The McMurdo Dry Valleys in Antarctica is a cold desert with a frigid, hyperarid environment. Physical models predict that the sediments should have a net loss of water vapor, but in reality ice-cemented ground is pervasive within decimeters of the surface. Scarce, episodic snowfall is mostly lost to rapid sublimation; however, some water vapor may diffuse into the subsurface and possibly stabilize or form ground ice. This study investigates ice within a 30-m permafrost core that was collected from Beacon Valley in 2008 using a dry coring technique. The entire core is ice rich, ranging from 20-80% water content by weight and is largely composed of weathered sand with some fractured cobbles. The high ice content suggests that the ground surface inflated as the ice formed. Processes leading to the excess accumulation of ice are investigated using δ18O and δD. Potential sources of the ice include surface percolation, water vapor diffusion, and accumulation of snow into thermal contraction cracks. Subsamples of the ice-cemented core were cut from its interior, thawed, and the water was collected using a double-bottom centrifuge tube. Isotope analysis was also performed on water samples from hoarfrost collected from the abandoned core holes, snow, and glacier ice in Beacon Valley. The core’s isotope depth profiles will provide information on the origin of the ice and processes that modify it. This site serves as an analog for Mars, where excess ground ice has been confirmed at the Phoenix landing site, and will provide insight on ice accumulation there.

In the late 1920s, geologist J Harlen Bretz proposed that a catastrophic flood - larger than any in human history - had carved the Channeled Scablands of Eastern Washington State. Established geologists rejected this theory as impossible and repeatedly attempted to discredit and deny his work. Undeterred, Bretz continued to research the Channeled Scablands and ultimately wrote 15 comprehensive academic papers on the subject. His megaflood theory did not see wide acceptance until the 1960s. Modern writings about J Harlen Bretz all tell the same story; he was a rebel protagonist with an outrageous theory who was vehemently opposed by his fellow geologists until vindication finally arrived after 40 years. But where did this story come from? Bretz's history has been recorded through academic papers, biographies, newspaper articles, and popular sources online. I use the language of these varied sources to explain how the perception of J Harlen Bretz changed from heretic to hero over the course of 40 years. The evolution of Bretz's legacy highlights that the process of science is not always as rational, dispassionate, and removed from human emotion as we would prefer to believe. It is a case study for the role of human nature in scientific pursuit.

Non-traditional isotopes have become increasingly important as tracers for geological and environmental processes on earth. Recently, renewed attention has been direct towards potassium (K) isotopes given the abundance of K in the earth and the potential for significant mass-dependent fractionation between ⁴¹K and ³⁹K. There is little existing research on K isotopes primarily due to analytical difficulties, however recent technological developments have made precise analysis possible. Seawater has the potential to be an excellent geostandard for K isotope geochemistry because of predicted ⁴¹K/³⁹K homogeneity through the water column, and its wide accessibility around the globe. A total of forty-seven, 30 mL samples were collected in July 2015 aboard the R/V Thomas G. Thompson on the VISIONS 2015 Expedition to Axial Seamount on the Juan de Fuca Ridge. Samples were collected from CTD (Conductivity Temperature Depth) casts as well as niskin bottles operated by the Remotely Operated Platform for Ocean Science (ROPOS). Seawater profile samples were taken at several locations from 7 m down to 2890 m. Evaluating the K isotopic composition at each depth and geographic location will determine if the K isotope composition of seawater is homogeneous and therefore if seawater may be useful as a future geostandard. If K behaves similarly to other non-traditional isotope systems, ³⁹K will preferentially be released into the hydrosphere during weathering, leaving the residual rock enriched in ⁴¹K. This behavior will be useful in constraining the process of granite weathering, and its effect on the K budget in the hydrosphere. In chemical oceanography, there is thought to be a missing sink for K, and it is theorized that clay formation, crustal fractures, or both may remove K from seawater. Determining the feasibility of seawater as a geostandard for K isotopes will further facilitate new research in these and other geochemical topics.

Electric propulsion is an area of increasing research as it offers increased efficiency and versatility in operation. Electric propulsion systems ionize solid propellant and accelerate plasma out the back of spacecraft at high velocities using electric and magnetic fields to create thrust. Pulsed plasma thrusters (PPT) are an example of how electric propulsion offers a lightweight and cost-effective source of in-space propulsion for small spacecraft with space and power limitations. Traditional solid propellants like Teflon provide adequate fuel for PPTs but are limited by space and weight thresholds for small spacecraft. The Advanced Propulsion Lab (APL) at the University of Washington is interested in exploring the use of dust as a fuel source in PPTs. Dust would prolong the life and therefore research capabilities of such spacecraft due to its universal availability. In addition to using planetary/asteroid dust, we are interested in de-orbiting and using particle-sized pieces of retired space debris as a source for fuel. We hypothesize favorable thrust values for small spacecraft can be obtained by igniting dust in a PPT. The dust thruster is mounted inside a small vacuum and operates by using high frequency vibrations to agitate micrometer-sized particles into a plume of very fine dust that is sparked via firing a PPT. We are experimenting with Martian regolith simulant (a synthetic manufactured Mars dust), lunar regolith simulant (synthetic lunar dust), and aluminum powder, but the dust thruster can utilize virtually any dust sample. This experiment will serve as a proof of concept that dust particles can be used as a main fuel source for PPTs. The dust thruster is a sustainable system that will allow for longer missions and thus increase research capabilities, while proposing a sustainable solution to space debris traffic.

The CubeSat form-factor is an increasingly popular design of small satellites utilized by a range of research orginizations. Consisting of stacks of 10x10x10cm cubes, CubeSats offer a compact and inexpensive means to place equipment and instrumentation into low-earth orbit, but suffer from limited or non-existent maneuvering capabilities. Currently available propulsion options for CubeSats may offer limited abilities to modify the shape of an orbit near to Earth, but suffer constraints on propellant efficiency, thrust duration, and thrust force. A new design of compact pulsed plasma thruster from the University of Washington for use on small satellites offers improved abilities to maneuver in not just low-Earth orbit but also in lunar insertion, lunar orbit, Earth escape trajectory, and a variety of trajectories reaching beyond. The orbital mechanics team has been responsible for studying the motion of PPT powered satellites in space and for the plotting of trajectories to potential mission targets. As the PPT has significantly different levels of thrust and efficiency from conventional liquid-fueled rockets, unique solutions to conventional problems must be found.

Studies suggest that Europa contains elements required to support life beneath its icy crust, but further data collection is required for verification. One of the largest issues in performing such a research expedition is the demanding cost of soft-landing an instrument on its surface to retrieve the data. To address this issue, research is currently being conducted for a new method involving a two-stage penetrator probe which would allow the hard-landing of the probe into the moon’s surface. The initial stage penetrator would weaken the ice and create a debris plume which would allow the second stage probe to decelerate and enter the surface intact. To optimize the system and further study its potential, the impact is being simulated in the ANSYS finite element analysis software. In working parallel with experimental data obtained from impact testing, the geometry and parameters within ANSYS were modeled to create a FEA explicit dynamics simulation of the impact. The analysis models the ice as concrete due to material properties of ice being difficult to obtain, and local mesh refinement methods were utilized to improve computational time. The focus of the simulation is to determine the optimal model in which the first stage penetrator has significant impact in the acceleration profile of the second stage probe. The impact pattern, the amount of material carved out, and the acceleration profile of the probe will be analyzed to relate the efficiency of various penetrator geometries at various speeds. Impacts involving the two stage system with various penetrator geometries show significant reductions in the acceleration profile of the probe. Future research will rely on refining the simulation parameters to derive a more accurate model of the impact.

Fed by a large upwelling of hot viscous rock originating deep in the Earth’s mantle, the Yellowstone hotspot has been carving its history into North America for over 50 million years. As the North American tectonic plate moves westward over the mantle plume, magma erupts through the crust creating a chain of large volcanic centers stretching from west to east, ending at the supervolcano under Yellowstone National Park. Despite its large size, tracing the history of the Yellowstone mantle plume is a difficult task. Geologic processes, including subsequent eruption of the subduction-related Cascade volcanoes, have altered the crust since its passage over the Yellowstone hotspot. In Washington and Oregon, young basalts (<5 million years old) erupted with unusual compositions similar to mantle-plume-related basalt such as found in Hawaii. However, these mantle-plume-like basalts erupted when the Yellowstone plume was far to the east, no longer located under Washington State. Our project uses isotope and trace element analyses to determine the origins of these unusual basalts in Oregon and Washington. We test the hypothesis that remnants of the Yellowstone plume continue to influence local volcanism. Rare-earth element abundances are typical of mantle-plume (e.g., Hawaiian) basalts. Our samples show high concentrations of the elements niobium and tantalum, indicating an origin outside of normal subduction processes. Most diagnostically, ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁸Pb /²⁰⁴Pb, and ²⁰⁷Pb /²⁰⁴Pb isotopic ratios of our samples are similar to the Columbia River and Steens basalts in Eastern Washington and Oregon, two volcanic provinces formed by the Yellowstone Hotspot 16 million years ago. The results of our Pb and trace element analyses suggest the presence of a mantle plume component in recent volcanism west of the Cascadia volcanic arc. We hypothesize that this component reflects the melting of material incorporated from the Yellowstone plume head.

As a response to the NASA Cubesat initiative, the UW ESS department started the effort to design and build a 3U Cubesat by the students from various technical backgrounds. 3U Cubesat is made of 3 units vertically stacked onto each other with each unit at 10x10x11.35cm. This team is assembled within the UW Cubesat project to work on the structure system of the Cubesat and is responsible for solving problems in structure system. Recent progress regarding the CAD modeling of the body, designing and manufacturing of the hinges, deployers, solar panel mounting and ideas about fixed solar array and launcher possibilities are discussed. Various models have been proposed and tested and the overall capability of the hinges is improved to better suit the mission. For getting the maximum exposure of sunlight and keeping the whole system optimal, different solar panel solutions were assessed. Deployer design to release the Cubesat from the launching system and to release the solar panels from the Cubesat body was studied. Before machining the deployer and hinge system at its actual size, multiple tests have been done on the enlarged 3D-printed versions of the deployer and hinge system to make sure the design works properly. Among our team members, the tasks to design and implement each section are collaborative and everybody made sizable contributions to the progress. The current results produced include a design of the full body CAD model for the 3U Cubesat and its major components, a preliminary design of the deployer and hinge system undergoing its initial testing stage, a decision to use existing design of PPOD launcher and a design of the location and dimensions of the solar panels. Multiple models and their respective numerical estimations have been used in multiple presentations and will be presented at the day of the Symposium.

Europa is one of Jupiter’s moons which is covered in ice. Further research on Europa is needed to determine if the moon can sustain life. One of the barriers that has affected our understanding of the moon is the large velocity requirements to land on Europa, which make a soft landing on the surface too costly. To overcome this problem, research has being performed on penetrator technology that can withstand a hypervelocity impact. The initial system involves the study of the performance of a two-stage penetrator. The first stage would break the ice, making way for the second stage. The second stage of the penetrator would encounter weaker ice and therefore have a higher probability of surviving the impact. The electronics would be located in the second stage. Projectiles have been tested on impact qualities and post-impact properties. Further experimentation has been performed with various designs and materials that have varying densities. Density is expected to play an important role in the depth of penetration and the resulting deceleration forces on the system. Penetrators made of Lexan have been used along with wood as impact material. Seven inches of penetration has been achieved when fired at speeds close to 1 km/s. Smaller scale testing, at lower speeds, has been performed on larger Lexan projectiles fired into ice resulted in approximately 1.5 in. of penetration. Projectiles made of aluminum have been tested and fired into a bucket of ice. The ice was kept at -20° C, which is still significantly warmer that the surface conditions of the moon. Once the penetrators are optimized for these temperature conditions, additional testing would involve liquid nitrogen to cool the ice to colder temperatures. The penetrator system could lead to the discovery of new life, future missions to Europa and possible habitation or resource extraction.

Our planetary next-door neighbor, Mars, is a top candidate for near-future human settlement. Resources such as water ice are known to exist inside Mars’ porous regolith, and the ability to find and utilize resources is an important step toward putting astronauts on Mars’ surface. Our project investigates the influence of ice on the thermal properties of planetary regolith. Models predict that a .01% increase in regolith ice increases thermal conductivity by a factor of 5. Because the stability of water ice has a strong dependency on its thermal environment on a planet with little atmosphere such as Mars, an understanding of how thermal properties of regolith are influenced by ice will provide great insight into where ice exists. However, this relationship is not yet well-supported with empirical evidence, so we are designing and testing an apparatus to measure thermal conductivity of regolith with varied amounts of ice content. The apparatus uses a thermoelectric cooler to cool the sample to -10° Celsius and create sinusoidal temperature waves that propagate through the sample. Temperature sensors at specific heights measure the wave properties to determine thermal conductivity. Currently we can take temperature and weight measurements from the apparatus, and our next steps are to control humidity in the experiment with nitrogen gas, and calibrate a fiber-optic spectroscopic measurement technique to determine regolith ice content to higher precision than allowed by weight measurements. Understanding how ice content affects regolith thermal conductivity will help us further understand the conditions under which regolith ice is stable, and allow us to predict the location of ice on a planet by analyzing thermal inertia data from remote-sensing satellites. This method of locating ice and similar resources will prove valuable in planning crewed missions and determining ideal locations for human colonization on Mars and elsewhere in the solar system.

This research is being conducted in order to discover more about surface and subsurface ice on other planets—specifically Mars. Liquid water is considered one of the primary requirements of life, and we now know that Mars has a vast quantity of water, but nearly all of it in the form of ice in its large polar caps and shallow buried ground ice present at all latitudes above ~50 degrees. There is much geologic evidence that liquid water has flowed on Mars’ surface in the past, and possibly even the present day, but the properties and processes that control the stability and behavior of water on Mars are poorly known. Knowledge of the properties of ground ice would aid in understanding the polar ice caps, atmosphere, and climate of Mars; this is necessary in order to assess when and where life could have existed on the red planet. Our goal is to study this ice by building a vacuum chamber that will contain icy regolith, creating a temperature gradient in it, and taking in situ measurements of the results. These measurements will be conducted through fiber optics as well as by removing the samples and taking them to a cold room for analysis. Hopefully, these measurements will allow us to understand both the subsurface ice and the planet Mars itself.

This study investigates the effects of anthropogenic pollution and mitigation efforts in Elliot Bay, Puget Sound, by analyzing the relationships between pollutants and benthic foraminiferal assemblages from 1998, 2007 and 2013. Foraminifera are single-celled microorganisms, which are typically encased within secreted shells (tests) comprised of either calcium carbonate (calcareous) or cemented sediment grains (agglutinated). Foraminifera are commonly found in marine environments and are a valuable tool for monitoring environmental conditions of the past and present. Elliot Bay has an extensive history of pollution, beginning with the European settlers establishing lumber mills in the 1850’s, and continues to have many industrial and recreational sources of pollution today. For this study, a total of 45 samples collected by the Washington State Department of Ecology in 1998, 2007 and 2013 were analyzed to identify any changes or trends in foraminiferal assemblages. From these samples, 21 species were recovered and identified, most of which are stress-tolerant species found in estuaries around the world. Some species are more tolerant of pollution and stress, and so have been more informative of the environmental conditions in Elliott Bay. For example, the agglutinate species Eggerella advena, found abundantly in some 2013 samples, is an opportunistic colonizer of industrial and sewage outfalls. In addition, the calcareous species Buliminella elegantissima and Cribroelphidium excavatum, also widely present in the bay, are tolerant of low oxygen environments. Correlations of species density and diversity with heavy metals such as copper, zinc, lead, arsenic, cadmium, and mercury result in a better understanding of the impacts of pollution and mitigation in Elliott Bay.

Much of the topography of Eastern Washington was shaped by the recession of the Cordilleran Ice Sheet and by periodic flooding from Glacial Lake Missoula towards the end of the last ice age. The age of flooding is approximately known from Carbon-14 dates, but because the floods distributed granite boulders across much of Eastern Washington we can improve the chronology using exposure dating with cosmic-ray-produced nuclides. In this method, the build-up of Aluminum-26 and Beryllium-10, two isotopes produced in quartz by cosmic rays, indicates the length of time these boulders have been exposed. By applying this technique to selected deposits we can shed light on the age of the last floods, sources of floodwater, and how the extent of the Cordilleran Ice Sheet controlled the floodwater paths. Initial data show that the last floods through Grand Coulee occurred approximately 15,500 years ago, but younger floods passed down the Columbia Gorge until approximately 14,100 years ago. This final flood may represent breaching of the glacier-ice dam across the Columbia River, or a glacial outburst flood from a more distant source. We can distinguish these possibilities by dating glacial deposits on the Waterville Plateau and in the Okanogan Valley. One exposure age on a glacial erratic from north of the Columbia River near Brewster gives an age similar to the final flood, possibly suggesting that the flood resulted from breakup of the Columbia River ice dam. Chemical analysis and accelerator mass spectroscopy of additional samples will give us a more accurate picture of the chronology of the last of this catastrophic flooding.

For this investigation, I developed a repeatable Geographic Information System (GIS) model using Esri's ArcMap software to test if and under what circumstances rivers preferentially erode along surface fault traces. The motivation for this study stemmed from the fact that geoscientists have long assumed that strain along faults weakens rock and leads to focused erosion. Such positive feedbacks between faulting and surface processes have yet to be investigated at the scale of major fault systems. River networks in New Zealand, an active obliquely convergent tectonic setting with hundreds of surface breaking faults, are examined. The goal is to identify river reaches that travel parallel and along the faults - a first step in estimating whether and under what circumstances preferential erosion exists. Two digital datasets were used: active fault data from GNS Science (New Zealand's geological survey) and river data from LINZ Data Service (New Zealand's national land mapping agency), both freely available. The GIS model uses the Model Builder feature in ArcMap to assign each fault a layer. The model then selects faults of a particular length and adds a buffer. The size of the buffer selects the rivers to be studied. The rivers selected are noted as either bisecting or traveling parallel to the fault. Rivers within the buffer and traveling parallel to fault strike are selected and can then be further analyzed to calculate metrics such as the percentage of the fault with river running along it, lengths of river segments that flow along faults, and other variables such as fault type, slip rate, and fault strike. This GIS model is meant to be transportable to other large fault systems such as the San Andreas Fault zone in California, with the ultimate goal of extracting tectonic information directly from earth's surface.

A method will be presented for dating the last time sub-glacial mountains in West Antarctica were fully exposed by measuring the cosmic-ray-produced isotope ⁴¹Ca. The use of ⁴¹Ca will add a new cosmogenic isotope to the existing toolbox to improve surficial dating. The advantage of ⁴¹Ca over other isotopes is its short half-life (99,000 years), which reduces the complication of prior exposure in natural samples. To accomplish this, calcium will be extracted from Antarctic bedrock samples, converted to oxalate, and then further treated by column ion exchange to produce pure calcium, free of problematic potassium contamination. The biggest challenge will be to produce calcium hydride for measurement by accelerator mass spectrometry (AMS) to determine the ⁴¹Ca/⁴⁰Ca ratio. Current AMS capabilities allow ratio measurements in the 10-10 or 10-11 range. Measurements of the hydride should allow us to extend this down to the 10-14 level necessary for geological applications. Successful measurements in this range will open up applications such as tests for whether sub-glacial bedrock in West Antarctica was exposed to cosmic rays during the last warm interglacial climate period, approximately 120,000 years ago. Perfecting this method and making it available to others in the field can open a door into the past to determine if current global warming trends are leading us down a path similar to the last deglaciation, which raised global sea level by several meters. Though we are working on a geological and glaciological issue, the ultimate product of this research touches areas of meteorology, biology, and sociology as the Earth adjusts to increases in global temperature.

Sediment cores were recovered from Limnaea Sø and Braya Sø, closed-basin lakes in Southwestern Greenland, to reconstruct temperatures during the Holocene epoch (past ~10,000 years). The closed-basin topography makes the lakes ideal for studying changes in evaporation and precipitation, and variations in past lake conditions are recorded by authigenic carbonates in the lake sediments. The sediment cores were analyzed by x-ray, magnetic susceptibility, and bulk density to allow stratigraphic correlation between cores and to determine changes in sedimentation rate and lithology. After sectioning, a series of samples taken 20 cm apart were sent for radiocarbon dating, which placed the samples between present day and 9.5 ka (Calendar age). Due to the deposition rate (~0.1 mm/yr), these sediments were sectioned at 0.5 to 1 cm intervals to achieve ~100 year resolution. A series of samples were analyzed for total organic carbon, which provided insight into the history of vegetative changes surrounding the lakes. Samples were then prepared for δ13C and δ18O isotopic analysis on the Kiel Carbonate system/isotope ratio mass spectrometer. The δ13C and δ18O data show periods of isotopic changes, indicating either a strong change in the hydrologic regime or changes in surface air temperatures. We are analyzing these abrupt periods using novel clumped-isotope paleothermometry to determine whether the isotopic variations are a response to lake temperature variations as previous alkenone analyses indicate, or shifts in precipitation/evaporation patterns. While work from ice cores show relatively stable temperatures during the Holocene epoch, recent lake sediment records have suggested that temperatures may have been more variable than thought. If our results show no significant temperature variations, it will confirm previous interpretations based on δ18O that large shifts in the hydrologic cycle occurred. The clumped isotope paleothermometry technique will be the first of its kind applied to Greenland lake sediments to produce a temperature reconstruction.

Our research project was to design, construct, and launch a high powered rocket with the intention of pushing its velocity significantly past the speed of sound while simultaneously collecting data from which to interpret the max achieved acceleration, velocity, and altitude. The rocket's body has a three inch inner diameter made to fit the 3-inch motor casing without any extra room. This minimum diameter design reduced its weight so that less force was required to achieve higher acceleration, and it provided a smaller cross sectional area than a traditional rocket, thereby reducing the amount of drag force impeding its acceleration. Atypical of most high powered rocket designs, our rocket features a metal tipped nose cone to provide resistance to the heat caused by friction when breaking the sound barrier. At the speeds achieved, unmodified rocket fins will vibrate at extreme rates due to turbulent flow. In order to combat this destructive effect the fins were reinforced with carbon fiber to significantly stiffen them and reduce any resonant effects during flight. The payload consists of a StratoLogger SL100 Altimeter to keep track of the maximum altitude and velocities of our flights as well triggering two separate parachute deployments, achieving a safe landing while also minimizing drift time due to winds at altitude. It is our hope that our research rocket will push the boundaries of velocity and altitude achieved by a junior college rocket team as well as provide insight into ways to optimize our rocket designs to maximize future results.

This research details the design, construction, modeling, launch and post-flight analysis of a high-powered rocket through the Earth and Space Sciences’ Rockets and Instrumentation course at the University of Washington. The primary goal was to build and test a multistage cluster rocket, scheduled to launch March 2016 in Black Rock, NV. To exploit the exponentially decreasing drag at high altitudes the rocket was initially designed as a two-stage, with eight external motors and two internal motors providing 43 kN-s of total thrust with a max velocity of 750 m/s. Risk assessment shows three-stage ignition as a safer option, providing a ground launch of 10 kN-s of thrust. Once the main engine burns for 2 seconds, the external cluster motors will ignite, providing 19 kN-s of impulse before separating from the main stage at around 20,000 feet. The sustainer motor then ignites at a final impulse of 14 kN-s and will reach an apogee of approximately 47,000 feet. The recovery package was designed with two separate systems of dual deployment for drogue and main parachutes, as well as a GPS and an altimeter, using two different flight computers, one in each stage. Previously untested commercial telemetry instrumentation was chosen and simulated with electromagnetic software before launching. If the rocket performs as designed, it will be the highest rocket built and flown by a University of Washington student group.

Repeating earthquakes are a common feature of the seismicity of active volcanoes, defined as any number of earthquakes that share the same source and are detected based on the similarity of their waveforms. Often, the waveforms of these repeating earthquakes change subtly with time, indicative of changes in the volcanic system. We use the technique of coda-wave interferometry to determine if the source or medium (e.g., seismic velocity) is changing with time. It has been shown that seismic velocity changed significantly immediately prior to the 2004 eruption of Mount St. Helens, and that these changes correlated with changes in the amount of seismicity. We take a similar approach using a catalog of repeating earthquake swarms during the eruption of Redoubt Volcano in 2009, to determine if there is a similar correlation between velocity changes and seismicity changes prior to a different eruption. Initial results indicate that the velocity dropped prior to at least two explosions, coincident with an increase in seismicity. We attribute the change in velocity to an increase of pressure in the system, which props open cracks, causes local inflation, and reduces seismic velocity. Furthermore, the increased pressure would also drive an increase in seismicity. These techniques may prove useful as part of a monitoring system, providing we can demonstrate the phenomenon is unique to eruptions and ubiquitous among them.

The Redbluff landslide, situated at Washington-Oregon state border, is part of the larger Bonneville landslide complex. In 1450 A.D., the Bonneville landslide dammed the Columbia River, but the river eventually breached it. In the present day, only one part of the landslide complex, namely the Redbluff landslide, is still slowly creeping into the Columbia River. It also poses a risk of damaging nearby public infrastructure. Interferometric synthetic aperture radar (InSAR) is a remote sensing technique used to measure millimeter-scale surface deformation. These satellite data are complemented by Light Detection Ranging (LiDAR), which is used to produce high-resolution topography images. Using these observations, I seek to understand how the movement of the Redbluff landslide relates to the surrounding geology and morphology. The downslope landslide movement is computed by back-projecting the line-of-sight InSAR observations onto a downslope vector, as done by previous InSAR glacier studies. ArcGIS software will be used to produce a higher-resolution model of the landslide movement. Furthermore, surface roughness will be computed as a geomorphic proxy of active movement on the slope. I expect that the InSAR surface displacement will show active movement in the regions with highest surface roughness. The InSAR and LiDAR data sets are highly complementary data sets and both help to better characterize landslide hazards along the Columbia River.

Climate change has raised concern on the possibility of West Antarctic Ice Sheet collapsing in the future, in which the ice sheet thins substantially, resulting in a sea level rise. In assessing the possibility of future collapse, scientists are researching whether the West Antarctic Ice Sheet had collapsed during a warmer period in the past. Delta O-18 records from an ice core originating from Siple Dome, West Antarctica indicates that the deeper section of the Siple Dome ice sheet had originated from a much higher elevation area. This indication suggests that ice that was deposited in the high-elevation central West Antarctic could have flowed horizontally through a melting ice sheet to settle at the base of Siple Dome today. Here we modeled an age-depth relationship for an ice column at Siple Dome to test if it is possible to have a melting scenario here during the last interglacial period (about 110 000 years ago) based on this 1-D model. We traced the flow trajectory of the ice particles in the column back to the surface where it was first deposited as falling snow. We used a Dansgaard-Johnsen model with time-varying accumulation rate and ice sheet thickness, and included a melting variable for the interglacial scenario. Constraints on past thickness and accumulation rate and comparison of model result to available ice-core data allow us to determine whether this model may or may not describe the ice flow trajectories that make up the column of ice at Siple Dome today. If the result matches the ice core data, this implies that the model may be valid, and that some part of West Antarctica might have collapsed during that interglacial period.

Phytoliths are microscopic silica bodies that are produced in the tissues of many vascular plants. Over the course of their lifetimes, certain plant cells become filled or encrusted with silica that the plants have absorbed from soil. Grasses produce a diverse range of phytolith shapes that distinguish them from phytoliths produced by other plants. We hypothesized that it would be possible to distinguish certain grass clades by the unique phytolith shapes they produce and the relative abundances of these shapes. We sampled a range of grass species across the grass-family phylogeny, including from grasses that diverged early on in the evolution of this clade. We isolated phytoliths from dried grass material and created permanent slides that were examined using a light microscope. For each grass species, we counted and categorized all phytolith shapes observed and calculated the relative abundance of each shape. These counts allowed us to identify grass clades based on the relative abundances of phytolith shapes they produced. Our results are a reference collection of phytoliths found in modern grasses that can be used as a key for identifying grasses in the fossil record. When applied to deep-time vegetation studies, this information can help identify grasses from ancient ecosystems. Because the spatial distribution of grass species vary depending on environmental factors such as temperature and humidity, our work can also help provide past climatic and environmental information. Studying grasses is important because they are an important part of Earth’s ecosystems and are a major food crop for humans.

Clusters of rocket motors are classically arranged cylindrically for the purpose of maximizing the effective aerodynamics of the overall cross-sectional design. Alternatively, our team’s rocket booster engine configuration was arranged in a unique square formation around the main engine for the first stage of our launch. This not only simplified construction and reduced the need for extra material to support the engines, but also lent itself to increased stability by making use of the corners of the square as part of the fin design. This first stage consisted of nine identical motors ignited simultaneously. Once the second stage ignited, this nine-engine cluster detached from the rocket and propulsion continued via a single motor. Speeds reached approximately 550 m/s, which is to say approximately Mach 1.6. The mainframe was constructed of carbon fiber with Kevlar reinforcement to prevent the fins from self-destructing upon breaking the sound barrier and/or ground impact. Our payload consisted of electronics for measuring and transmitting acceleration, speed, and altitude, along with a GPS unit for tracking purposes. The rocket's objective was to reach 60K feet, the maximum altitude allowed by FAA regulations, with a supersonic square cluster design modeled after SpaceX’s Falcon9. The research conducted was to study the takeoff, flight stability, and landing of our rocket’s more efficient square orientation in comparison to a typical cylinder design.