Physical Sciences and Mathematics Commons^™

To Erupt Or Not To Erupt? That Is The Question: Extremely High Levels Of Background Seismicity And Lack Of Eruptivity From 2003-2019 At Gareloi Volcano, Aleutian Islands, Alaska, Kiana Tamarie Harris

WWU Graduate School Collection

Mount Gareloi, one of the westernmost volcanoes in the Aleutian arc, has not erupted since 1989, yet it continuously exhibits extremely high levels of background seismicity. Hundreds of volcanic earthquakes are recorded per day on the island since seismometer installation in 2003. I analyzed and classified seismic data collected from 2003-2019 to explore the geophysical processes causing this consistent seismicity with no subsequent eruptive activity. Analysis of waveform and corresponding spectra indicate the vast majority of Gareloi earthquakes are characterized by frequencies between 1 and 5 Hz, which are typical of long-period (LP) events, and these events are particularly dominant …

Geochemical Investigation Of Monogenetic Volcanoes From The Pribilof Islands, Bering Sea, Alaska, Clayton L. Reinier

MSU Graduate Theses

Small-volume basaltic magmas found at continental intraplate environments have not been as extensively studied compared to their polygenetic counterparts. Specifically, regions such as the Bering Sea basalt province, described as a diffuse igneous province, have commonly been overlooked. Assumptions that these systems are invoked by simple, single batches of magma has subsequently left a gap in understanding the processes responsible for primary magma generation away from plate boundaries with little tectonic influence. The following studies that constitute this thesis focus on an in-depth geochemical investigation at the crystal and sub-crystal scale to evaluate lithospheric mantle heterogeneities, processes that govern primary …

Assessing The Accuracy Of A Uav Snow Depth Survey: Utqiagvik (Barrow), Alaska Calm Grid, Ian Nichols

Dissertations, Master's Theses and Master's Reports

Active layer depth and snow depth are annually collected across the Circumpolar Active Layer Monitoring (CALM) Network to observe the response of the active layer and near-surface permafrost to climate change over decadal-time scales. Snow depth is typically measured using a graduated steel probe at each grid node but, in this paper, we explore the viability of using Unmanned Aerial Vehicle (UAV) (drone) technology to collect snow depth measurements at the 1 km² Utqiagvik (Barrow), Alaska CALM grid. This is achieved by comparing estimated UAV snow depths to measured snow depths collected using a MagnaProbe (MP) at each of …

Structural Style And Stratigraphic Architecture Of The Northeastern Brooks Range, Alaska, Benjamin G. Johnson

Graduate Theses, Dissertations, and Problem Reports

The Arctic Alaska–Chukotka microplate is a large Mesozoic–Cenozoic composite terrane that resides at the northern limit of the North American Cordillera. Although its Mesozoic origins are assuredly linked to the opening of the Amerasian Basin of the Arctic Ocean, its Paleozoic origins can be linked to at least three separate paleocontinents, including northern Laurentia, Baltica, and Siberia. Across the Arctic Alaska portion of the microplate, an internal, mid-Paleozoic suture zone presumably separates rocks of the North Slope subterrane (Laurentian affinity) from a collection of smaller subterranes in the southern Brooks Range and Seward Peninsula (Baltic affinity).

The mountains of the …

Understanding And Developing Estimates Based On Practical Foundation Methods For Alaska's Discontinuous Permafrost Region, Paul P. Dennison

Theses and Dissertations

This research uses a quantitative analysis to develop a family of curves and a calculator for potential foundation thresholds in the discontinuous permafrost region of Alaska. The United States Pacific Command (PACAF) is bolstering the region by advocating for the F-35, KC-46, and the newly proposed long-range bomber to be stationed in Alaska. These next generation aircrafts and warfighters will need new facilities and beddown plans to efficiently and effectively carry out their mission. The biggest obstacle in the region is permafrost; this unique polar phenomenon is found throughout the northern half of Alaska. Fairbanks in particular has multiple military …

Paleodrainage Insights Into The Fluvial And Glacial History Of The Western Chukchi Margin, Arctic Alaska, Brittany A. Stockmaster

Electronic Theses and Dissertations

Chirp subbottom data collected from the Chukchi shelf, offshore of northwest Alaska, revealed extensive paleodrainage networks that incised the margin during sea level lowstands. These features are cut into folded Cretaceous bedrock strata and represent multiple sea level cycles. Several large incised valleys, 10s of km wide and up to 54 m deep, as well as numerous smaller, individual channels were identified. Sources of fluvial input include several, smaller rivers on the northwest Alaskan coast, such as the Kokolik, Kuk, Kukpowruk, and the Utukok Rivers. Correlation of sediment infill patterns provided insight to paleochannels and paleovalleys as well as outlined …

Paleoenvironmental Analysis Of Cretaceous Mudstones At Slope Mountain, Alaska Using Carbon Stable Isotopes, Ashley Ratigan

Honors Papers

This project uses field samples, microfacies analysis, and carbon stable isotopes of mudstones to determine past environmental conditions of North Slope, Alaska during the Albian-Cenomanian (Cretaceous). Samples were taken at Slope Mountain, Alaska located north of the Brooks Range. Slope Mountain includes the Torok Formation and the upper and lower Nanushuk Formations that consist of alluvial, deltaic, and shallow marine facies that were deposited into the North Slope foreland basin on the Arctic Alaska micro plate. An exhaustive search for identifiable microfossils, such as pollen, diatoms, and foraminifera in the samples yielded nothing but charcoal and carbon residue. No other …

Field Observations And Modeling Of The 1957 Earthquake And Tsunami On The Islands Of The Four Mountains, Aleutian Islands, Alaska, Frances R. Griswold

All Master's Theses

Due to a lack of research in the Aleutian Islands, a comprehensive history of the Aleutian subduction zone is not developed; however, this study indicates that the Aleutian subduction zone is capable of generating magnitude ~9 earthquakes or larger in addition to trans-Pacific tsunamis. Comparison of simulated runup and observed runup will help to determine the characteristics of rupture in the eastern Aleutians. A recent survey of the tsunami wrackline produced by the 1957 Great Aleutian earthquake (M_w 8.6) indicates runup up to 17.5 m in the Islands of the Four Mountains (presented here). Combined with other nearfield observations …

Modern To Late Pleistocene Stable Isotope Climatology Of Alaska, Alison Sloat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding modern controls on climate is necessary to interpret past climatic conditions. This project investigated the modern controls on δ18O and δD values in Alaskan surface waters to interpret the controls on Late Pleistocene climate variability. ArcGIS was used to develop an isoscape of modern δ18O and δD values of over 400 surface water samples collected across Alaska and the Yukon. It was found that winter temperature and precipitation have the greatest controls on δ18O and δD values in Alaska, resulting in high δ18O values along the coast of the Gulf of Alaska and low values inland toward Central Alaska. …

Structural And Geochronologic History Of Southern Alaskan Blueschists, Erik M. Day

Open Access Theses & Dissertations

Detrital zircon data are presented from the Liberty Creek blueschist in the central Chugach Mountains which indicate two distinct periods of the preservation of blueschist facies metamorphism along the southern Alaskan margin. A maximum depositional age of ~136 Ma demonstrates that the Liberty Creek schist was deposited long after the Jurassic cooling ages (196-185 Ma; Lopez-Carmona et al., 2011) recorded in western Alaskan blueschist bodies, revealing two blueschist preservation events. This Early Cretaceous depositional age also indicates that there have been major reorganizations within this subduction complex because the Potter Creek assemblage, directly south of the Liberty Creek schist, is …

Constraints On The Structure Of The Border Ranges Fault System, South-Central Alaska From Integrated 3d Inversion Of Gravity/Magnetic Data, Niti Mankhemthong

Open Access Theses & Dissertations

I use updated gravity data, available aeromagnetic data, and other geophysical information as constraints to develop 2D and 3D structural models of density and magnetic susceptibility to better locate and determine the shape of the Border Ranges fault system (BRFS), the Border Range ultramafic and mafic assemblages and other forearc-arc boundary structures in south-central Alaska, that have previously been studied in only limited detail. There are three geophysical research projects that form the chapters of the dissertation. First, I estimated near-surface density variations in the central Kenai Peninsula based on the adaptation of the Nettleton (1939)-Parasnis (1952) method using Tarantola …

Seismological Studies In South-Central Alaska And Northern Mexico, Oscar Mario Romero De La Cruz

Open Access Theses & Dissertations

The work in this study is focused on two different areas, south-central Alaska and northern Mexico. In the first study area, I calculated dynamic stress drops for moderate sized earthquakes and performed receiver function analyses. The goal of the stress drop studies was to determine if events occurring within the more strongly coupled portion of the subducting slab have higher stress drops. My results shows that higher stress drops correspond to the locked and strongly coupled region in Prince William Sound, and lower stress drops are associated with the Cook Inlet region, a zone of relaxation of the plate interface. …

Structural And Tectonic Investigation Of A Transpressional System, Chugach Metamorphic Complex, Southern Alaska, Mitchell Ryan Scharman

Open Access Theses & Dissertations

Late Cretaceous to Eocene ridge subduction beneath the Mesozic Chugach terrane accretionary complex resulted in the formation of the Chugach metamorphic complex, and anomolus near trench plutonism of the Sanak-Baranof plutonic belt. The Chugach metamorphic complex (CMC), southern Alaska, is a high-temperature/low-pressure metamorphic belt, that offers a down plunge view of the mid- to lower-crust of a dextral transpression system. A distinct progression of deformation is recognized in the complex: 1) D1 contraction throughout the Chugach accretionary complex, 2) D2 margin parallel extension and horizontal simple shear, associated with subduction of higher ridge topography, followed by 3) D3 dextral transpression …

Provenance Signature Of A Forearc Basin Modified By Spreading Ridge Subduction: Detrital Zircon Geochronology And Detrital Modes From The Paleogene Arkose Ridge Formation, Southern Alaska, Cullen Kortyna

Honors Theses

Upper Paleocene–Eocene boulder conglomerate, cross-stratified sandstone, and laminated carbonaceous mudstone of the Arkose Ridge Formation exposed in the southern Talkeetna Mountains record fluvial-lacustrine deposition proximal to the volcanic arc in a forearc basin modified by Paleogene spreading ridge subduction beneath southern Alaska. U-Pb ages of detrital zircon grains and modal analyses were obtained from stratigraphic sections spanning the 2,000 m thick Arkose Ridge Formation in order to constrain the lithology, age, and location of sediment sources that provided detritus. Detrital modes from 24 conglomerate beds and 54 sandstone thin sections aredominated by plutonic and volcanic clasts and plagioclase feldspar with …

Feasibility Of Extending An Artificial Salmon Spawning Stream, Marx Creek Near Hyder, Alaska, Tom Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Marx Creek, near Hyder in southeast Alaska, is a groundwater-fed, artificial salmon-spawning stream that was constructed to enhance the habitat of the atypically large chum salmon. The success of the upper Marx Creek has been limited primarily by the infiltration of silty water from the Salmon River through its flood-control dike, which results in a turbid stream environment that is not conducive to salmon spawning.

The purpose of this project was to determine whether baseflow from the groundwater system is sufficient to support a proposed 1,000-foot extension of Marx Creek. The extension would be constructed approximately 500 feet east of …

Holocene Tephrostratigraphy, Southern Kenai Peninsula, Lower Cook Inlet, Alaska, Kathleen J. Lemke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis describes the results of a study of 33 tephra layers found within two peat sections near Anchor Point and Homer, Alaska, on the lower Kenai Peninsula. Numerous lower Cook Inlet volcanoes have been active through the Holocene. Tephra layers found at these two sites provide a partial record of their eruptive activity. The hazards that accompany this activity have increased as populations and commercial activities expand and air traffic over the region increases. The tephras analyzed for this study provide an initial geochemical database for the lower Cook Inlet volcanoes. The database is available in electronic format at …

Pre-Late-Wisconsin Glacial History Of The Naknek River Valley, Southwestern Alaska, Caleb H. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The lower Naknek River in southwestern Alaska dissects thick (~20m) exposures of Pleistocene glaciogenic sediments. The stratigraphy of the deposits and their physical, geochemical, mineralogical, and geochronological properties were studies to determine the number and timing of glacial advances represented. Multivariate data reduction methods (cluster and principal component analyses) were applied to the data to differentiate diamicton beds. The results show a clear separation of drift of the lower Naknek River valley from drift of northern Bristol Bay and from younger, moraine-comprising drift up valley. Within the Naknek River valley, however, there is no stratigraphic trend to the clusterings. The …

Late Quaternary Glacial Geology, Shoreline Morphology, And Tephrochronology Of The Lliamna/Naknek/Brooks Lake Area, Southwestern Alaska, Karen B. Stilwell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study focuses on the late-Wisconsin Brooks Lake glaciation, lake-level fluctuations, and volcanic deposits in the lliamna/Naknek/Brooks Lake area on the northern Alaska Peninsula, southwestern Alaska. The Brooks Lake glaciation consists of five stades, from youngest to oldest: Kvichak, Iliamna, Newhalen, Iliuk, and Ukak. This thesis reassigns the type Mak Hill moraine to a pre-late-Wisconsin glaciation, and considers the moraine enclosing Naknek Lake an early-late-Wisconsin deposit correlative to either the Kvichak stade, lliamna stade, or both. The presence in the Iliamna Lake valley, and the absence in the Naknek Lake valley of a two-fold earliest-late-Wisconsin Kvichak/Iliamna glacial sequence suggest that …

Geology And Ore Deposits Of The Salt Chuck-Rush And Brown Mine Area Prince Of Wales Island, Alaska, Judson H. Whitman

Bachelors Theses and Reports, 1928 - 1970

The Salt Chuck, Rush and Brown, and adjacent mines and claims form an area of approximately 15 square miles near the head of Kasaan Bay about 10 miles northwest of the village of Kasaan on Prince of Wales Island in southeastern Alaska. It is an area of moderate relief in which the hills rise from the water’s edge to heights of some 500 feet. Most of the area is covered with dense vegetation and muskeg.