The group of scientists that make up the Intergovernmental Panel on Climate Change found in 2007 that the warming of Earth’s climate is unequivocal and largely due to human activity. Earth’s climate has changed in the past, though the recent magnitude and pace of changes are unprecedented in human existence....
This project defined criteria to allow only the use of existing spatial databases (and only those with comprehensive coverage of the ecoregion) to identify the HGM (hydrogeomorphic) class of mapped Willamette Ecoregion wetlands. The project then applied those criteria automatically and systematically to every mapped wetland in the ecoregion, resulting...
In a series of Willamette Valley wetlands, standardized protocols were used in 2009 and 2010 to primarily assess (a) vegetation species composition and (b) relative levels of ecosystem services. Of the 60 wetlands visited in one or both years, 34 were classified as riverine and 26 as flats. Of the...
This document partially addresses the Wetlands component of San Juan County’s Critical Areas Ordinance (CAO). Drawing from a foundation in best available science, it describes important functions performed by the County's wetlands, effects of various activities on those functions, and strategies for protecting wetland functions from impacting activities, with an...
This document provides definitions and a general overview of streams and lakes of San Juan County (SJC) and then describes impacts to these water bodies and strategies for determining widths of buffers that protect their functions. It similarly provides definitions and a general overview of SJC upland (terrestrial) habitats, describes...
Oregon is in the midst of major changes to the way it manages use of the ocean off its shores. Consideration for all stakeholder groups will contribute to defensible decisions regarding the use of ocean and coastal resources. This relies on an understanding of the various stakeholders in ocean resources,...
An integral component to understanding lithospheric rheology, fault mechanics, and geodynamic processes is knowledge of the subsurface thermal regime. This study presents thermal data from 26 new borehole sites drilled during the installation of borehole strain meters as part of the Plate Boundary Observatory (PBO). These data extends existing coverage...
Documented trends in rising sea levels, storminess, and extreme wave heights have the potential to increase the frequency and magnitude of coastal change hazards, increasing risks to coastal infrastructure and environmental resources. Coastal planners and decision makers need information about the impacts of future hazards in order to apply mitigation...
Deep-sea bamboo coral (Isidella sp.) SE000901A from the southern Oregon coast (water depth 1048m) provides a high-resolution record of variability of North Pacific Intermediate Water (NPIW) and carbon rain to the sea floor, related to coastal upwelling, from 1808 to 2000AD. Counting of annual layers in magnesium to calcium (Mg/Ca)...
The volcanic origin of the Samoan archipelago can be explained by one of three models, specifically, by a hot spot forming over a mantle plume, by lithospheric extension resulting from complex subduction tectonics in the region, or by a combination of these two processes, either acting sequentially or synchronously. In...
This study investigated long-term (1961-2008) changes in albacore (Thunnus alalunga) abundance and distribution in relation to local environmental and large-scale climate indices in the Northeastern Pacific using time series and spatial analyses. Prior to the time series analysis, a wavelet analysis was conducted to examine nonrandom patterns of cyclical variability...
The marine and freshwater fishery resources of West Africa are some of the most productive in the world, and hold vast potential to provide economic prosperity and food security for the developing nations of that region. Nevertheless, the realized social benefits from fishery resources to West African nations have fallen...
In this study we present 42 new ⁴⁰Ar/³⁹Ar incremental heating age determinations updated age progression for the Louisville seamount trail. Louisville is the South Hawaiian‐Emperor seamount trail, both trails representing intraplate volcanism (~80 Ma to present) and being examples of primary hot spot lineaments. Our age‐progressive trend from 71 to...
Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth's climate system to external and internal forcings. During this interval of global warming, the decay of...
The thermodynamic history of the Earth is preserved in the trace element record created through igneous processes. The ability to interpret that record depends on the accuracy and precision of numerical models that connect igneous processes with their geochemical consequences. This project answers three major questions concerning the relationship between...
The quantification and description of sea surface temperature (SST) is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change. Recent research indicates that there has been a warming trend in ocean temperatures over the last...
For the west coast of North America, from northern California to southern Washington, a habitat suitability prediction framework was developed to support wave energy device siting. Concern that wave energy devices may impact the seafloor and benthos has renewed research interest in the distribution of marine benthic invertebrates and factors...
Climate changes in the Pacific Northwest, USA, may cause both retreat of alpine glaciers and increases in the frequency and magnitude of storms delivering rainfall at high elevations absent significant snowpack, and both of these changes may affect the frequency and severity of destructive debris flows initiating on the region's...
An approach to climate change feedback analysis is described in which tropospheric relative humidity replaces specific humidity as the state variable that, along with the temperature structure, surface albedos, and clouds, controls the magnitude of the response of global mean surface temperature to a radiative forcing. Despite being simply a...
Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but...
Variable ocean conditions can greatly impact lower trophic level prey assemblages in marine ecosystems, with effects propagating up to higher trophic levels. Our goal was to better understand how varying ocean conditions influence diets and niche overlap among a suite of low- to mid trophic level predators. We studied the...
Pesticides are widely used to control undesirable pests and may be applied directly to water or lands directly adjacent to water. There can be unintended consequences, however, to native, threatened, and endangered species. There is little information on the impacts of aquatic pesticides and best management practices (BMPs) to NOAA...
The neon isotope compositions of basalts from the Northwest Lau Back-arc Basin reflect three-component mixing between an ocean island basalt (OIB) mantle hotspot component, mid-ocean ridge basalt (MORB) mantle, and atmosphere. Our study confirms that a mantle hotspot signature is present in the neon isotopes of both the Rochambeau Rifts...
Basal melting of ice shelves around Antarctica contributes to formation of Antarctic Bottom Water and can affect global sea level by altering the offshore flow of grounded ice streams and glaciers. Tides influence ice shelf basal melt rate (w(b)) by contributing to ocean mixing and mean circulation as well as...
We determine rates of gross photosynthetic O₂ production (GOP) and net community O₂ production (NCP) using the triple oxygen isotope and O₂/Ar approach on two spring and two late summer meridional transects of the NE Pacific. Observed GOP and NCP in the subtropical (89 ± 9 and 8.3 ± 1.3...
Four multicyclic complex calderas and smaller ignimbrite shields located within the Altiplano Puna Volcanic Complex of the Central Andes (APVC) erupted 13000 km³ of magma within the last 11 Ma. One of the largest and most complex of these is the Cerro Guacha Caldera. Ar-Ar age determinations and paleomagnetic directions...
We report a decadally resolved record of atmospheric CO₂ concentration for the last 1000 years, obtained from the West Antarctic Ice Sheet (WAIS) Divide shallow ice core. The most prominent feature of the pre-industrial period is a rapid ∼7 ppm decrease of CO₂ in a span of ∼20–50 years at...
The purpose of Oregon's Nearshore Research Inventory (NRI) project was to inventory and map the current and future use of Oregon's nearshore environment by the scientific research community for use in Oregon's marine spatial planning process. Spatial and qualitative data on the use of Oregon's ocean and coast by the...
Parks help to build social cohesion within a community. Urban open spaces offer
a sense of place, act as the focal points for public gatherings, and provide an
opportunity for social networking (Francis, 2003; Hayward, 1989). While offering so
much they are also known to be places of disgust and...
Declines or extinctions of the native intertidal estuary blue mud shrimp, Upogebia pugettensis, have been observed or are suspected in all of its populations over the species’ range. These declines are associated with the introduced Asian bopyrid isopod parasite, Orthione griffenis, which effectively castrates females. Baseline estimates of population abundances...
Kelvin-Helmholtz (KH) instability, characterized by the distinctive finite-amplitude billows it generates, is an important mechanism in the development of turbulence in the stratified interior of the ocean. In particular, it is often assumed that the onset of turbulence in internal waves begins in this way. Clear recognition of the importance...
Vegetation at the aquatic–terrestrial interface can alter landscape features through its growth and interactions with sediment and fluids. Even similar species may impart different effects due to variation in their interactions and feedbacks with the environment. Consequently, replacement of one engineering species by another can cause significant change in the...
Better fisheries management is often given as one justification for research on improving forecasts of fish survival. However, the value gained from expected improvements in forecast skill in terms of achieving management goals is rarely quantified as part of research objectives. Using Monte Carlo simulations of population dynamics, we assessed...
Weak-wind flow in the nocturnal boundary is one of the most poorly understood problems in the field of meteorology. The understanding of weak-wind flows is essential for the improvement of regulatory dispersion models which are currently rendered invalid under weak-wind conditions and stable stratification. Recently there have been increased efforts...
Montane meadows comprise less than 5% of the landscape of the western Cascades of Oregon, but they provide habitat for diverse species of plants and pollinators. Little is known about plant-pollinator network structure at these sites. This study quantified plant-pollinator interactions over the summer of 2011, based on six observations...
Ever expanding pressures on the health and productivity of our oceans and coasts from threats such as coastal development and climate change are stressing the need to consider the full spectrum of factors, scales, datasets, opinions, and trade-offs for current and future coastal management actions (Guerry 2009; McLeod and Leslie...
Oregon's ocean waters are a potential source of wind, wave, and tidal energy; of interest to renewable energy entrepreneurs and to the U.S. government as it seeks to bolster energy security. In order to install technology to capture this energy, however, it may be necessary to mitigate conflict with existing...
The Altiplano-Puna Volcanic Complex in the Central Andes is one of the youngest large silicic volcanic fields (LSVFs) in the world, erupting over 13,000 km³ of material during multiple supereruptions from 11 to 1 Ma. Understanding the timescales over which magma is stored in the crust prior to eruption is...
This study developed a strategic conservation project for the Oregon Coast Aquarium in Newport, Oregon focusing on a signature species and this aquarium’s conservation focus areas (i.e., marine debris, sustainable fisheries, water quality, climate change). This study also examined the potential for incorporating an ecotourism or wildlife tourism component to...
The rapid increase in atmospheric carbon dioxide (CO₂) over the last 250 years has led to the absorption of approximately 550 billion tons of anthropogenic CO₂ by the global ocean. This oceanic uptake of CO₂ has resulted in decreasing pH and alterations to carbonate chemistry, threatening many ecologically and economically...
The variation of the sea surface sensible heat flux is investigated using data from the Gulf of Tehuantepec Experiment (GOTEX) and from eight additional aircraft datasets representing a variety of surface conditions. This analysis focuses on near-neutral conditions because these conditions are common over the sea and are normally neglected,...
River basins provide essential services for both humans and ecosystems. Understanding the connections between ecosystems and society and their function has been at the heart of resilience studies and has become an increasing important endeavor in research and practice. In this dissertation, I define basin resilience as a river basin...
Pacific cod (Gadus macrocephalus) is an important species, both economically and ecologically in the Bering Sea and Aleutian Islands (BSAI). However, little is known about its spawning dynamics. To address this knowledge gap, I developed a gross anatomical maturity key for Pacific cod to assess temporal and spatial patterns of...
Silicic volcanism in the central Oregon Cascade range has decreased in both the size and frequency of eruptions from its initiation at ~40 Ma to present. The reasons for this reduction in silicic volcanism are poorly constrained. Studies of the petrogenesis of these magmas have the potential for addressing this...
On January 11, 2011, the Pacific Fishery Management Council (PFMC) instituted a catch
share program for the West Coast groundfish trawl fishery. The program was intended to
create a more sustainable fishery and increase economic efficiency through the use of
individual fishing quotas and fishing cooperatives. While there are extensive...
The debate over a coastal migration route for the First Americans revolves around two major points: seafaring technology, and a viable landscape and resource base. Three lake cores from Sanak Island in the western Gulf of Alaska yield the first radiocarbon ages from the continental shelf of the Northeast Pacific...
In this thesis I present the results of a comprehensive assessment of the Pacific-North American (PNA) teleconnection pattern in general circulation models (GCMs) and a regional climate model (RCM). The PNA teleconnection pattern is a quasi-stationary wave field over the North Pacific and North America that has long been recognized...
Nearshore hypoxia within the Northern California Current (NCC) system is a seasonal phenomenon caused by coastal upwelling and occurs mainly during late-summer and early fall. The effects of low oxygen levels on fish and invertebrate communities, particularly during early-life history stages, however, are poorly known for this area. I investigated...
The spawning habitats of many large marine pelagic predators are poorly known. This lack of knowledge hampers conservation efforts that are aimed at identifying critical habitats for the spawning of these species. We hypothesized that phylogenetically related species show different adaptations and respond differently to environmental and geographical cues for...
As a quantitative test of moored mixing measurements using [subscript χ]pods, a comparison experiment was conducted at 0°, 140°W in October–November 2008. The following three measurement elements were involved: (i) NOAA’s Tropical Atmosphere Ocean (TAO) mooring with five [subscript χ]pods, (ii) a similar mooring 9 km away with seven [subscript...
Sensor design and mission planning for satellite ocean color measurements requires careful consideration of the signal dynamic range and sensitivity (specifically here signal-to-noise ratio or SNR) so that small changes of ocean properties (e.g., surface chlorophyll-a concentrations or Chl) can be quantified while most measurements are not saturated. Past and...
A wave-structure interaction model is implemented, and power output estimates are made for a simplified wave energy converter operating in measured spectral wave conditions. In order to estimate power output from a wave energy converter, device response to hydrodynamic forces is computed using a boundary element method potential flow model....
Interannual variability of Humboldt squid (Dosidicus gigas) occurrence in the northern California Current System is largely unknown. In Oregon, the distribution of this versatile predator and what is influencing their range expansion from Mexico is poorly understood due to the recent nature of their "invasion" and a lack of monitoring....
With the continued and unprecedented decline of coral reefs worldwide, evaluating the factors that contribute to coral demise is of critical importance. As coral cover declines, macroalgae are becoming more common on tropical reefs. Interactions between these macroalgae and corals may alter the coral microbiome, which is thought to play...
Radiative feedbacks associated with changes in water vapor, temperature, surface albedo and clouds remain a major source of uncertainty in our understanding of climate's response to anthropogenic forcing. In this dissertation climate model data is used to investigate variations in feedbacks that result from changing CO₂ forcing and the time...
Understanding and modeling microbial responses and feedbacks to climate change is hampered by a lack of a framework in the pelagic environment by which to link local mechanism to large scale patterns. Where terrestrial ecology draws from landscape theory and practice to address issues of scale, the pelagic seascape concept...
Flow and temperature are strongly linked environmental factors driving ecosystem processes in streams. Stream temperature maxima (T [subscript max_w]) and stream flow minima (Q[subscript min]) can create periods of stress for aquatic organisms. In mountainous areas, such as western North America, recent shifts toward an earlier spring peak flow and...
Density-independent and density-dependent variables both affect the spatial distributions of species. However, their effects are often separately addressed using different analytical techniques. We apply a spatially explicit regression framework that incorporates localized, interactive and threshold effects of both density-independent (water temperature) and density-dependent (population abundance) variables, to study the spatial...
Understanding groundwater conditions in the upland parts of volcanic island aquifers is critical for sustainable groundwater development in these resource-limited environments. Yet groundwater conditions in such settings are generally difficult to characterize because of sparse well drilling (high cost and/or limited access). Information needed for resource evaluation includes upland depth...
During the last glacial period atmospheric carbon dioxide and temperature in Antarctica varied in a similar fashion on millennial time scales, but previous work indicates that these changes were gradual. In a detailed analysis of one event we now find that approximately half of the CO₂ increase that occurred during...
As competing uses of our coastlines increase, natural resource agencies are employing marine spatial planning (MSP) to designate areas for different uses or activities in order to reduce conflicts while achieving ecological, economic and social objectives. A central challenge of implementing MSP is development of a rigorous approach for analyzing...
A method is presented for estimating bathymetry in a river, based on observations of depth-averaged velocity during steady flow. The estimator minimizes a cost function that combines known information in the form of a prior estimate and measured data (including measurement noise). State augmentation is used to relate the measured...
Interaction between mixed layer baroclinic eddies and small-scale turbulence is studied using a nonhydrostatic large-eddy simulation (LES) model. Free, unforced flow evolution is considered, for a standard initialization consisting of an 80-m-deep mixed layer with a superposed warm filament and two frontal interfaces in geostrophic balance, on a model domain...
The Kane Oceanic Core Complex (OCC) is a valuable window into crustal architecture and chemical composition of the lithosphere beneath a slow-spreading ocean ridge. A suite of > 30 samples (comprised of whole rocks, mineral separates and basalt glasses) has been analyzed for ³He/⁴He isotope ratios and He concentrations. Gas...
The daytime evolution of warm cloud microphysical properties over the southeast Pacific during October–November 2008 is investigated with optical/infrared retrievals from the Tenth Geostationary Operational Environmental Satellite (GOES-10) imager. GOES-10 retrievals, produced at NASA Langley Research Center, are validated against in situ aircraft observations and with independent satellite observations. Comparisons...
Most authigenic carbonates previously recovered from the Cascadia slope have Sr-⁸⁷/Sr-⁸⁶ signatures that reflect shallow precipitation in equilibrium with coeval seawater. There is also evidence for carbonate formation supported by fluids that have been modified by reactions with the incoming Juan de Fuca plate (Sr-⁸⁷/⁸⁶(Sr) = 0.7071; Teichert et al.,...
Packets of nonlinear internal waves (NLIWs) in a small area of the Mid-Atlantic Bight were 10 times more energetic during a local neap tide than during the preceding spring tide. This counterintuitive result cannot be explained if the waves are generated near the shelf break by the local barotropic tide...
The influence of mesoscale ocean eddies on near-surface ocean temperature, surface stress and phytoplankton communities is investigated by collocating numerous satellite measurements along with vertical profiles of oceanic temperature and salinity to the interiors of eddies identified and tracked in altimetric sea surface height maps.
The surface currents associated with...
The Franciscan Complex accretionary prism was assembled during an similar to 165-m.y.-long period of subduction of Pacific Ocean plates beneath the western margin of the North American plate. In such fossil subduction complexes, it is generally difficult to reconstruct details of the accretion of continent-derived sediments and to evaluate the...
In Nusa Tenggara Barat (NTB), Indonesia, shrimp is one of the most produced seafood. It contributes to 8.74% of total Indonesian shrimp production value. In order to improve aquaculture practices including shrimp farms, Ministry of Marine and Fisheries Affair of Republic of Indonesia recently issued General Guideline for “Minapolitan” (fisheries...
Concurrent satellite-measured chlorophyll (CHL), sea surface temperature (SST), sea level anomaly (SLA) and model-derived wind vectors from the 13+ year SeaWiFS period September 1997 – December 2010 quantify time and space patterns of phytoplankton variability and its links to physical forcing in the Pacific Ocean. The CHL fields are a...
Most data are associated with a place, and many are also associated with a moment in time, a time interval, or another linked temporal component. Spatiotemporal data (i.e., data with elements of both space and time) can be used to assess movement or change over time in a particular location,...
Understanding sandbar dynamics and variability is integral to developing a predictive
capacity for nearshore flows, sediment transport, morphological change, and
ultimately for determining coastline exposure to damaging storm waves. Along the
high-energy U.S. Pacific Northwest (PNW) coast, sandbars typically dominate the
bathymetry of the active zone. Here we report on...
The Glass Buttes volcanic complex is a cluster of bimodal (basalt-rhyolite), Miocene to Pleistocene age lava flows and domes located in Oregon's High Lava Plains province, a broad region of Cenozoic bimodal volcanism in south-central Oregon. The High Lava Plains is deformed by northwest-striking faults of the Brothers Fault Zone,...
Oxidized hydrous intermediate composition magmas are responsible for porphyry copper (Cu ±Mo ±Au) deposits and epithermal Au ore deposits formed globally in the shallow crust (Sillitoe, 2010; Seedorff et al., 2005). Recently, zircon geochemistry has been used to characterize both productive and barren intrusions associated with porphyry Cu-Au ore deposits....
The nearshore waters off the Oregon coast (< 73 meters) are a region of high productivity and economic value, with a variety of habitats that include rock outcrops. Temperate reef habitats are important to many commercially important fishes inhabiting the Pacific coast, including canary rockfish (Sebastes pinniger) and yelloweye rockfish...
All major web mapping services use the web Mercator projection. This is a poor choice for maps of the entire globe or areas of the size of continents or larger countries because the Mercator projection shows medium and higher latitudes with extreme areal distortion and provides an erroneous impression of...
A wide variety of different rock types were dredged from the Tonga fore arc and trench between 8000 and 3000 m water depths by the 1996 Boomerang voyage. ⁴⁰Ar-³⁹Ar whole rock and U-Pb zircon dating suggest that these fore arc rocks were erupted episodically from the Cretaceous to the Pliocene...
Seamounts are a ubiquitous feature of the seafloor but relatively little is known about their internal structure. A seamount preserved in the Franciscan mélange of California suggests a sequence of formation common to all seamounts. Field mapping, geophysical measurements, and geochemical analyses are combined to interpret three stages of seamount...
We have applied a normalized difference algorithm to 8 day composite chlorophyll-a (CHL) and fluorescence line height (FLH) imagery obtained from the Moderate Resolution Imaging Spectroradiometer aboard the Aqua spacecraft in order to detect and monitor phytoplankton blooms in the Oregon coastal region. The resulting bloom products, termed CHL[subscript rel]...
In an attempt to understand the phase equilibria and petrogenesis of MORB anorthitic plagioclase, Cr-spinel commonly hosted within anorthitic plagioclase has been investigated petrographically and compositionally. Based on spinel-anorthite relationships from three samples of plagioclase ultra-phyric basalt (PUB; Southeast Indian Ridge, Axial Seamount and West Valley Segment, Juan de Fuca...
This paper details a method to compute absolute water velocity profiles from glider-based acoustic Doppler current profiler (ADCP) measurements based on the "shear method" developed for lowered ADCPs. The instrument is a 614-kHz Teledyne RDI ADCP integrated into the body of a Teledyne Webb Research Slocum Glider. Shear is calculated...
Climate Change in the Northwest: Implications for Our Landscapes, Waters, and Communities is a report aimed at assessing the state of knowledge about key climate impacts and consequences to various sectors and communities in the Northwest United States. This report draws on two recent state climate assessments in Washington in...
During rapid variations of the atmospheric mixing ratio of a trace gas, diffusive transport in the porous firn layer atop ice sheets and glaciers alters the isotopic composition of that gas relative to the overlying atmosphere. Records of past atmospheric trace gas isotopic composition from ice cores and firn need...
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Coastal Education and Research Foundation (CERF) and can be found at: https://doi.org/10.2112/SI65-235.1
Spatial coherence between predators and prey has rarely been observed in pelagic marine ecosystems. We used measures of the environment, prey abundance, prey quality, and prey distribution to explain the observed distributions of three co-occurring predator species breeding on islands in the southeastern Bering Sea: black-legged kittiwakes (Rissa tridactyla), thick-billed...
Large ignimbrite flare-ups provide records of profound crustal modification during batholith formation at depth. The locations of source calderas and volumes and ages of the eruptions must be determined to develop models for the tectonomagmatic processes that occur during these events. Although high-precision isotopic ages of the ignimbrites are critical,...
We investigated the export of particulate organic matter (POM) to the ocean by two contrasting small, mountainous rivers, the Umpqua and Eel Rivers, by collecting suspended sediment samples over a range of discharges and analyzing them for a variety of constituents, including organic carbon, nitrogen, biomarkers with distinct biochemical sources,...
Rain falling at or near low tide is capable of eroding and transporting cohesive sediment from intertidal areas. Given that metals adsorb strongly to silt- and clay-sized particles, it is conceivable that low-tide rainfall may also liberate previously-deposited metals from storage in intertidal sediment. To investigate the potential for rainfall...
Polar ecosystems are sensitive to climate forcing, and we often lack baselines to evaluate changes. Here we report a nearly 50-year study in which a sudden shift in the population dynamics of an ecologically important, structure-forming hexactinellid sponge, Anoxycalyx joubini was observed. This is the largest Antarctic sponge, with individuals...
Ice cores are considered the gold standard for recording past climate and biogeochemical changes. However, gas records derived from ice core analysis have until now been largely limited to centennial and longer timescales because sufficient temporal resolution and analytical precision have been lacking, except during rare times when atmospheric concentrations...
Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This thesis contains two manuscripts that respectively investigate the (1) initiation processes of debris flows in these glaciated catchments, and (2) debris...
Marine microorganisms play a significant role in the cycling of nutrients in the open ocean through production, consumption, and degradation of organic matter (OM). Carbon (C), nitrogen (N), and phosphorus (P) are essential ingredients in every known recipe for life. However, the cycling of each of these elements proceeds at...
Disease, overharvesting, and pollution have impaired the role of bivalves on coastal ecosystems, some to the point of functional extinction. An underappreciated function of many bivalves in these systems is shell formation. The ecological significance of bivalve shell has been recognized; geochemical effects are now more clearly being understood. A...
A new method is introduced for incorporating bathymetric uncertainty into predictions of nearshore and river flows (i.e., unstratified flows primarily forced by pressure and radiation stress gradients). The method involves the use of the ensemble Kalman filter (EnKF) as a parameter estimation scheme, where the parameter to be estimated is...
The 2008-2009 eruption of Chaitén Volcano (Chile) involved a variety of volcanic and associated hydrologic processes that damaged nearby forests. These processes included coarse (gravel) and fine (silt to sand) tephra fall, a laterally directed blast, fluvial deposition of remobilized tephra, a variety of low-temperature mass-movement processes, and a pyroclastic...
Concentrations of domoic acid (DA) above the regulatory limit in Washington coast razor clams are usually higher on northern beaches from summer to fall. Recent field studies have confirmed that the primary source of toxic Pseudo-nitzschia (PN) cells in those seasons is a semi-retentive topographically trapped seasonal eddy located offshore...
The western United States is experiencing significant changes in wildfire and snow regimes as a result of warming temperatures. An amplification of wildfire activity and reduction in snow water equivalent, snow covered area, and earlier spring snowmelt are documented trends that are projected to continue into the future. With an...