratories, and privately sponsored nonprofit institutions. All arrangements for affiliation with a senior scientist and Fellowship institution are the responsibility of the Fellow. A statement from the senior scientist with whom the Fellow plans to work, indicating both a commitment for the necessary facilities and consultation during the requested tenure period, is required. The awards will be made to the institution in the name of the Fellow, with the Fellow as principal investigator, or co-principal investigator and the advisor as principal investigator if the institution mandates. Tenure, Stipends, Allowances and Conditions. The Postdoctoral Fellowships will be awarded for a two- year period. The Fellowship provides a stipend, an institutional allowance, and a special allowance to aid in defraying costs associated with the research. The Fellowship stipend will be $35,000 for twelve months per year. The institutional allowance (in lieu of indirect costs) of $300 per month of tenure is for partial reimbursement for expenses incurred in support of the research (such as space, equipment, secretarial assistance, and general purpose supplies). The special allowance of $5,000 per year is expendable at the Fellow's discretion and is intended to be used for scientific equipment and supplies, travel, publication expenses, other research-related costs, and may be used for medical insurance. Tenure will start upon request by the Fellow after acceptance of an award offer, but not later than January 1 of the following year. Fellows will be expected to devote full time to appropriate scientific research and training during the tenure of the Fellowship and to pursue the program for which the Fellowship was awarded. Major changes in the plan of scientific research, in tenure, or in Fellowship institution require prior Foundation approval. Institutions may supplement Fellowship stipends without prior permission from the Foundation provided that such is done in accordance with established institutional policies. Supplementation may not be conditioned on any requirement for duties in addition to normal Fellowship activities and may involve teaching only to the extent of conducting or participating in seminars directly related to the Fellow's research program. Evaluation and Selection of Fellows The evaluation of applicants will be based on ability as evidenced by past research work; suitability and availability of the sponsoring senior scientist and other associated colleagues; suitability of the host institution for the proposed research; likely impact on the future scientific development of the applicant; scientific quality of the research likely to emerge; and the potential impact of the research on the RIDGE Initiative. The criteria listed above will be used by a panel of scientists convened by NSF, with representatives from appropriate disciplines, to evaluate the proposals submitted. In addition, the applications will be reviewed by a RIDGE committee that will assess the relevance and priority of the proposed research to the RIDGE Initiative. Application Procedures and Materials To be eligible for consideration, applications for the Fellowship Program must be complete and submitted to the NSF at the normal RIDGE target dates. Requirements for proposal format cited in the Grant Proposal Guide (NSF 95-27) generally apply. In addition, Fellowship applications must include within the 15-page limit: (1) a personal statement (not to exceed two single-spaced pages) that describes the career goals of the applicant and what role the chosen research, sponsoring/collaborating scientist and host institution will play in enhancing the applicant's conceptual approach and technical skills; (2) a short abstract of dissertation research and planned publications; and (3) a statement from the sponsoring/collaborating scientist at the proposed host institution indicating agreement to work with the applicant if the award is made. Additional Information The Foundation provides awards for research in the sciences and engineering. The awardee is wholly responsible for the conduct of such research and preparation of the results for publication. The Foundation, therefore, does not assume responsibility for the research findings or their interpretation. The Foundation welcomes proposals from all qualified scientists and engineers, and strongly encourages women, minorities, and persons with disabilities to compete fully in any of the research and related programs described here. In accordance with federal statutes, regulations, and NSF policies, no person on grounds of race, color, age, sex, national origin, or disability shall be excluded from participation in, denied the benefits of, or be subject to discrimination under any program or activity receiving financial assistance from the National Science Foundation. Facilitation Awards for Scientists and Engineers with Disabilities (FASED) provide funding for special assistance or equipment to enable persons with disabilities (investigators and other staff, including student research assistants) to work on an NSF project. See the program announcement or contact the program coordinator at (703) 306-1636. Upon completion of the project a Final Project Report (NSF Form 98A), including the Part IV Summary, will be required. Applicants should review this form prior to proposal submission so that appropriate tracking methods are included in the proposal plan to ensure that complete information will be available at the end of the project. Privacy Act and Public Burden Information requested on NSF application materials is solicited under the authority of the National Science Foundation Act of 1950, as amended. It will be used in connection with the selection of qualified proposals and may be used and disclosed to qualified reviewers and staff assistants as part of the review process and to other government agencies. See Systems of Records, NSF-50, "Principal Investigator/Proposal File and Associated Records," and NSF-51, "Reviewer/Proposals File and Associated Records," 56 Federal Register 54907 (Oct. 23, 1991). Submission of the information is voluntary. Failure to provide full and complete information, however, may reduce the possibility of your receiving an award. The public reporting burden for this collection of information is estimated to average 120 hours per response, including the time for reviewing instructions. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to: Herman G. Fleming Reports Clearance Officer Contracts, Policy and Oversight National Science Foundation 4201 Wilson Boulevard Arlington, VA 22230 and to: Office of Management and Budget Paperwork Reduction Project (3145-0058) Washington, D.C. 20503. The National Science Foundation has TDD (Telephonic Device for the Deaf) capability, which enables individuals with hearing impairment to communicate with the Foundation about NSF programs, employment, or general information. This number is (703) 306-0090. OMB: 3145-0058 and 3145-0023 P.T.: 22 K.W.: 1008004, 1008000 NSF 95-132 (Replaces NSF 93-134)