Heavy metal pollution from a smelter in Trail, British Columbia may be a source of anthropogenic Pb contamination in northeastern Washington lakes. This smelter, located near the Canadian border, has been operating since 1895. It dumps slag – waste created during smelting – into the Columbia River, and emits metals into the atmosphere. We analyzed sediment samples from lakes in northeastern Washington to determine the source of anthropogenic Pb. Determining whether smelter Pb travels via airways and contaminates the environment is a critical health issue. We measured Pb isotope ratios of lake sediments on a multiple-collector inductively coupled plasma mass spectrometer, following acid dissolution of the samples and separation of the Pb. Lead isotope ratios provide a tool to trace anthropogenic Pb. Pb206, Pb207, and Pb208 are daughter products of U238, U235, and Th232, respectively. Pb204 is not produced by radioactive decay. Each parent isotope has a different half-life, so different geological sources have different relative amounts of each Pb isotope. This gives every Pb source its own Pb isotope fingerprint. No natural processes alter the fingerprint of a Pb source after industrial processing. Therefore, we can test for smelter emissions in lake sediments. Lake sediments contain natural and anthropogenic Pb. In Pb207/204 vs. Pb206/204 space, Pb from slag samples has relatively low values, with Pb206/204 ratios from 16.7-17.4. Natural Cascade Pb has much higher isotopic ratios with Pb206/204 ratios of 18.5-19.0. Lake sediment Pb covers most of this range, with Pb206/204 ratios from 17.02-18.32. All analyzed samples contain significant anthropogenic Pb. Lakes closer to the smelter generally show higher contributions of anthropogenic Pb concentrations. Additionally, the gradation in anthropogenic Pb contamination forms a pattern expected from prevailing winds transporting smelter emissions. The Pb isotope data provide strong evidence for airborne Pb contamination of some Washington lakes from the Trail, British Columbia smelter.

In seeking to put future climate change in context, researchers have used past glacier fluctuations as a proxy for temperature. While an undeniable correlation exists between a warming climate and shrinking glaciers over long time-scales, it has also been shown that the interannual climate variability that occurs in a constant climate can drive large-scale glacier fluctuations. In other words, there is a classic statistical problem of identifying a signal-to-noise ratio. This study seeks to establish how large a change in glacier length needs to be in order to be considered statistically significant. Physically, this study asks how far a glacier must recede, and how quickly, before one can say with confidence that a trend exists. Two glacier models, one linear and one dynamic, based on the geometry and weather patterns of Mt. Baker glaciers in Washington State, USA, are randomly forced in a constant climate and the resulting time series are used for statistical analysis. The statistical significance of a trend depends in large part on constraining the effective degrees of freedom contained in a glacier record. A glacier is a large block of ice and thus has more inertial resistance to change than the weather that forces it. Glacial flow is therefore an integration of multiple years of previous climate forcings. This memory of previous years means the change in glacier length one year does not represent independent information about the current climate; a glacier can lengthen even if the temperature warms for a period. We present several methods for correcting for this effect, and evaluate the power of two standard trend tests for detecting whether a given glacier trend should be attributed to climate change.

The warmest climatic event of the last 34 million years occurred during the middle Miocene, culminating in the Middle Miocene Climatic Optimum, (MMCO; 17-15 Ma) which was a period of substantial warming. The climate change likely affected plant community composition as grasses spread across North America, but because plant macrofossils from the MMCO in North America are rare, the response of vegetation to this warm interval is poorly understood. We combine analysis of plant silica (phytolith) assemblages and study of stable carbon isotopes from the same paleosols to document vegetation changes during the MMCO in southwestern Montana. Phytolith assemblage analysis provides information about vegetation structure, as well as the composition of grass communities, whereas isotopic data allows determination of the proportion C3 and C4 plants. The site near Drummond, Montana, has previously produced Barstovian-aged mammals and is productive for phytoliths. Our results show that grass silica short cells, diagnostic of grasses, in particular C3 pooid grasses, dominate assemblages (up to 75%). The remainder of the assemblages is made up of phytoliths typical of forest indicators, including palms, woody and herbaceous dicotyledons, and conifers. This suggests a fairly open habitat, with grass communities dominated by C3 grasses. Preliminary stable carbon isotope data are consistent with the phytolith results, indicating dominantly C3 plants (90% or above) in the samples. Lateral and vertical sampling from the site shows very little variation in phytolith composition, indicating low spatial and temporal variability.

Foraminifera are a diverse and extensive group of marine shelled protists that are found all over the world, including Puget Sound. Because foraminifera are relatively abundant, short-lived and susceptible to environmental change, they have the potential to be inexpensive and effective environmental monitoring tools for local estuaries. Since Puget Sound exploits its water ways for industrial profit, foraminifera could prove to be useful tools for environmental monitoring. Thus it is surprising that, to date, no one has ever catalogued and observed foraminifera in the Sound to search for any changes in structure, abundance or diversity that could indicate a change in the environment. In fact Puget Sound is the only industrialized waterway that has not done this. The purpose of this project is to assemble an atlas of the foraminifera found in Puget Sound, from Bellingham Bay to south Sound. This atlas contains photographs, and in-depth descriptions of each foraminifera species. A catalogue such as this is a useful tool because it helps to better understand the foraminifera of Puget Sound and furthers the understanding of the organisms and their ecosystem.  This atlas can also be used as a quick and easy reference to compare any changes discovered among foraminifera and their communities. Ultimately, the complete atlas will be submitted to Paleontologica Electronica for publication.

The goal of this study was to obtain an age of the marine Quillayute Formation by correlating fossils from other similar rocks in Washington and Oregon. The Quillayute Formation, located along the outer coast of the Olympic Peninsula, Washington, consists of fossiliferous marine sandstones and siltstones, and its age has been controversial. Obtaining the correct date will allow for further understanding of the geologic history of the Olympic Peninsula, especially the rates of tectonic uplift and determining the climate at time of deposition. The Quillayute Formation has 37 identified species of fossil gastropods and bivalves. These fauna have been compared with those of the geographically and temporally closest units, the Quinault Formation (Washington) and the Empire Formations (Oregon). The Quinault Formation is Early Pliocene in age (3.6-5.3 million years), based on benthic foraminiferal biostratigraphy. The age of Empire Formation is Late Miocene (5.3-11 million years), determined by magnetostratigraphy and diatom biostratigraphy. To obtain the age of the Quillayute rocks, a comparison of age ranges of each of the correlative species was made. Results of this identified 15 species from the Quillayute Formation that also occur in the Empire Formation, and are apparently restricted to the Miocene. Six species are in common with the fauna of the Quinault Formations and those are still-living taxa.

Current research in Himalayan geodynamics focuses on the complex relationship between surface erosion and active rock uplift. This study focuses on the Eastern Himalayas, where the Yarlung-Tsangpo River abruptly turns southward, incising over a 2 km deep gorge through the easternmost Himalayan mountains to join the Brahmaputra River in Assam. Because geologists have primarily concentrated on just the surface geology, they have struggled to explain this massive gorge despite over a decade of research. Our research takes a new approach to this aging problem by examining the sedimentary record immediately downstream of this gorge. In fact, sedimentary rocks of the eastern Siwalik foothills preserve the full record of Himalayan uplift as well as the evolution of the river systems draining the Tibetan Plateau. Here we focus our research, interpreting the sedimentary record through both detrital zircon U-Pb dating, which is a radiometric dating technique, and modal analysis, which is an evaluation of the minerals present within the samples from these Siwalik units. Past research results suggested a stable sedimentary provenance sourcing from both Himalayan and Tibetan source rocks, but new higher resolution modal analysis will add valuable insight into the competitive influences of progressive roofing of the high Himalayas and sediment recycling in the Himalayan foreland. Furthermore, this research provides valuable new data for a region of the Himalayas where there is currently a deficiency of information from the sedimentary record. This information is necessary for a full comparison of landscape evolution westward across the great Himalayan arc, and also shows a regional relationship between climate and tectonics.

The purpose of this study is to investigate the effects of different pollutant sources in Sinclair and Dyes Inlets, both located in Puget Sound, Washington. Puget Sound is a fjord-like waterway extending from Olympia, Washington to the Canadian border. Sinclair Inlet and Dyes Inlet are connected by the Port Washington Waterway near Bremerton in Kitsap County, Washington. Bremerton is the home of Puget Sound Naval Shipyard. This naval base is a Superfund site that discharged large amounts of industrial pollution into Sinclair Inlet. In comparison, agricultural and residential pollution are deposited in Dyes Inlet from streams surrounding the perimeter of the inlet. This study aimed to analyze foraminiferal assemblages to determine if environmental changes through pollution and other factors have affected the health of the Bremerton area marine ecosystems. Foraminifera are shelled single-celled marine microorganisms that react to environmental stresses, thus they act as good indicators of environmental change. Foraminifera were collected from a total of 21 samples provided by the Washington State Department of Ecology from 1998-2009. Thirteen of these samples were taken from Dyes Inlet and 8 were taken from Sinclair Inlet. This study focused on examining the density and diversity of foraminifera from 1998-2009. Our results show that Dyes Inlet contains a low diversity of foraminifera with 7 different species found. However, 2 samples did not contain any foraminifera and several samples from more recent years only contained one species. In Sinclair Inlet, 15 species were identified in total, but diversity was nearly cut in half over the time period studied. The dominant species in both inlets was Elphidium hannai. By comparing foraminiferal assemblages from our locations with samples from less anthropogenically impacted locations in the Puget Sound, we can begin to analyze the potential effects of different types of pollution on the health of Puget Sound.

The Moon does not have a dipolar magnetic field, like that of the Earth. Instead, the Lunar surface has areas of magnetized crust called magnetic anomalies. Many of these magnetic anomalies are coincident with features called lunar swirls - regions with high-albedo or high-reflectance material. As many of these lunar swirls often appear in the same location as areas of relatively intense magnetic fields, one of the leading hypotheses explaining the formation of the lunar swirls is that the surface is shielded from the surface darkening solar wind by the magnetic anomalies. We seek to further understand the connection between the visual high albedo and the magnetic anomalies by creating three-dimensional models of the magnetic fields and particle deflection around well-known lunar swirls. We do this through the use of a three-dimensional particle tracking program. The particle tracking program simulates solar wind interacting with the magnetic field and determines the final location of the solar wind particles on the surface of the Moon. This work focuses on the results for simulations of the Mare Ingenii swirl region. Preliminary results show that the particles are in fact deflected, and as expected the smaller electrons are more highly deflected. Better understanding of the origin of the Lunar swirls not only allows us to gain insight into the process of space weathering and magnetic shielding but can also offer clues for methods to mitigate the harmful effects of solar wind and particle radiation during human space travel and at lunar or Martian human colonies.

The purpose of this study was to do a temporal investigation of the benthic forminifera in northern Puget Sound, specifically Semiahmoo Bay north of Bellingham Bay, to correlate any fluctuations in species diversity or abundance with environmental parameters. Semiahmoo Bay is influenced by an influx of both sediment and water from the Fraser River as well as mixing with ocean waters that travel in through the Strait of Juan de Fuca. The area is of interest because it is less impacted by anthropogenic activity than the rest of the Puget Sound and this allows for comparisons with other areas that are more heavily industrialized. Foraminifera are single celled, marine protists with specific habitat requirements. The sensitivity of these animals to their ecosystem allows us to use them for environmental monitoring. This study examines the foraminiferal genera and species present in sediments from this region spanning twelve years; from 2001 to 2012. The samples used were collected by the Washington Department of Ecology annually in April. Results of this investigation show an average of 15 species of foraminifera were present each year with three species dominating the samples. These species are Bucella frigida, Elphidium frigidum and Elphidium hannai, which are present in every sample. There are 10 to 12 other species that occur in small numbers present in most samples. One species, Cassidulina limbata, which is intolerant to pollution, indicates that this water is clean. There are only a few agglutinated species found in Semiahmoo Bay which is in contrast to the high abundance found in Bellingham Bay. This is significant because the dominant agglutinated species in Bellingham Bay are known to be opportunistic colonizers of polluted waterways. Thus, the foraminiferal assemblage in Semiahmoo Bay corroborates the hypothesis that the area is not subject to the degree of environmental stress as other embayments of Puget Sound.

After the Great Japan Earthquake in 2011, people’s interest in earthquake risks and hazards in the Pacific Northwest (PNW) has increased due to the tectonic similarity between the PNW and Japan. However, a recent study focused on the perception of hazards and risk amongst University of Washington (UW) students indicated deficiencies in knowledge, perception of risk, and preparedness. In contrast, the overall degree of earthquake readiness in Japan is higher than in the PNW due to a strong culture of safety, accurate knowledge, and a high level of risk perception. The higher level of earthquake readiness in Japan indicates effective communication between the scientific community and general public. The objective of this research is to assess the success of earthquake-education programs in Japan, identify missing elements in the PNW’s education programs, and investigate the preferred communication method of people in the PNW. My work compares the earthquake-education programs, resources, style of communication, and cultural differences between Japan and the PNW. My comparisons suggest a combination of school, self, family, and community educations appears to enhance and increase Japanese individuals’ awareness and preparedness. For example, Japanese schools employ standardized guidelines from the Board of Education to maintain highly consistent education programs. Additionally, the active involvement of family and community in Japanese earthquake hazard education motivate individuals to take necessary actions for mitigation activities. In contrast, earthquake-education programs in the PNW are infrequent and lack a standardized source from the government and scientific authority and the education efforts are infrequent. These results indicate the need for more effective earthquake-education and preparedness in the PNW. Future work will be specifically looking into the preferred communication methods between the scientific community and UW students.

Orbital spectroscopy provides evidence for the presence of liquid water throughout the history of Mars through analysis of the surface composition. In order to determine surface mineralogy, we use remotely sensed visible/near-infrared spectroscopic data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board the Mars Reconnaissance Orbiter. We identify minerals by their unique absorptions at specific wavelengths through the examination of CRISM surface reflectance data across 438 wavelengths from 1.0 to 3.9 microns. Spectral datasets like CRISM contain large volumes of data and each spectrum usually covers an area that contains several unique compositions, or spectral endmembers. Factor analysis uses a set of mixed spectra to derive a set of orthogonal eigenvectors and associated eigenvalues. Although physically meaningless, the eigenvectors and eigenvalues can then be used to estimate the number of components present in a mixed system. Target transformation is used to reconstruct endmember spectra using a linear combination of the set of eigenvectors, even if those pure endmembers do not exist in the original data. In practice, the target transformation test is simply a least squares fit of the significant eigenvectors to laboratory spectra. If a laboratory spectrum can be closely matched, then it is a possible endmember present in the system. This methodology can also be used to remove noise and significantly improve the quality of CRISM data. We tested our methodology using CRISM data containing evidence for the presence of carbonates. Target transformation clearly confirmed the presence of Mg-rich carbonates and phyllosilicates in Nili Fossae, a series of extensional faults. We are automating this technique and applying this methodology to test for a variety of minerals across the entire planet. Ultimately, by applying our data analysis technique to the global CRISM dataset, we will have a more detailed understanding of surface composition and aqueous processes on Mars.

The late Oligocene (~23-28 million years ago) Blakeley Formation of Puget Sound has received multiple interpretations over the past century, ranging from a coastal embayment to a submarine fan. The formation is exposed along an uplifted terrace just south of the Seattle fault zone, in a discontinuous east-west band across Puget Sound. At Alki Point, the formation appears as an asymmetrical northeast plunging anticline and is characterized by fossiliferous siliciclastic siltstone and mudstone, typically in units several meters thick. These fine-grained units are interbedded with limestone in the lower part of our measured section and with sandstone in the upper part. Deposits of reworked volcanic ash and pumice are scattered throughout the section as well. The overall lithology and paleontology of the section suggests that the Blakeley Formation at Alki Point was deposited in a continental shelf environment. Sandstone beds in the upper section are broadly consistent with distal storm deposits, indicating a relatively shallow depth (< 100m). Finer sediment size and the absence of storm deposits in the lower section suggests deposition in somewhat deeper waters, perhaps in a middle to outer shelf environment. Some siltstone beds contain fossil bivalve shells, calcareous concretions, and infilled burrows, which are characteristic of cold methane seep ecosystems. The presence of reworked tephra, possible volcanic flood deposits, plant debris, and the general immaturity of sediment at Alki Point indicate that sediment was probably supplied by a river draining an active, ancestral Cascade volcano. Based upon the abundance of volcanic material in the sediments, it is also likely that the volcano was nearer the open coast than current Cascade volcanoes are. A possible modern analog for the Blakeley Formation of Alki Point might be the eastern Japan-island arc, where rivers deposit sediments from nearby volcanoes onto the continental shelf.

Pyroclastic density currents (PDCs) are ground-hugging currents of hot gas and particles that travel at velocities up to 300 m/s. Because of the inherent danger of observing PDCs in real time, we rely on the deposits for insight into the dynamics of these dangerous currents. Our research uses the well-exposed PDC deposits from the May 18, 1980 eruption of Mt St Helens (WA) to explore how PDCs are influenced by surface roughness. The PDCs produced during the eruption flowed through areas of low and high surface roughness. We mapped and sampled deposits from a single PDC proximal, medial, and distal distances from the source, focusing on changes with distance from source and a comparison between deposits in areas of low and high surface roughness. In general the PDC deposits display poor-sorting and are massive in nature, suggesting deposition from a concentrated current with rapid sedimentation. Grain size and componentry data of deposits downstream from preexisting debris avalanche hummock, which provided high surface roughness, contain a threefold-increase in hummock components relative to PDC deposits in areas of low surface roughness. This suggests that high surface roughness promotes the erosive capacity of PDCs. The main driving force for PDCs is their great density relative to the air, thus increasing the density at the base of the current through substrate erosion could potentially increase the run-out distance, thereby increasing the destructive radius. The results from this research substantiate previous research that erosion by PDCs is a common occurrence, but also demonstrate that surface roughness is a primary contributor to the potential for erosion. Future work should explore the consequences of erosion on downstream dynamics. This will impact the ability of hazard mapping models to more accurately determine areas that are at risk for PDC interaction in the vicinity of volcanoes throughout the world.

The infamous May 18, 1980 eruption of Mount Saint Helens, Washington (USA) produced several episodes of pyroclastic density currents (PDCs) including the initial lateral blast, which traveled nearly 30 km, and later PDCs in the afternoon, which filled in the area up to 8 km north of the volcano. The afternoon PDCs differed from the lateral blast in that they had a higher particle concentration and filled in the topography up to 30 m. While the concentrated portions of the afternoon PDCs followed deep topographic drainages down the volcano, the dilute overriding cloud partially decoupled to develop fully dilute, turbulent PDCs on the flanks. This research focuses on the dilute PDCs, which deposited thin, cross-stratified, and stratified pyroclastic deposits known as proximal bedded deposits. In order to understand the influence of topography on the formation of these dilute currents and the influence of slope on the currents’ transport and depositional mechanisms, we collected samples from recently exposed deposits, analyzed them via grain size measurements, and combined them with data from an unpublished thesis written in 1988 by David Beeson (University of Texas at Arlington). This allows us to assess modes of origin and transport of dilute PDCs. Results show that bedform amplitude and wavelength increase with increasing slope, as does the occurrence of regressive dunes. The relationship between bedform morphology and flow velocity is an important finding since the controls on bedform wavelength and amplitude remains poorly constrained. This finding is further supported by the occurrence of chute and pool features on steeper slopes relative to progressive dunes on shallower slopes. The collected data will be used to validate numerical models that map and quantify the hazards of PDCs, improving both our understanding of PDC dynamics and the hazards associated with them.

The mountain pine beetle (MPB) infestation in British Columbia (BC) forests ranks among the largest scale ecological disturbances recorded to date and thus presents a unique testbed for understanding forest dynamics and associated climatic feedbacks. Previous work has shown that BC MPB infestation affects the local surface energy balance, decreasing evapotranspiration and increasing surface temperature. Based on this study and related physics, we hypothesized that there may be greater cloud cover over affected areas of BC post-disturbance relative to pre-disturbance. To explore this hypothesis, we used forest inventory data together with data from the Geostationary Operational Environmental Satellite (GOES) imager to quantify the impact of the devastation on summertime cloud development. Using published calibrations, we transformed raw counts at visible and infrared wavelengths to reflectance and temperature, respectively. We then made cloud maps by applying threshold criteria to the derived reflectance and temperature. Visual inspection of the cloud maps compared to the forest mortality map suggests no obvious difference between the pre- and post-disturbance cloud scenes. Ongoing work is attempting to verify and quantify this qualitative result. Because cloud development processes can have an important influence on the local climate, our research will show whether climatic effects of this ecological disturbance could raise additional concerns about the MPB issue in BC.

During the last glaciation (18,000–13,000 years ago) a lobe of the Cordilleran Ice Sheet advanced into the Puget Lowland, scouring and sculpting the previous landscape into the present-day topography. Prior to the Puget Lobe’s advance, Cascadian alpine glacial systems had reached their maximum extent and were depositing large volumes of sediment into the Puget Lowland basin. While the extensive glacio-fluvial deposits that are preserved in the Puget Lowland indicate a thick sequence of sediment had filled the basin prior to the Puget Lobe’s advance, there has been no previous research on the source (or provenance) of these sediments. Much of this outwash sediment is currently attributed to the Puget Lobe, although a significant volume was likely deposited by Cascadian glacier sources prior to the Puget Lobe’s advance. I have collected samples from glacio-fluvial sediment and Puget Lobe till at bluff exposures on Whidbey Island, as well as alluvium from present-day Cascadian river drainages (a proxy for paleo-Cascadian glacio-fluvial outwash) that can be used to obtain a modal analysis of the basin fill. I analyze these samples using a microprobe to evaluate the proportional occurrence of source-indicative minerals in order to determine the provenance of Puget Lowland sediments. My expected results are for minerals present in the Cascadian drainage sediments, e.g., garnets, to occur in larger proportions than in the Puget Lobe sediments due to source-bedrock composition. For example, the result of high garnet (or other indicator mineral) content in Lowland sediments would indicate that the sediment was deposited by Cascadian glacio-fluvial source rather than by the Puget Lobe, redefining which depositional units are attributed to each source. Knowing the relative volumes of sediment deposited by these two sources will allow me to calculate alpine versus continental glacier sedimentations rates in the region during the last glacial maximum.

Pulsed plasma thrusters are a modular electric propulsion technology with extensive flight heritage. Flight-ready PPTs are tailored to a specific mission based on the power and mass budget of a mission. The lower bound for both parameters is far less than competing electric propulsion (EP) technologies, such as Arcjets and Hall Thrusters, which makes them desirable as spacecraft size decreases. The variable components of PPTs are typically electrode geometry, capacitor size, spark plug geometry, and fuel feeding system, but rarely if ever does a space mission select an unusual fuel. Teflon is used almost exclusively, and PPT fuel research is effectively stagnant. This investigation has concluded that alternative fuels are indeed significant. The sulfur PPT (SPPT) is inspired by natural sulfur plasmas in the Jovian magnetosphere. Thrust stand tests over the course of six months have demonstrated clearly that the specific thrust (thrust per unit power) is three times higher than in a corresponding test using a Teflon PPT of the same electrode geometry. Both pure sulfur and a sulfur-epoxy binder have been considered, and show the same specific thrust within error of the experiment. Pure sulfur will outgas in space, and may not be suitable for long missions, but the sulfur-epoxy fuel could potentially solve this problem. Additionally, an insulated semi-conductive bismuth sulfide compound shows similar thrust characteristics to the Teflon fuel, albeit at a lower exhaust velocity. This investigation is ongoing, with a parallel application project performing the SPPT experiment on a high-altitude balloon airship. This mission will demonstrate systems control, test the SPPT in a non-laboratory environment, build flight heritage, and represent and important advancement in PPT applications.

The distribution of temperature and precipitation on our planet (i.e. our climate), affects plant growth, animal habitats, and the livability of Earth's varied regions. In order to predict future climate we need to know about our past climate. This is important to better understand how temperature and weather conditions change when the radiative forcing (e.g. CO2 greenhouse effect) on our atmosphere increases. The best way to predict these changes is researching past radiative forcing increases and how these events impacted Earth’s climate. Some details of our past climate are discovered by analyzing polar ice and the gas bubbles trapped within. Firn is fallen snow that compacts and eventually turns into glacial ice. During this process gas can move relatively freely throughout the firn. When the firn densifies enough to block the air passageways, young gases are trapped in significantly older ice. This work is building a web-based community firn densification model that allows the user to accurately determine the difference between the age of a gas sample and the age of the ice surrounding it. Our transient model determines this delta age more accurately than current steady-state models by accounting for changing conditions as the firn turns into ice, instead of assuming conditions remain static throughout the firn evolution. This model is open-source, and written using the Python programming language, along with the NumPy library, allowing the model to be free and usable by anyone. Because the model is modular, users can easily change it to fit specific conditions or to incorporate different physical processes. Our goal is to provide a model that is simple to use, freely available, and helpful for developing a more accurate understanding of our past climate.

The unique geography and ice dynamics of the West Antarctic Ice Sheet (WAIS) are believed to make it susceptible to instability and rapid collapse. Predictions of WAIS stability in a warming world rely heavily on ice sheet model simulations; one drawback is that ground truth for these models comes from the last ice age, when the climate was colder. Geologic evidence of ice sheet behavior during warm interglacial periods is currently hidden beneath the Antarctic and Greenland ice sheets. We expect WAIS to have been thinner and less extensive under warmer conditions, and we ultimately plan to determine its past extent with cosmic ray exposure dating of subglacial bedrock. As a prelude to subglacial sampling, during January-February 2013 we collected samples from elevation transects of exposed granitic bedrock at three WAIS nunatak sites: the Pirrit Hills, Nash Hills, and Whitmore Mountains. We also conducted radar reconnaissance surveys to evaluate potential sites for future subglacial rock sampling, which will extend the transects beneath the ice sheet. We have separated out the quartz and potassium feldspar content of our samples for measurement of cosmogenic beryllium-10/aluminum-26, and chlorine-36 respectively. We are using the results of these analyses to determine the history of exposure and ice cover in the past 1-2 million years at each sampled elevation. Based on field observations, we expect our samples to show evidence of prolonged exposure, suggesting that presently subglacial surfaces were also exposed in the past. Ultimately our work will determine whether rock surfaces beneath the WAIS have ever been exposed to cosmic rays, providing clear evidence for or against a thinner ice sheet in the past. Such data will be useful in tuning ice sheet model conditions and establishing WAIS vulnerability to collapse, which is crucial to forecasting future sea level change.

Over the past few decades various electrical propulsion systems have been developed to facilitate space exploration. Plasma propulsion is a form of electrical propulsion of particular interest, in that it is especially efficient for the purposes of long-duration interplanetary space travel. Specifically, the high power helicon (HPH) thruster is a plasma propulsion system that utilizes a helicon antenna to ionize a neutral gas and create high energy plasma. This project has focused on the production of a B-dot probe to measure magnetic field perturbations in the plume of the HPH double-gun configuration. The configuration will have two HPH thrusters mounted next to each other and fired simultaneously. It is known by Faraday’s law of induction that time-varying magnetic flux through a closed circuit induces an electromotive force in the circuit. At the end of the B-dot probe are three coils of wire, whose circular loops are arranged into a sphere. Using the B-dot probe, the time derivative of the magnetic field component normal to each loop can be found, for each of the three vector components. The time derivative of the magnetic field can then be integrated over time to find the changes in the magnetic field. These changes in the magnetic field will be compared to those that result when only a single HPH thruster is fired. It is expected that the double-gun configuration will produce stronger magnetic field perturbations downstream than will a single HPH thruster. Measuring changes in the magnetic field with the use of a B-dot probe will provide a better understanding of the performance of the double-gun configuration and how it can be improved.

On Mars, the properties of CO₂ radiation frost formed in a CO₂ atmosphere are basically unknown, but are important to understanding the polar caps, atmosphere, and climate of Mars. The broad-band solar albedo and infrared emissivity of Martian seasonal frost deposits dominate the annual polar heat balance, which controls a significant amount of seasonal variation in atmospheric mass as well as the potential for atmospheric collapse at the extremes of Mars epochal obliquity variations. Our goal is to perform realistic laboratory simulations of the thermal and radiative environment on the surface of Mars and produce the first-ever samples of carbon dioxide frost formed the same way it does on Mars, by radiative cooling in a nearly-pure CO₂ atmosphere. To create and analyze simulated Mars CO₂ frost, we have been constructing a Radiation Frost Chamber (RFC). The outer shell of the chamber has already been constructed so my specific role in the research and development process is to help acquire, design, build, and test components to be used for measurements and experiments in the RFC; specifically, a fiberscope, a calibration cup, quartz beads, and other Martian soil analog materials. The fiberscope will be used to view and record the physical morphology and texture of the CO₂ frost. Also, its output light will help measure the broadband and spectral albedo of the frost. The quartz beads are being used for testing a theoretical model for thermal conductivity of planetary soils and the calibration cup is going to be used for testing techniques to measure ice content of soil. The base will contain the Mars analog soil at about 600 Pa of pressure of CO₂ in order to simulate the Martian environment. Once the RFC has been built it is our goal to finally simulate the Martian environment in a lab setting accurately.

UVC is ultraviolet light in the wavelengths 280 – 100nm. UVC’s germicidal ability has been employed to prevent forward contamination, or the contamination of a pure planetary body with terrestrial organisms. Scientists have used UVC to sterilize equipment on land and water, but the effective dose of UV needed to prevent contamination when probing a pure ice environment is still unknown. In order to safely explore pure icy environments, data of bacterial response to UVC in ice are needed. To create these data, we first irradiated Escherichia coli in water as there is a known decimation curve for this experiment, which serves to standardize our irradiation set up and techniques. After matching the decimation curve of Escherichia coli of previous UV sterilization experiments, we will then proceed to irradiate bacteria in ice. In addition to irradiating commonly tested bacteria such as Escherichia coli and Bacillus subtilus, we will also irradiate samples of glacial isolates that would be more likely contaminants in an icy environment. Each sample of bacteria will be assessed before and after radiation using the Most Probable Number technique, or MPN. The MPN method uses serial dilutions of a sample bacterial culture until no colony forming bacteria are present to determine the concentration of bacteria present in the original sample. From our irradiations, we will create curves of UV dose versus survival of bacteria that will allow future equipment used in the exploration of pure icy environments to employ the correct dosage of UVC light to minimize forward contamination.

During the last ice age the Missoula Floods – huge cataclysmic floods caused by failure of the glacier dam that impounded Lake Missoula, a massive ephemeral meltwater lake – spilled across eastern Washington in periods of a few days. Repeated floods transformed the Eastern Washington landscape, eroding coulees and re-working the resulting sediment into extensive sand, gravel, and boulder deposits. Although widely studied, debate persists over the number and timing of the floods. Flooding is known to have spanned a period of several thousand years; this is constrained by several areas of research including radiocarbon dates, dated volcanic ashes, and examination of the interbedding of Missoula Flood deposits with those of the 18,000 yr BP Bonneville Flood on the Snake River. To further constrain the chronology of flooding, we plan to measure the cosmic ray produced isotope Beryllium-10 in granitic quartz from boulder deposits near Ephrata, and at Priest Rapids on the Columbia River. Concentrations of Be-10, accumulated since the boulders were deposited, will allow us to determine their exposure ages. So far, we have collected several samples from the Ephrata boulder fan and from the Priest Rapids deposit. We have sampled high-standing, water-polished boulders to avoid the effects of past sediment cover and post-depositional erosion, both of which can lead to erroneous age estimates. We have crushed the samples and separated quartz in preparation for Be-10 analysis. After further purification, the quartz will be dissolved for extraction and isotopic analysis of Beryllium. We expect results of this work to better constrain the relative timing of the deposits at Ephrata and Priest Rapids, and the age of the floods that produced them, the last to pass through the Grand Coulee and Sentinel Gap, respectively.  

Our 800,000-year climate record is dependent primarily on data obtained from ice cores. Analyzing and dating the ice, gas, and sediment in these cores allows us to construct a remarkably accurate historical record of Earth's climate and atmosphere. However, the dating and chronology of the ice record is not as exact as we would like it to be, especially deeper in the ice. Our ability to date ice cores with accuracy depends on our understanding the evolution of glacial firn, fallen snow that gradually compacts into ice. Researchers have developed many different models of firn evolution. The aim of this project is to run these models against each other under the same boundary conditions, so that we may compare their responses and determine the strengths of each model. Participants have submitted their model output and our results have been returned to them. A second inter-comparison will be organized to address issues brought up by our initial results. These comparisons will improve future efforts in firn-modeling, ultimately leading to a better understanding of our climate record.