Tag: Earth Science

Welcome to the Jam: Effects of Climate on Mid-winter River Ice Breakup

Presenter(s): Annalee Nock − English

Faculty Mentor(s): Dave Sutherland

Poster 174

Research Area: Earth Science

Dynamic breakup of river ice cover and subsequent ice jamming, or damming, can cause flooding with socio-economic and ecological impacts. Breakup processes are sensitive to weather conditions, so changing climatic patterns engender concern over their potential impacts. Understanding how to predict ice jamming events could both mitigate destruction and offer insight toward climate’s effect on river ice. Usually, breakup and flooding happen in the spring, but occasionally perturbations in winter temperatures invoke mid-winter ‘thaws’. These are influenced by rainfall, augmented river flow, and ice decay. By synthesizing hydroclimatic studies on mid-winter breakup and ice jams, my research shows these mid-winter events have repercussions on ensuing spring breakup. This demonstrates the magnitude of even slight warming on river ice. With more high-resolution data and quantifying research, cryologists can look at mid-winter breakup as both a predictor for spring events and an easily-perceptible representation of climate change.

The Cascades and Snow Drought: What it Means for the PNW

Presenter(s): Lauren Jin − Pre-Journalism

Faculty Mentor(s): Dave Sutherland

Poster 162

Research Area: Earth Science

For much of the Western United States, mountain snowpack is one of the main sources of water. This is especially true for the Pacific Northwest states, Oregon and Washington, because while rainfall provides sufficient water during the wet months, residents rely on water stored in the snowpack during the summer. This snowpack has been declining: snow water equivalent (SWE) records show this and there have been many studies on the extent and causes of this loss. While it is understood that the snowpack in the Cascades is declining, it is less understood how this loss relates to drought, and specifically snow drought. Snow drought is the combination of general drought and reduced snowpack, but only a few drought metrics account for the water stored in snow. This project will attempt to better quantify snowpack drought in terms of snowpack loss and examine the variables behind it. In this study we will use SNOTEL records from the NRCS and previous research relevant to the project. Snow drought is major concern for water resource managers and must be better understood in order to prepare for it in the future.

The Effect of Climate Change on Coastal versus Inland Snow: The Expected, the Counter- Intuitive and their Connection

Presenter(s): Adriann Bechtle − Architecture

Faculty Mentor(s): Dave Sutherland

Poster 140

Research Area: Earth Science

Although the impact climate change has on the cryosphere as a whole is generally understood, the way it plays out in different regions varies and may sometimes seem counter-intuitive. The west coast and midwestern United States are two regions that exemplify the dichotomy between familiar and surprising effects of climate change because their weather is affected by different things and their cryospheres take on nuanced forms. On the west coast the snow is largely limited to high altitudes and it accumulates there to create glaciers. In the midwest, on the other hand, the vast majority of snow
is annual and is highly dependent upon weather patterns. The observable trends in both regions is a decline in snowpack, whether that is annual or accumulative snowpack. Both trends appear to be a direct products of global warming. What differentiates these regions is the change in precipitation and the ways these changes affect the environment and human populations. The west coast is largely suffering from a decline in precipitation and is losing snowpack as a result. This creates a drought because the snowpack is a significant water source. Meanwhile the midwest is actually having an increase in severe winter precipitation, this has its own catastrophic consequences. The question is how these phenomena are connected and if they share an underlying cause. By comparing and contrasting trends in winter precipitation and snowpack from both regions we can see what aspects of climate change are universal versus regional and potentially answer our question.

Decompression Experiments of the Mono Craters Eruptions of 1340 C.E.

Presenter(s): Eamonn Needham − Earth Sciences

Faculty Mentor(s): Jim Watkins, Thomas Giachetti

Poster 4

Research Area: Earth Sciences (Geology)

Funding: UROP mini grant

The Mono Craters, California eruptions of 1340 C.E. were a series of eruptions that produced relatively texturally homogeneous deposits, with the exception of the first bed. The initial eruptive deposits differ from later deposits in
the relative abundance of obsidian pyroclasts (quenched magma), volatiles (H2O and CO2), and microlites (minerals <100μm). These textural differences between Bed 1 and the other beds remain unexplained, but may be due to changes in decompression rates. To test the decompression rate hypothesis, a sample of synthetic Mono obsidian was run in a cold seal pressure vessel at eruptive conditions. The sample was kept at 850°C and 60 MPa for 2.5 days, and then was decompressed isothermally at a rate of 0.001 MPa/s until it reached 5 MPa. Following rapid quench, bubble number density and microlite number density were determined from scanning electron microscope images. In the future, more of these experiments will be run at different decompression rates, to see which decompression rate best match the textures of the Bed 1 samples. The calculated decompression rate will be compared to decompression rates of later deposits which were calculated in other studies using volatile concentrations. If Bed 1 has a different decompression rate than the later beds, this could explain the textural differences, and can be used to look at how the eruption initiated and progressed. This research could have implications for the ongoing debate of eruptive style transitions from explosive to effusive, which in turn will inform hazard mitigation for volcanoes exhibiting this behavior.

Identifying Fossils: Horses of Kyrgyzstan in the Miocene

Presenter(s): Dylan Carlini − Geology

Faculty Mentor(s): Samantha Hopkins, Win Mclaughlin

Oral Session 4O

Research Area: Earth and Biological Science

In paleontology, correct identification of fossils is of paramount importance to the scientific process. In locations with sparse fossil records and little preexisting literature, such as Kyrgyzstan, fossil identification can be particularly difficult. For this study, I identified two previously unidentified specimens from the University of Oregon Kyrgyz fossil collection as a mandible and a cheek tooth from the genus Hipparion, a member of family Equidae. Following a review of relevant paleontological literature, I used digital calipers to gather precise measurements of the specimens and conducted a careful analysis of tooth cusp morphology in order to make the determination. While the two specimens cannot be definitively attributed to the same individual, I determined that both came from adult individuals of the genus Hipparion. Using tooth morphology from the mandible, I also estimated the age of the individual at the time of death. These identifications add to our knowledge of the biodiversity of Miocene central Asia. Additionally, this study serves to demonstrate the process of fossil identification.

Fossils of Oregon: Mammalian Body Mass Communities in the Miocene

Presenter(s): Dylan Carlini − Geology

Faculty Mentor(s): Samantha Hopkins, Dana Reuter

Poster 9

Research Area: Earth and Biological science

Funding: Presidential Undergraduate Research Scholarship
UROP Mini-Grant

The size of an organism relates to a host of other characteristics about a species such as diet, metabolism, and trophic level. Changes in body mass through deep time are often the result of changing environments and climates. Previous research has examined how the patterns of mammalian body size at a community scale are shaped by the environments the organisms inhabit. However, the fossil record of Eastern Oregon has never been investigated through that lens. The extensive fossil record and well-studied long-term environmental shifts in Eastern Oregon make it an ideal location to study the effects of environmental changes on mammalian body masses. This study intends to classify and quantify the effects of the spread of grasslands on body size structure of mammals in the Miocene. I estimated body mass for Miocene mammals using measurements from fossil teeth as a proxy. These estimates derive from measurements taken with digital calipers and from the computer program Image J. I then organized the body masses into size categories and compared the changes in size structures as Oregon developed from a closed woodland in the middle Miocene to a more open, grassland environment in the late Miocene. If a pattern is discovered, it could help inform biologists and ecologists which varieties of mammal are at the greatest risk of climate-change related extinction in the near future.

Lobodon carcinophaga: Evolutionary constraints on the spatial variability of crabeater seal postcanine teeth for successful filter-feeding foraging strategies

Presenter(s): Megan Pollak—Earth Sciences—Paleontology

Faculty Mentor(s): Kellum Tate-Jones

Session 6: The Earth, Sky & Everything In Between

Pinnipeds, the group that includes true seals, eared seals, and walruses, generally display highly variable tooth spacing . Previous studies have credited this variability to the typical pinniped feeding mechanism, a combination of suction feeding and pierce feeding known as the “grab-and-gulp” method, which does not require precise dental occlusion . However, the crabeater seal (i .e ., Lobodon carcinophaga) is unique among pinnipeds as a filter-feeder . The distinct sieve-like postcanine tooth processes such as high-cuspation and intricate trellis-like morphology allow the crabeater seal to effectively strain small krill from the water . I hypothesize that individuals in this group with unevenly spaced teeth are unlikely to survive ecological pressures and are thus removed from the population by natural selection, leading to lesser variation in crabeater seal tooth spacing than in grab-and-gulp feeders . I test this hypothesis by assessing whether the distinctive feeding method of the crabeater seal constrains tooth spacing by comparing the variability in tooth gaps of crabeater seals to that of bearded seals (i .e ., Erignathus barbatus) . I measured the tooth gaps between the postcanine teeth of 21 specimens of L . carcinophaga and 11 specimens of E . barbatus . I then performed an F test of equal variance on these two datasets . I found that crabeater seal tooth gaps are significantly less variable in spacing than those of bearded seals . This result supports my hypothesis that natural selective processes have generated evolutionary constraints for lower variability in tooth spacing in the filter- feeder, L . carcinophaga, than in grab-and-gulp feeders such as E . barbatus .

The Evolution of Camelids in the Pacific Northwest in Response to the Grassland Expansion

Presenter(s): Eleanor Froehlich—Earth Sciences

Faculty Mentor(s): Samantha Hopkins, Dana Reuter

Session 6: The Earth, Sky & Everything In Between

Camelids, the artiodactyl group including camels, llamas, and alpacas, evolved in North America during the Eocene . The first camelids were smaller than a goat; however, some extinct genera were giraffe sized . Most studies of North American camelids focus on fossils found in the Great Plains and as a result little is known about how camelid diversity responded to climate and vegetation changes in the Pacific Northwest. Horses are a well-studied example of ungulate responses to climactic changes and grassland expansion . They show a general increase in body size that is concurrent with their switch from browsing to mixed feeding and eventually to the grazing we see in modern examples . I suspect that as the environment in the Pacific Northwest dried out, camelids also increased in size due to the grassland expansion . I also believe that camelids incorporated more grasses into their diet . I tested this by documenting camelid diversity in the Pacific Northwest, specifically the states of Idaho, Oregon, and Washington, using the published fossil occurrences on the Paleobiology Database . Body size data was estimated using tooth measurements collected on the Fossilworks database . Camelid species were categorized according to two ecological parameters, body size and diet . I used these to track camelid evolution through time . I found that although body mass does increase there were still small browsing lineages late into the Miocene . This study provides a broader biogeographical picture of how grassland expansion influenced camelid evolution and ecology .

New specimen of Monosaulax typicus (Mammalia, Castoridae) from the Mascall Formation of Twin Buttes in the Crooked River Basin, Oregon

Presenter(s): Shyla Davison—Earth Science

Faculty Mentor(s): Samantha Hopkins

Session 6: The Earth, Sky & Everything In Between

The Mascall formation of Central Oregon is a rock unit that was formed during the middle Miocene (~15 million years ago) . The Mascall formation was first described from North Central Oregon, but also outcrops to the south in the Crooked River Basin, where it is much older . While these southern outcrops of the Mascall Formation have been known for some time, recent research shows that they are about a million years older than the outcrops of the same formation in the John Day Basin . This particular formation is known for producing many Barstovian-age mammals . Recent collections by University of Oregon field crews have yielded new material from the Crooked River region . I have diagnosed two new specimens recovered from the Mascall formation from Twin Buttes near Paulina, OR, as Monosaulax typicus from the family Castoridae . One specimen is a fragment of a lower right jaw that contains the p4-m2, while the other is a left jaw fragment . These are the most complete remains of M . typicus from the Mascall formation; other known specimens are isolated teeth . The teeth have all the diagnostic characteristic of other previously identified specimens of M . typicus that were found in Southeast Oregon rocks of similar age (Shotwell, 1968) . The information of this new specimen will add to the limited knowledge of this species and the environment of the Crooked River Basin .

COVID-19, Climate Change, and Collages—A creative analysis disguised as an educational approach to inform about the connection between climate change and COVID-19.

Presenter(s): Alexandra Acosta-Torres—Earth Science

Co-Presenter(s):Jaemie Bynum

Faculty Mentor(s): Sarah Stoeckl, Kathyrn Lynch

Session 1: Environmental Leaders ARC

Being quarantined during the COVID-19 pandemic has left people in a state of desperation to fill their time with entertainment and fulfilling activities . The purposes of our project are to teach about the connections between COVID-19 and climate change and provide a video tutorial on how to make a meaningful collage . Collaging is an accessible, environmentally friendly type of upcycling that can fill that time . The research looks at scientific and social connections between climate change and COVID-19 . The collage created has a collection of themes regarding nature, the use of nature, loneliness, eco-grief, and the impacts of pollution, with the overall goal of visually symbolizing the impacts of climate change and COVID-19 . It is essential for the general public to understand the social and scientific connections between the impacts of climate change and COVID-19 because climate change requires social and scientific awareness in order to be resolved . We teach how to collage and challenge our audience to collage in our YouTube video . Our project aims to create a friendly activity that can be shared with friends while also generating interest in environmental issues and the current pandemic .