"IAS TALK 8 01"
New Tools for Predictive Sedimentary Basin Dynamics: Developing a Community Sediment Model Rudy Slingerland1, James P.M. Syvitski2, and Chris Paola3 1Department of Geosciences, The Pennsylvania State University, University Park, PA, 16802 2Institute of Arctic and Alpine Research, University of Colorado, 1560 30th Street, Boul-der, CO, 80309-0450 3Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN, 55455 What is a Community Sediment Model (CSM)? An architecture for commmunity-generated, continuously evolving, open software A suite of interconnectable, numerical process modules able to simulate the evolution of landscapes and sedimentary basins, on time scales ranging from individual events to many millions of years. Supplemental modules for: Defining model domains, Defining boundary and initial conditions, and Post-processing. A modular modeling package, not a single model What is a Community Sediment Model? (cont) It will contain: conservation and rate laws expressing our present- best understanding of sedimentary processes; advanced high-order PDE and hybrid PDE/cellular solvers adaptable over many orders of magnitude of spatiotemporal scales; next-generation adaptive meshes that can readily accommodate these advanced algorithms as well as domain/boundary deformation involving exceedingly large strains; automated mesh and algorithm selection, time- stepping, and domain coupling. Warning/Peligro/Achtung! CSM is not a single, super-model of the Universe. A ‘one size fits all’ approach to sedimentary geology will not work Our problems require temporal and spatial resolutions that vary over many orders of magnitude The very nature of problems change with time-scale Weather prediction (analogy—one storm bed) is an initial- value problem whose sensitivity to initial conditions prevents it from being solved indefinitely far into the future Climate prediction (analogy---stratigraphic sequence) is a boundary value problem that can in principle be solved exactly Why do it? A focussed initiative in predictive sedimentary dynamics would help us: Improve assessment of risk from natural hazards such as landslides, mudflows, floods, and coastal storms Improve predictive capability at all scales of stratal architecture, and consequently improve our ability to explore and exploit energy and mineral source rocks and reservoirs Better manage natural scenic landscapes Understand the manner in which sedimentary basins and erosional landscapes control carbon and other elemental cycles Better interpret the record of global and regional climate change. Solve a class of problems presently unanswerable Why do it? A Community Sedimentary Model architecture: combines the best work of many specialists creates honesty in what modelers claim eliminates the endless rewriting of the same initial algorithms allows hypothesis testing and sensitivity experiments on key parameters enhances communication; a community is built. Why do it now? A critical mass of basic algorithms describing sedimentary processes is now available. The manpower and skills are now available. The sedimentary community is more integrated, more quantitative, and more connected with the climate, hydrological and ocean communities then ever before How can we do it? A grass roots realization of the need for and the promise of, a Community Sedimentary Model has arisen in at least four sub-communities: U. S. NSF identified a Community Sedimentary Model as a high priority research initiative in sedimentary geology. The NSF-funded MARGINS Program calls for “the progressive development of a community-level suite of earth surface dynamics models for mass routing, deposition, and morphodynamic prediction. U. S. Geological Survey calls for, “freely available, modular sediment transport code, containing state-of-the-art hydrodynamics and sediment algorithms…”. The U.S. Office of Naval Research wants a collaborative effort to develop an integrated predictive model for the shelf sedimentary system. How can we do it? NSF-Sponsored CSM Workshop in February, 2002—watch for announcement Example 1: Macrogeomorphology of Active Mountain Belts Wanted: Basic geometry of mountain belt & sediment fluxes Both as functions of tectonic and surface processes and changing BCs and ICs Example 1 Strongly asymmetric; steep front facing the Pacific Ocean Ridge-pole lies at about 3.5 km above sea level