Basic Research Needs for Geosciences - Energetics Meetings and ...

GRAND CHALLENGE:INTEGRATED CHARACTERIZATION, MODELING, AND MONITORING OF GEOLOGIC SYSTEMSINTEGRATED CHARACTERIZATION, MODELING, AND MONITORINGOF GEOLOGIC SYSTEMSABSTRACTTo seriously consider geological opportunities for waste sequestration, public health and safetydemand a uniformly excellent characterization of potential subsurface sites. Subsurface systemspose some of the most challenging characterization and modeling problems in science. Thechallenges arise largely from the inaccessibility and complexity of the subsurface system, a widecontinuum of relevant scales of variability, the potential role of coupled nonlinear processes, andthe importance of detailed results to human health, society, and ecological systems. Progress insimulating subsurface performance of a potential disposal site requires improved understandingof geological processes and the effective integration of high-resolution geophysicalmeasurements into model development and parameterization. In addition, to fully integratecharacterization and modeling will require advances in methods for joint inversion of coupledprocess models that contain important nonlinearities, scale effects, and uncertainties.Advanced monitoring approaches are needed to improve our understanding of subsurface systemresponses to large-scale manipulations and to detect releases associated with the manipulationsthat may pose a risk to living organisms and earth systems. Scientific advances in the integrationof disparate monitoring datasets and in the coupling of monitoring and modeling approaches areexpected to lead to an unprecedented ability to quantify and predict subsurface systemtransformations associated with large-scale anthropogenic manipulations over relevant spatialscales and over decadal to century time frames. Technological advances will include thedevelopment of systems that can be routinely used to detect and quantify phenomena thatprovide the earliest indication of anomalous responses that may portend impending failure of amanipulated system.EXECUTIVE SUMMARYModeling practices in geosciences currently deal with variations in length scales (from atoms toplanets), variations in observable data, and variations in physical, chemical and hydrologicalconstitutive relationships, in a piecemeal, ad hoc and disparate manner. If significant progress isto be made in understanding reservoir-scale geological systems and predicting the behavior ofthese systems under anthropogenic perturbations, then forward and inverse modeling mustintegrate across scales, data types, and geological processes. Increasingly large and disparatedata streams need to be incorporated into modeling systems in a comprehensive and adaptiveway. Furthermore, new techniques are needed to quantify uncertainty in model predictions andconclusions that arise from data limitations, modeling approximations, and non-uniqueness.The datasets that must be integrated for large-scale, complex geologic systems come from acombination of local measurements and remote sensing techniques. Subsequent monitoringapproaches will be based on repetitive collection of similar data. Hence, characterization of thesubsurface, modeling of processes occurring there, and monitoring of these processes areinextricably linked. The basic science challenges involve developing improved theoretical,mathematical and computational approaches for using multiple hydrological, geochemical,Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systems 79