Tag: Earth Sciences

Geometric and Thermal Constraints on the Timing of Alaskan Tidewater Glacier Retreat

Presenter: Lucy Waghorn – Earth Sciences

Faculty Mentor(s): Dave Sutherland, Alex Hager

Session: (In-Person) Poster Presentation

Glaciers around the world are retreating at increasing rates, prompting concerns over sea level rise and the future of the cryosphere. In southern Alaska, some have retreated while their neighbors have advanced, indicating that local atmospheric conditions are not the only influence on glacial retreat. One possible factor is the interaction of ocean water with the glacier at the terminus. However, fjord geometry can alter the ocean water that interacts with the terminus, and the interaction of fjord geometry and ocean temperature anomalies has not been investigated in Alaska thus far. To investigate the interaction of fjord geometry and glacier retreat, we used bathymetry, air temperature (AT), sea surface temperature (SST), and terminus position data. Here we show that high SST anomalies may enhance glacial retreat in fjords with shallow sills. During a high SST anomaly, some glaciers in shallow-silled fjords retreated rapidly from a point of relative stability. Many glaciers also showed enhanced retreat in the two years after a high AT anomaly. It is possible that shallow sills influence fjord water circulation where only the warmest part of the water column can enter the near terminus region, potentially leading to enhanced glacier retreat after high SST anomalies. Though other factors can also contribute, understanding these processes and interactions that lead to glacier retreat is becoming increasingly important as climate change alters the atmosphere and environment.

Investigating Greywater Filtration Capabilities of Pumice and Scoria from the Pacific Northwest

Presenter: Margery Price – Earth Sciences

Faculty Mentor(s): Thomas Giachetti

Session: (In-Person) Poster Presentation

Graywater (wastewater produced by bathing, washing, and other domestic water uses) contains particles that can be removed by filtration. With treatment, it can be reused for tasks such as irrigation or street cleaning. Pumice and scoria, highly porous volcanic rocks, are optimal filtration media; they have both high external and internal surface area due to their tortuous networks of connected pores. This project investigates the physical characteristics of pumices and scoriae that most impact their efficacy as filter materials by testing interactions between the rocks and graywater. Samples of pumice and scoria from Oregon volcanoes are measured using a Particle Analyzer, a high precision scale, and a helium pycnometer to find mass, volume, packing fraction, and total and connected porosity. Graywater is created using conventional household cleaning and personal care products, then characterized for pH, turbidity, TDS, and conductivity. Lastly, static absorption experiments examine the interactions between pumice and scoria with both tap water and graywater when submerged. Preliminary results show that pumice and scoria systems of the same sizes absorb similar volumes of water, despite having different porosities. Scoria offers more area of interaction with water on its external surfaces, but pumice contains more available surface area within the particles. More work needs to be done investigating which of these parameters results in better filtration of graywater.

Stable Isotope Analysis of Fossil Shark Teeth from the Late Cretaceous Western Interior Seaway

Presenter: Rachel Lisle − Earth Sciences

Faculty Mentor(s): Edward Davis, Kellum Tate-Jones

Session: (In-Person) Poster Presentation

The Western Interior Seaway was a Late Cretaceous (100.5-66 mya) inland sea that, at it’s largest, stretched north to south, from the modern-day Arctic Ocean to the Gulf of Mexico. Research concerning the seaway has revealed that there was likely a significant temperature gradient present, with cooler temperate waters to the north and warmer subtropical waters to the south. Using fossilized teeth from two species of sharks collected from an Arkansas site associated with the Western Interior Seaway, I seek to use carbon and oxygen isotopes to interpret the paleoecological conditions present in the southern province of the seaway during the Late Cretaceous. I also seek to identify what conditions made it suitable for these sharks to live in this province. Using stable isotope analysis by way of laser ablation, as well as conducting a literature review on relevant sources, I have found that these sharks likely preferred the subtropical temperatures over cooler temperate waters. Mirroring this is a similar pattern in salinity, wherein these species likely preferred water with a higher salinity than the more brackish water up north. This research is essential in understanding what conditions made the seaway favorable for shark species and how extinct marine vertebrates interacted with and reacted to their environment.

Excluding numeric side-effect information produces lower vaccine intentions

Presenter: Eliza Lawrence – Earth Sciences

Faculty Mentor(s): Ellen Peters, Brittany Shoots-Reinhard

Session: (In-Person) Poster Presentation

Encouraging vaccine uptake is important to reducing the impact of infectious disease. However, negative attitudes and vaccine hesitancy, due in part to worry about side effects, are obstacles to achieving high vaccination rates. Provided vaccine information sheets typically include a list of side effects without numeric information about their likelihoods, but providing such numbers may yield benefits. We investigated the effect of providing numeric information about side-effect likelihood (“1%”) and verbal labels (“uncommon”) on intentions to get a hypothetical vaccine, reasons for the vaccination decision, and risk overestimation. In a diverse, online, convenience sample (N=595), providing numeric information increased vaccine intentions—70% of those who received numeric information were predicted to be moderately or extremely likely to vaccinate compared to only 54% of those who did not receive numeric information (p<.001), controlling for age, gender, race, education, and political ideology. Participants receiving numeric information were less likely to overestimate side-effect likelihood. Among the vaccine-hesitant, 43% of those provided numeric information and verbal labels were predicted to be moderately or extremely likely to get vaccinated vs. only 24% of those given a list of side effects (p<.001). We conclude that the standard practice of not providing numeric information about side-effect likelihood leads to a less-informed public who is less likely to vacci.

 

Thin section analysis to determine magma flow directions in a silicic dike at Summer Coon volcano

Presenter: Madeline Bruce − Earth Sciences

Faculty Mentor(s): Gui Aksit, Meredith Townsend

(In-Person) Poster Presentation

A significant number of people throughout the world live in areas with active volcanism, creating a geologic hazard to contend with. Stratovolcanoes pose a unique threat to nearby populations due
to their generally more explosive nature. Because dikes are volcanic plumbing systems responsible for transporting magma, studying the extinct Oligocene age stratovolcano, Summer Coon, provided meaningful data in understanding how dike systems propagate and how magma migrated as it approached the surface to erupt. A part of the San Juan Volcanic Complex in Southern Colorado, erosion and uplift has exposed the radial dike system at the surface where it can be studied. Previous work has been done on magma flow directions of basaltic/andesitic dikes of Summer Coon, but further work was needed for longer silicic dikes to recreate magma flow directions at the time of dike emplacement. Samples were taken from twelve locations along “Dike A” both at the center and margins of the dike. These samples were then made into thin sections, scanned into Photoshop and edited for size requirements. Using ImageJ, the thin sections were edited further to identify and isolate the minerals that showed shear. Various parameters were documented for each thin section using ImageJ and compiled into an excel document. Finally, statistical analysis was done to produce the resultant vector angle that represents the dominant direction of flow specific to each sample taken and to find the R-value.