QRC members lead and participate in a wide range of disciplinary and interdisciplinary research projects from the study of past earth climates and glaciations to shifts in the geographic distributions and evolution of vegetation and faunal communities, to the evolution and dispersals of the genus Homo and the increasing scales of human modification of earth environments through the Holocene. QRC provides a venue for meeting and collaborating with scholars across Quaternary disciplines. We are also fortunate to be able to provide seed funding and small grants for member research projects. We are especially happy to support grad student and junior scholar research activities, much of which leads to larger, external funding from agencies like the National Science Foundation.
A search for pre-LGM megaflood sedimentation in Cascadia Basin
Abstract: Marine sediments along the Cascadia margin are likely to contain continuous, long-term records of marine and continental change in the Pacific Northwest over the last several million years. While glaciations, floods, and erosion have reworked the terrestrial record, many marine sites had continuous deposition over this timespan. Such sites are potential archives of oceanographic history, meltwater influx, density-current processes, subduction zone tectonics, and landscape evolution. We propose to study two legacy sediment cores from Cascadia Basin, focusing on depositional chronology and tracers of sediment provenance. The two cores, Deep Sea Drilling Program (DSDP) Sites 174 and 175 are by far the deepest cores from this region, and thus unique in their recovery of sediment spanning multiple glacial-interglacial cycles. This work is a first step towards finding and developing long-term records of megafloods down the Columbia River and understanding Cascadia Basin sedimentation throughout the Pleistocene.
Quantifying bed material abrasion to help predict the response of rivers to pulses of sediment supply
Abstract: Deglaciating alpine catchments represent ideal natural experiments, with large recurring pulses of sediment contributed to the fluvial network from isolated, identifiable source regions. These sediment pulses substantially alter channel morphology on decadal timescales. Taking advantage of this fact, I am working to model the response of basins with varying lithologies to pulses of glaciogenic sediment. I am doing so by combining glaciohydrologic and river channel morphodynamic models, initiated and driven by morphologic data gathered from remote sensing observations, and tested with field measurements of river bed material grain size and lithology. Key hypothesis: Where glaciers carve especially friable bedrock (such as the headwaters of the Suiattle River), sediment supply perturbations due to deglaciation will transit downstream with the magnitude of morphologic effects decreasing dramatically with distance from the source due to bedload abrasion.
Transient river response to headwater deglaciation, Mount Rainier, WA
Abstract: This work seeks to test an idea counter to conventional wisdom regarding the nature and magnitude of glacial fluxes and their role with respect to downstream landform development (e.g., glaciofluvial fans and terraces) as well as climatic oscillations on the timing of landscape evolution (i.e., aggradation versus degradation). Glaciogenic sediment is stored in large moraine complexes built by dynamic alpine glaciers and released when ice retreat debutresses the unstable landforms. Paraglacial sedimentation following deglaciation is the process yet meltwater hydrology is often invoked as the driver of alpine landscape evolution but for unknown durations, with little consideration of flux characteristics (i.e., melt, runoff, and sediments), and with unknown lag times. Little quantitative, mechanistic knowledge exists regarding the processes, controls, timing, and duration of paraglacial sedimentation. By comparing two major glacier-fed rivers at Mount Rainier, WA, this study proposes to elucidate whether meltwater discharge or available glaciogenic sediment fluxes drive downstream transient landform development/degradation through a combination of topographic survey methods, historic discharge and photograph analysis for river response, as well as geophysical methods to quantify sediment supply and storage characteristics. Preliminary data collected in September 2015 from a fixed-wing aircraft for Structure-from-Motion will function as a basemap for geomorphic change detection as well as quantitative rates of change.
Rates and mechanisms of bedrock incision and strath terrace formation in a forested catchment, West Fork Teanaway River, Cascade Range, Washington
Abstract: Rivers incise bedrock, setting the tempo for landscape development, through periods of incision and incisional hiatuses. While many theoretical and experimental efforts have sought to understand the controls on bedrock incision and the evolution of bedrock channel shape, questions regarding the processes and controls on vertical and lateral bedrock erosion are informed by relatively few direct field measurements. To better understand rates, controls, and mechanisms of lateral and vertical bedrock incision by rivers, we measured bedrock bed and bank incision and mapped and radiocarbon-dated strath terraces in the West Fork Teanaway River. The West Fork drains 102 km2 of the tectonically quiescent southeastern North Cascade Range of Washington, and, in its lower 3 river kilometers, is rapidly incising its bed and creating strath terraces.
Report: Read the published article for this project here.
Large wood debris and logjam dynamics during and after the Elwha River Restoration project
Abstract: Woody debris is a primary control on river morphodynamics, affecting sediment transport, streambed morphology, fluid flow and physical habitat. Dam removals have become an increasingly used tool in river management for restoring ecosystem function and natural river processes. The Elwha River Restoration project dam removals are a unique opportunity to investigate the effects of increased wood and sediment supply on woody debris dynamics and streambed morphology. Developing a quantitative understanding of how wood interacts with water and sediment to influence geomorphology and aquatic habitat remains a key challenge for river management, environmental engineering, ecology and geoscience in forested regions. Despite advances in the understanding of wood in rivers, fundamental questions remain about wood mobility, logjam dynamics and geomorphology, and their response to changes in wood, water and sediment supply. This research investigates the effects of the Elwha River Restoration project dam removals on woody debris dynamics and streambed morphology.
Abstract: Woody debris is a primary control on river morphodynamics, affecting sediment transport, streambed morphology, fluid flow and physical habitat. Dam removals have become an increasingly used tool in river management for restoring ecosystem function and natural river processes. The Elwha River Restoration project dam removals are a unique opportunity to investigate the effects of increased wood and sediment supply on woody debris dynamics and streambed morphology. Developing a quantitative understanding of how wood interacts with water and sediment to influence geomorphology and aquatic habitat remains a key challenge for river management, environmental engineering, ecology and geoscience in forested regions. Despite advances in the understanding of wood in rivers, fundamental questions remain about wood mobility, logjam dynamics and geomorphology, and their response to changes in wood, water and sediment supply. This research investigates the effects of the Elwha River Restoration project dam removals on woody debris dynamics and streambed morphology.