Earth Surface Dynamics Research Articles

Digitizing the Sedimentary Record: Efficient Data Structures for Dynamic Stratigraphy

As the surface of the Earth evolves over geologic time sediment is transported from high mountains to low lying sedimentary basins, accumulating stratigraphy which stores a sedimentary record of past environments. Understanding the structure of this stratigraphy is essential for exploiting sub-surface resources such as oil and water, and for deciphering the sedimentary record. Sophisticated computational models of Earth-surface dynamics can be used to predict formation of stratigraphy, but require stratigraphy in a discrete form. Here I present a discrete stratigraphic data structure which enables simulation of dynamic stratigraphic evolution. The data structure is robust and efficient, but can be easily coupled to existing Earth-surface dynamics models with minimal effort due to a simple interface. This represents a significant advance which will allow widespread use of dynamic models to predict and invert stratigraphy for application in a variety of fields.

Fluvial Landscapes and Stratigraphy in a Flume

We use data from an experiment conducted in the Experimental EarthScape (XES) facility, National Center for Earth-surface Dynamics (NCED), St.Anthony Falls Laboratory (SAFL), University of Minnesota, to demonstrate why incised valleys preserved in the stratigraphic record probably bear little resemblance to the actual valleys as they appeared in the paleolandscape. In an experiment designed to study fluvial response to changes in sea level,we find that preserved incised-valley structures are typically broader and have more gentle side slopes, than the topographic features from which they develop. Also, because of widening driven by valley wall erosion during both relative sea-level rise and fall, there is virtually no remnant of terraces formed during falling relative sea level preserved in the stratigraphic record.The process of filling an incised valley due to rising relative sea level is not a passive depositional process that simply buries and preserves the original shape of the valley; rather, it includes an energetic erosional component that substantially reshapes the original valley form.

Introduction to special section on Hydrologic Synthesis

The Hydrological Synthesis special section presents synthesis topics that have the potential to revolutionize hydrological sciences in a manner needed to meet critical water challenges that we now face. The special section also highlights topics that are important and exciting enough to compel researchers to engage in collaborative synthesis activities. This introductory paper provides a brief overview of nine papers that are included in this special section, which discuss the synthesis of tools, data, concepts, theories, or approaches across disciplines and scales. The wide range of topics that are explored include groundwater quality, river restoration, water management, nitrogen cycling, and Earth surface dynamics. Collectively, the special section papers illustrate that the challenge to deal effectively with complex water problems is not purely a scientific, technological, or socioeconomic one; it is instead a complex, 21st century problem that requires coordinated synthesis.

Toward a unified science of the Earth's surface: Opportunities for synthesis among hydrology, geomorphology, geochemistry, and ecology

The Earth's surface is shaped by the interaction of tectonics, water, sediment, solutes, and biota over a wide range of spatial and temporal scales and across diverse environments. Development of a predictive science of Earth surface dynamics integrates many disciplines and approaches, including hydrology, geomorphology, ocean and atmospheric science, sedimentary and structural geology, geochemistry, and ecology. This paper discusses challenges, opportunities, and a few example problems that can serve as pathways toward this integration.