The drilling crew prepares the drill string for coring. Photo courtesy of the Joint Oceanographic Institutions.
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Jeff Fox,
Director of Science Operations Much to my surprise and delight, I have found that living in Texas, in general, and in the land of the Texas A&M Aggies, in particular, has not been deleterious to my or my family's Yankee-bred health. Fond memories of my 14 years at GSO/URI, and the collegial environment of the Bay Campus, have helped bridge the challenges associated with relocation, adjusting to a major careeer change, and building a house. |
The resources of ODP are finite, and every effort is made to ensure that only the best and most compelling scientific questions are addressed. The international community of scholars who determine the investigative strategies and the scientific priorities for the program have created a long range plan establishing a course for the program into the 21st century. Two major themes have been defined: Dynamics of Earth's Environment and Dynamics of Earth's Interior. Within each theme, several core endeavors and specific initiatives are identified that capitalize on new scientific frontiers, interdisciplinary approaches, greater collaboration with international geoscience programs, and enhancements in drilling technologies.
Dynamics of Earth's Environment: Understanding the climate system, and its response to factors such as global warming from greenhouse gases, is critical to the future of humankind. The program will investigate decade-to-century time scale variations by collecting long and extremely high-resolution sedimentary sections. These data will allow ODP to investigate the relative sensitivity of climate to greenhouse gases and Earth's orbital changes, the role of polar ice sheets in regulating climate change, and the history of Pacific and Atlantic deep waters. During the next five years, a high priority of ODP is to provide scientists with the following: 1) a first-order global sampling of key climatic systems so that decade-to-century scale variations in climate and their impact on sea-level changes can be resolved, 2) cores from stable areas of seafloor where high-resolution, orbitally tuned geologic time scales can be established extending to at least 40 million years ago, 3) sampling transects to better define northern and southern hemisphere heat transport. These high resolution data will allow us to resolve how the Earth climate system in the past has responded to a variety of changing factors. These insights, in turn, will allow scientists to understand how the Earth's climate system is likely to respond in the future.
Variations in the chemical composition of sediments deposited through time, the nature of subsurface fluids, and the biochemical process associated with bacteria within the substrate all act to change Earth's environment in ways that are appreciated but still poorly understood. A high priority for ODP will be to focus on the cycling of carbon through the ocean, atmosphere, and landmasses by recovering sediments from key intervals in Earth's history when extreme perturbations in the carbon cycle and climate are known to have occurred, and to explore the distribution, extent, and formation of gas hydrates, a major carbon reservoir trapped in the sediments of the submerged continental margins. ODP will also explore the interactions of fluids, sediments and bacteria, and how these physical, chemical, and biological processes react in time and space to create mineral deposits, hydrocarbon reservoirs, and global geochemical cycling.
Earth's deep biosphere represents a new and exciting pilot project. Bacteria live in sediments at depths of at least 1,000m below the seafloor, and in volcanic rocks along mid-ocean ridges. In fact, some investigators suggest that the biomass of the bacteria in these environments may surpass the biomass known to inhibit the more familiar environments on our planet. ODP will explore the distribution, depth, extent, and genetic range of the deep biosphere, in order to understand its biology, ecology, and contribution to the global carbon budget. Another goal in the next five years will be to implement hydrogeological experiments addressing the magnitude of fluid flow and geochemical cycling in different tectonic settings.
Dynamics of Earth's Interior: ODP will focus on mantle dynamics, the formation and structure of oceanic crust, hydrothermal processes and sulfide mineralization, crustal alteration, and recycling of material at subduction zones. Moreover, it is planned that in the next five years ODP will have laid the foundations of a global network of seafloor borehole seismic observatories, as part of the International Ocean Network designed to improve our understanding of Earth's dynamic interior. ODP will also quantify the substantial interior-to-surface energy transfer represented by the emplacement of Large Igneous Provinces, regions of the Earth where massive outpouring of magma have taken place in the geologic past.
A long-standing problem in marine geology is the deep structure and composition of the oceanic crust because these elements have been difficult to directly observe or sample. A major goal for the Program is to compare the structure of fast and slow spreading crust down to depths of about 3km, quantify the mass and heat budgets associated with the formation of oceanic crust, and test the geophysically determined model of oceanic crust. The oceanic crust that is created along the axis of the world-encircling mid-oceanic ridge system results in vigorous hydrothermal circulation and chemical reaction of hot rocks and seawater. These processes are responsible for the exchange of heat and mass between the lithosphere and hydrosphere. Assessing these exchanges requires long-term monitoring of subsurface physical, chemical, and hydrogeological processes within the oceanic crust. Hydrothermal circulation leads to the formation of massive sulfide deposits, a potentially valuable source of certain metals. A goal during the next five years will be to provide scientists with the data to determine the structure of a sulfide deposits and to support setting up a ridge-axis observatory designed to monitor key processes.
Subduction at convergent plate margins is the mechanism by which sediment and crustal material is recycled into the mantle. ODP will provide scientists with the means to determine subduction zone fluxes by quantifying both the inputs (oceanic sediment and crust) and the outputs (volcanic sediments, fluids and magmas). An ongoing initiative is to produce estimates of subduction fluxes at Pacific convergent margins during the next five years. The processes associated with subduction have formed some of the largest mountain ranges, and an ongoing goal is to establish the links between deformation, fluid flow and exhumation during convergence and mountain building. Some of the largest earthquakes in the world are associated with convergent margins, and ODP aims to advance the understanding of earthquake mechanisms by providing the necessary boreholes and hardware support for scientists to carry out in situ monitoring of key physical properties involved in faulting. A major goal is to understand the initiation and propagation of earthquakes at a convergent margins, and the relationship between fluid flow and geohazards.
Understanding the processes that give rise to the structure and stratigraphy of continental margins that form by the splitting of a large landmass, specifically the partitioning of deformation due to strain, is a key ODP objective. ODP aims to investigate the mechanism of how continents break up, and the nature of the boundary between the continetns and oceans by direct sampling of the deepest portions of shallow continental margins (especially pre-rift basement rocks, rift-related volcanics, and the oldest xsediments deposited on the margin).
If ODP is to be successful in executing this ambitious scientific plan during the next six years, some critical technologies and innovations will have to be implemented in the near future. Those developments include: higher resolution tools for enhanced imaging of drillholes; new technologies to increase drilling depth, hole stability and core recovery; and microbiological systems for better detection and on-board analysis. In addition, there is a need for improved techniques for collecting downhole logs of data at the same time that drilling is taking place, a better correlation of logging and coring data, and the development of advanced borehole observatories (instruments place in drillholes for long periods of time), for improved monitoring of active processes at depth.
The global ocean is this planet's last frontier. The JOIDES Resoluiton is to the history of the Earth contained in the seabed what the Hubble telescope is to astronomy and the history of the universe.
