Russell S. Harmon

Magmatic history and evolution of the Central American Land Bridge in Panama since Cretaceous times

Chemical compositions for 310 igneous rocks from the Cordillera de Panama and the Sona and Azuero peninsulas were supplemented by 40 Ar/ 39 Ar dating and Sr-, Nd-, Pb-, and O-isotope analysis to determine the magmatic evolution and oceanic plate interactions over the past 100 Ma in western Panama. An initial phase of intraplate magmatism, having geochemical characteristics of the Galapagos hotspot, formed the oceanic basement of the Caribbean large igneous province from 139 to 69 Ma. Younger accreted terranes with enriched trace element patterns (accreted ocean island basalt [OIB]) were amalgamated between 70 and 20 Ma. A second magmatic phase in the Azuero and Sona peninsulas has trace element patterns (Sona-Azuero arc) suggesting the initiation of subduction at 71–69 Ma. Arc magmatism continued in the Chagres basin region (Chagres-Bayano arc) from 68 to 40 Ma. A third phase formed discrete volcanic centers across the Cordillera de Panama (Cordilleran arc) from 19 to 5 Ma. The youngest phase consists of isolated volcanic centers of adakitic composition (Adakite suite) in the Cordillera de Panama that developed over the past 2 million years. Initiation of arc magmatism at 71 Ma coincides with the cessation of Galapagos plateau formation, suggesting a causal link. The transition from intraplate to arc magmatism occurred relatively quickly and introduced a new enriched mantle source. The arc magmatism involved progressive transition to more homogeneous intermediate mantle wedge compositions through mixing and homogenization of subarc magma sources through time and/or the replacement of the mantle wedge by a homogeneous, relatively undeleted asthenospheric mantle. Adakite volcanism started after a magmatic gap, enabled by the formation of a slab window.

Landscape erosion and evolution modeling

Preface. Acknowledgements. Contributors. 1. Introduction to Soil Erosion and Landscape Evolution Modeling. 2. Erosion Problems on U.S. Army Training Lands. 3. Effects of Freeze-Thaw Cycling on Soil Erosion. 4. Determination of Slope Displacement Mechanisms and Causes. 5. Using Cosmogenic Nuclide Measurements in Sediments to Understand Background Rates of Erosion and Sediment Transport. 6. Erosion Modelling. 7. The Water Erosion Prediction Project (WEPP) Model. 8. A Simulation Model for Erosion and Sediment Yield at the Hillslope Scale. 9. Waterbots. 10. Two-Dimensional Watershed-Scale Erosion Modeling with CASC2D. 11. Multiscale Soil Erosion Simulations for Land Use Management. 12. The Channel-Hillslope Integrated Landscape Development Model (CHILD). 13. Simulation of Streambank Erosion Processes with a Two-Dimensional Numerical Model. 14. Spatial Analysis of Erosion Conservation Measures with LISEM. 15. Numerical Simulation of Sediment Yield, Storage, and Channel Bed Adjustments. 16. The Limits of Erosion Modeling. 17. Envisioning a Future Framework for Managing Land and Water Resources. Index.

Advanced Concepts on Remote Sensing of Precipitation at Multiple Scales

ADVANCED CONCEPTS ON REMOTE SENSING OF PRECIPITATION AT MULTIPLE SCALES by S oroosh S orooshian , A mir A gha K ouchak , P hillip A rkin , J ohn E ylander , E fi F oufoula -G eorgiou , R ussell H armon , J an M. H. H endrickx , B isher I mam , R obert K uligowski , B rian S kahill , and G ail S kofronick -J ackson Overview of Recommendations (i) Uncertainty of merged products and multisensor observations warrants a great deal of research. Quantification of uncertainties and their propa- gation into combined products is vital for future development. (ii) Future improvements in satellite-based precipi- tation retrieval algorithms will rely on more in- depth research on error properties in different climate regions, storm regimes, surface condi- tions, seasons, and altitudes. Given such infor- mation, precipitation algorithms for retrieval, AFFILIATIONS : S orooshian , A gha K ouchak , I mam —University of California, Irvine, Irvine, California; A rkin —University of Maryland, College Park, Maryland; E ylander —U.S. Army Engineer Research and Development Center, Hanover, New Hampshire; F oufoula -G eorgiou —University of Minnesota, Minneapolis, Minnesota; H armon —Army Research Laboratory, Durham, North Carolina; H endrickx —New Mexico Tech, Socorro, New Mexico; K uligowski —NOAA/NESDIS/ STAR, Camp Springs, Maryland; S kahill —U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi; S kofronick -J ackson —NASA GSFC, Greenbelt, Maryland CORRESPONDING AUTHOR : Soroosh Sorooshian, Department of Civil & Environmental Engineering, University of California, Irvine, Irvine, CA 92697 E-mail: soroosh@uci.edu DOI:10.1175/2011BAMS3158.1 In final form 18 April 2011

Laser-induced breakdown spectroscopy-based geochemical fingerprinting for the rapid analysis and discrimination of minerals: the example of garnet

Laser-induced breakdown spectroscopy (LIBS) is an analytical technique real-time geochemical analysis that is being developed for portable use outside of the laboratory. In this study, statistical signal processing and classification techniques were applied to single-shot, broadband LIBS spectra, comprising measured plasma light intensities between 200 and 960 nm, for a suite of 157 garnets of different composition from 92 locations worldwide. Partial least squares discriminant analysis was applied to sets of 25 LIBS spectra for each garnet sample and used to classify the garnet samples based on composition and geographic origin. Careful consideration was given to the cross-validation procedure to ensure that the classification algorithm is robust to unseen data. The results indicate that broadband LIBS analysis can be used to discriminate garnets of different composition and has the potential to discern geographic origin.

Real-time landscape model interaction using a tangible geospatial modeling environment

Emerging technologies that combine the flexibility of digital landscape representation with easy-to-interpret 3D physical models open new possibilities for user interaction with geospatial data. A prototype tangible geospatial modeling environment lets users interact with landscape analysis and simulations using a tangible physical model. We introduce a concept that builds upon previous independent tangible user interface (TUI) and terrain analysis research and aims at more intuitive collaborative interaction with digital landscape data

Modeling and analysis of landscape evolution using airborne, terrestrial, and laboratory laser scanning

Current laser scanning (Lidar, light detection and ranging) technologies span a wide range of survey extent and resolutions, from regional airborne Lidar mapping and terrestrial Lidar field surveys to laboratory systems utilizing indoor three-dimensional (3D) laser scanners. Proliferation in Lidar technology and data collection enables new approaches for monitoring and analysis of landscape evolution. For example, repeat Lidar surveys that generate a time series of point cloud data provide an opportunity to transition from traditional, static representations of topography to terrain abstraction as a 3D dynamic layer. Three case studies are presented to illustrate novel techniques for landscape evolution analysis based on time series of Lidar data: (1) application of multiyear airborne Lidar surveys to a study of a dynamic coastal region, where the change is driven by eolian sediment transport, wave-induced beach erosion, and human intervention; (2) monitoring of vegetation growth and the impact of landscape structure on overland flow in an agricultural field using terrestrial laser scanning; and (3) investigation of landscape design impacts on overland water flow and other physical processes using a tangible geospatial modeling system. The presented studies demonstrate new insights into landscape evolution in different environments that can be gained from Lidar scanning spanning 1.0–0.001 m resolutions with geographic information system analysis capabilities.

Advancing the remote sensing of precipitation

Author(s): Sorooshian, S; Aghakouchak, A; Arkin, P; Eylander, J; Foufoula-Georgiou, E; Harmon, R; Hendrickx, JMH; Imam, B; Kuligowski, R; Skahill, B; Skofronick-Jackson, G | Abstract: Satellite-based global precipitation data has addressed the limitations of rain gauges and weather radar systems in forecasting applications and for weather and climate studies. Inspite of this ability, a number of issues that require the development of advanced concepts to address key challenges in satellite-based observations of precipitation were identified during the Advanced Concepts Workshop on Remote Sensing of Precipitation at Multiple Scales at the University of California. These include quantification of uncertainties of individual sensors and their propagation into multisensor products warrants a great deal of research. The development of metrics for validation and uncertainty analysis are of great importance. Bias removal, particularly probability distribution function (PDF)-based adjustment, deserves more in-depth research. Development of a near-real-time probabilistic uncertainty model for satellitebased precipitation estimates is highly desirable.

Case studies of scenario analysis for adaptive management of natural resource and infrastructure systems

Management of natural resources and infrastructure systems for sustainability is complicated by uncertainties in the human and natural environment. Moreover, decisions are further complicated by contradictory views, values, and concerns that are rarely made explicit. Scenario analysis can play a major role in addressing the challenges of sustainability management, especially the core question of how to scan the future in a structured, integrated, participatory, and policy-relevant manner. In a context of systems engineering, scenario analysis can provide an integrated and timely understanding of emergent conditions and help to avoid regret and belated action. The purpose of this paper is to present several case studies in natural resources and infrastructure systems management where scenario analysis has been used to aide decision making under uncertainty. The case studies include several resource and infrastructure systems: (1) water resources (2) land-use corridors (3) energy infrastructure, and (4) coastal climate change adaptation. The case studies emphasize a participatory approach, where scenario analysis becomes a means of incorporating diverse stakeholder concerns and experience. This approach to scenario analysis provides insight into both high-performing and robust initiatives/policies, and, perhaps more importantly, influential scenarios. Identifying the scenarios that are most influential to policy making helps to direct further investigative analysis, modeling, and data-collection efforts to support the learning process that is emphasized in adaptive management.

3.9 GIS-Based Soil Erosion Modeling

This chapter explains the theory and methods for GIS-based modeling of soil erosion, sediment transport, and deposition by surface water flow. The mathematical foundations of erosion models are introduced and simplified equations, suitable for GIS implementation, are derived. The presented methods cover modeling of hillslope erosion and deposition, gully formation, and landscape evolution processes. Coupling of erosion models with GIS is discussed, followed by examples of GIS implementation of simple and advanced models. The concepts and methods are illustrated using two case studies, that focus on feedbacks between the human activity and landscape processes.

Advanced Signal Processing Analysis of Laser-Induced Breakdown Spectroscopy Data for the Discrimination of Obsidian Sources

Obsidian is a natural glass of volcanic origin and a primary resource used by indigenous peoples across North America for making tools. Geochemical studies of obsidian enhance understanding of artifact production and procurement and remain a priority activity within the archaeological community. Laser-induced breakdown spectroscopy (LIBS) is an analytical technique being examined as a means for identifying obsidian from different sources on the basis of its geochemical fingerprint. This study tested whether two major California obsidian centers could be distinguished from other obsidian localities and the extent to which subsources could be recognized within each of these centers. LIBS data sets were collected in two different spectral bands (350±130 nm and 690±115 nm) using a Nd:YAG 1064 nm laser operated at ~23 mJ, a Czerny-Turner spectrograph with 0.2-0.3 nm spectral resolution and a high performance imaging charge couple device (ICCD) detector. Classification of the samples was performed using partial least-squares discriminant analysis (PLSDA), a common chemometric technique for performing statistical regression on high-dimensional data. Discrimination of samples from the Coso Volcanic Field, Bodie Hills, and other major obsidian areas in north-central California was possible with an accuracy of greater than 90% using either spectral band.