Over the last few years, there has been a dramatic increase in wildfires and their severity. Wildfire is a natural phenomenon that needs to happen to regenerate life within ecosystems. It kills off the old growth, allowing new growth to flourish in its place. Previously, scientists and political officials understood wildfire as an enemy of the forest, partly because forests were valued as commodities. Wildfire has its benefits but has devastating affects on communities. This study examines wildfire in the wilderness urban interface (WUI) within the Cascades Mountain Range, Washington. This study has three parts. First, I mapped the WUI over two decades in the Cascades Mountain Range, Washington. Second, I created a spatial index to depict risk levels across the study area. Last, I met with stakeholders to understand the current practices of wildfire fighting and the needs of the community. This research found significant growth in the WUI, interesting variation in wildfire risk across the Cascades, and conflicting interests among the stakeholders, ranging from privileging forest ecology to valuing the economy. These insights were gained by using geospatial techniques. Wildfires aren’t going away, and we need to understand how communities will be impacted and can prepare for the future.

 The Cascades mountains of the Pacific Northwest are highly vulnerable to the impacts of climate change, and increases in temperature have led to decreased snow and an uncertain future. A reduced snowpack has significant ramifications for the evolving ski and backcountry Winter recreation industry in Washington state. My research considers a changing natural landscape and its hydrological processes in the face of global climate change, from the lens of backcountry recreation. I use geospatial analysis to quantify the extent to which the snowpack of the Cascades has been impacted by temperature increases using data from snowpack telemetry sites and remotely sensed hydrologic data, and models its future state given predicted climate scenarios. I discuss the dynamics of winter backcountry recreation including increased usage, the effects of the COVID-19 pandemic, avalanche awareness and risk, and the existential threat to Pacific Northwest Winter recreation when mountain snowfall becomes rain.

From 2004 to 2018 the Centers for Disease Control and Prevention recorded an average of 702 deaths per year in the United States related to excessive heat events. With more of the world’s population now living in cities, understanding the urban heat island effect and its impact on morbidity and mortality is increasingly important. In the US, the intensity of the urban heat island effect is well known in Atlanta, GA. As part of a team, I examined the extent to which ground cover affects the minimum, maximum, and average temperatures in Atlanta compared to its surrounding neighborhoods. Temperature data reported by weather stations was gathered at varying distances from downtown, and cross-referenced to a map of the land cover in Atlanta to find that temperatures varied greatly as the distance from downtown increased. Overall, it was found that minimum temperatures varied more than average or maximum temperatures, and of all the ground cover types studied, more urbanization contributed to warmer temperatures. This study builds on these findings by introducing the coarse-grained urban heat island model constructed by Gabriele Manoli and colleagues at ETH Zurich which considers factors beyond just ground cover. By applying the Manoli, et al, computational model to Atlanta Georgia I can further examine the urban heat Island effect in that region, and explore the patterns observed in previous findings. The implications of this model stretch far beyond Atlanta Georgia to help form geographically targeted guidelines for urban centers for which extensive research has not been done to understand temperature trends.

Since its discovery, graphene has become a prominent material of interest for advanced bioelectronic and biomedical applications such as diagnostics, drug delivery, and imaging. This two-dimensional atomically thin sheet of sp2 hybridized carbon has exceptional electronic properties and is well suited for the development of highly sensitive and selective biosensors when paired with biomolecular adlayers. Additionally, by controlling the biomolecular orientation, conformation, and assembly structure of the adlayer, device functionality and performance can be fine-tuned. In this work, we focus on the conformational properties of three graphene-binding peptides, GrBP5-WT, GrBP5-M2 and Truncated GrBP5-M2, that form strongly adhered self-assembled adlayers at graphene surfaces. While these peptides are chemically very similar, experimental observations revealed they demonstrate opposite assembly phenomena upon thermal stimulus. Herein, enhanced sampling molecular dynamics simulations were employed using GROMACS simulation package with the PLUMED plugin to unravel how specific peptide conformations lead to the unexpected assembly behavior. Self-assembling peptide conformations were identified by comparing their computationally derived binding energies to experimental energetic data obtained from a scanning probe microscopy based molecular energetic analysis. The self-assembly structure of peptide on the graphene surface could form a module on the biosensor and used to detect specific proteins or peptides. With a better understanding of the peptide self-assembly mechanism, it would be significant to the development of biosensor.

The island of La Palma is the second youngest in the Canary Island volcanic chain, 475km northwest of Africa, which was created by hot spot magmatism. The earliest activity of each volcano erupted below sea level and was later buried by subaerial eruptions. On the island of La Palma, the seamount, or submarine-building stage of the Taburiente volcano, is uniquely exposed due to uplift and a subsequent giant landslide that exposed the interior of the volcano. It provides access to basalts that record the island’s early magmatic history. I report lead, hafnium, and strontium isotopes of Taburiente’s submarine history in order to infer the mantle origin of the magma source and compare the data to that of the later subaerial volcanic rocks to determine if magma source changes occurred between the two volcanic phases. Each analyzed rock sample was divided in two parts: one was acid-leached to remove possible contamination and alteration caused by hot seawater circulating through rock on the ocean floor and the other was not acid-leached. Both sample sets were then dissolved in strong acids to collect pure Pb, Hf, and Sr aliquots using ion-exchange chemistry and isotopically analyzed using high-precision mass spectrometry. The isotopic ratios of ocean island basalts in general differ greatly from ocean floor basalts. This is the basis for determining if Taburiente’s early volcanic phase is more similar to an ocean floor or an ocean island basalt composition. The data also detail the type of mantle source—whether primordial or recycled rock that was returned from the surface back into the mantle. The leached versus non-leached sample sets quantify how much hydrothermal alteration has occurred within the seamount and if this is a useful technique to apply to future studies of ocean island basalts.