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Full-Text Articles in Physical Sciences and Mathematics
Holocene Earthquakes And Right-Lateral Slip On The Left-Lateral Darrington-Devils Mountain Fault Zone, Northern Puget Sound, Washington, Stephen F. Personius, Richard W. Briggs, Alan R. Nelson, Elizabeth R. Schermer, J. Zebulon Maharrey, Brian L. Sherrod, Sarah A. Spaulding, Lee-Ann Bradley
Holocene Earthquakes And Right-Lateral Slip On The Left-Lateral Darrington-Devils Mountain Fault Zone, Northern Puget Sound, Washington, Stephen F. Personius, Richard W. Briggs, Alan R. Nelson, Elizabeth R. Schermer, J. Zebulon Maharrey, Brian L. Sherrod, Sarah A. Spaulding, Lee-Ann Bradley
Geology Faculty Publications
Sources of seismic hazard in the Puget Sound region of northwestern Washington include deep earthquakes associated with the Cascadia subduction zone, and shallow earthquakes associated with some of the numerous crustal (upper-plate) faults that crisscross the region. Our paleoseismic investigations on one of the more prominent crustal faults, the Darrington–Devils Mountain fault zone, included trenching of fault scarps developed on latest Pleistocene glacial sediments and analysis of cores from an adjacent wetland near Lake Creek, 14 km southeast of Mount Vernon, Washington. Trench excavations revealed evidence of a single earthquake, radiocarbon dated to ca. 2 ka, but extensive burrowing and …
Hydroacoustic Investigations Of Submarine Landslides At West Mata Volcano, Lau Basin, Jacqueline Caplan-Auerbach, R. P. Dziak, D. R. Bohnenstiehl, W. W. Chadwick, T. -K. Lau
Hydroacoustic Investigations Of Submarine Landslides At West Mata Volcano, Lau Basin, Jacqueline Caplan-Auerbach, R. P. Dziak, D. R. Bohnenstiehl, W. W. Chadwick, T. -K. Lau
Geology Faculty Publications
Submarine landslides are an important process in volcano growth yet are rarely observed and poorly understood. We show that landslides occur frequently in association with the eruption of West Mata volcano in the NE Lau Basin. These events are identifiable in hydroacoustic data recorded between ~5 and 20 km from the volcano and may be recognized in spectrograms by the weak and strong powers at specific frequencies generated by multipathing of sound waves. The summation of direct and surface-reflected arrivals causes interference patterns in the spectrum that change with time as the landslide propagates. Observed frequencies are consistent with propagation …
Multiple Migmatite Events And Cooling From Granulite Facies Metamorphism Within The Famatina Arc Margin Of Northwest Argentina, Sean R. Mulcahy, Sarah M. Roeske, William C. Mcclelland, Joshua R. Ellis, Fred Jourdan, Paul R. Renne, Jeffrey D. Vervoort, Graciela I. Vujovich
Multiple Migmatite Events And Cooling From Granulite Facies Metamorphism Within The Famatina Arc Margin Of Northwest Argentina, Sean R. Mulcahy, Sarah M. Roeske, William C. Mcclelland, Joshua R. Ellis, Fred Jourdan, Paul R. Renne, Jeffrey D. Vervoort, Graciela I. Vujovich
Geology Faculty Publications
The Famatina margin records an orogenic cycle of convergence, metamorphism, magmatism, and extension related to the accretion of the allochthonous Precordillera terrane. New structural, petrologic, and geochronologic data from the Loma de Las Chacras region demonstrate two distinct episodes of lower crustal migmatization. The first event preserves a counterclockwise pressure-temperature path in kyanite-K-feldspar pelitic migmatites that resulted in lower crustal migmatization via muscovite dehydration melting at ∼12 kbar and 868°C at 461 ±1.7 Ma. The shape of the pressure temperature path and timing of metamorphism are similar to those of regional midcrustal granulites and suggest pervasive Ordovician migmatization throughout the …
Izu-Bonin-Mariana Rear Arc: The Missing Half Of The Subduction Factory, Yoshihiko Tamura, Abigail K. Barker, Cathy J. Busby, Julien L.R. Berger, Peter Blum, Everton M. Bongiolo, Gilles Guèrin, Manuela Bordiga, Graham D.M. Andrews, Susan M. Debari, James B. Gill, Cedric Hamelin, Jihui Jia, Eleanor H. John, Ann-Sophie Jonas, Martin Jutzeler, Myriam A.C. Kars, Zachary A. Kita, Kevin Konrad, Susan H. Mahony, Michelangelo Martini, Takashi Miyazaki, Robert J. Musgrave, Debora B. Nascimento, Alexander R.L. Nichols, Julia M. Ribeiro, Tomoki Sato, Julie C. Schindlbeck, Axel K. Schmitt, Susanne M. Straub, Maryline J. Vautravers, Yang Yang
Izu-Bonin-Mariana Rear Arc: The Missing Half Of The Subduction Factory, Yoshihiko Tamura, Abigail K. Barker, Cathy J. Busby, Julien L.R. Berger, Peter Blum, Everton M. Bongiolo, Gilles Guèrin, Manuela Bordiga, Graham D.M. Andrews, Susan M. Debari, James B. Gill, Cedric Hamelin, Jihui Jia, Eleanor H. John, Ann-Sophie Jonas, Martin Jutzeler, Myriam A.C. Kars, Zachary A. Kita, Kevin Konrad, Susan H. Mahony, Michelangelo Martini, Takashi Miyazaki, Robert J. Musgrave, Debora B. Nascimento, Alexander R.L. Nichols, Julia M. Ribeiro, Tomoki Sato, Julie C. Schindlbeck, Axel K. Schmitt, Susanne M. Straub, Maryline J. Vautravers, Yang Yang
Geology Faculty Publications
4GT) lies in the western part of the Izu fore-arc basin, ~60 km east of the arc-front volcano Aogashima, ~170 km west of the axis of the Izu-Bonin Trench, 1.5 km west of Ocean Drilling Program (ODP) Site 792, and at 1776 meters below sea level (mbsl). It was drilled as a 150 m deep geotechnical test hole for potential future deep drilling (5500 meters below seafloor [mbsf]) at proposed Site IBM-4 using the D/V Chikyu. Core from Site U1436 yielded a rich record of Late Pleistocene explosive volcanism, including distinctive black glassy mafic ash layers that may record large-volume …
Crustal Shortening, Exhumation, And Strain Localization In A Collisonal Orogen: The Bajo Pequeno Shear Zone, Sierra De Pie De Palo, Argentina, Joshua M. Garber, Sarah M. Roeske, Jessica Warren, Sean R. Mulcahy, William C. Mcclelland, Lauren J. Austin, Paul R. Renne, Graciela I. Vujovich
Crustal Shortening, Exhumation, And Strain Localization In A Collisonal Orogen: The Bajo Pequeno Shear Zone, Sierra De Pie De Palo, Argentina, Joshua M. Garber, Sarah M. Roeske, Jessica Warren, Sean R. Mulcahy, William C. Mcclelland, Lauren J. Austin, Paul R. Renne, Graciela I. Vujovich
Geology Faculty Publications
The Bajo Pequeño Shear Zone (BPSZ) is a lower-crustal shear zone that records shortening and exhumation associated with the establishment of a new plate boundary, and its placement in a regional structural context suggests that local- to regional-scale strain localization occurred with progressive deformation. A kilometer-scale field and analytical cross section through the ~80 m thick BPSZ and its adjacent rocks indicates an early Devonian (405–400 Ma) phase of deformation on the western margin of Gondwanan continental crust. The earliest stages of the BPSZ, recorded by metamorphic and microstructural data, involved thrusting of a hotter orthogneiss over a relatively cool …
Age, Origin, And Tectonic Evolution Of The Yellow Aster Complex: Northwest Washington State, Eric A. (Eric Adam) Hoffnagle
Age, Origin, And Tectonic Evolution Of The Yellow Aster Complex: Northwest Washington State, Eric A. (Eric Adam) Hoffnagle
WWU Graduate School Collection
The Yellow Aster Complex in northwest Washington is a basement portion of the Chilliwack composite terrane and appears throughout the western foothills of the North Cascades as fault bounded tectonic blocks (Brown, 1987; Brown et al. 2010). This study was undertaken in part to refine and understand the significance of the depositional, magmatic, and metamorphic history of the Yellow Aster Complex. Field work and petrographic analyses reveal that the Yellow Aster Complex consists of calc-silicate and quartzo-feldspathic paragneisses with minor amounts of marble and quartzite. Leucocratic and mafic intrusions are also present throughout the terrane. Zircons from six Yellow Aster …
A Geochemical Study Of The Riddle Peaks Gabbro, North Cascades: Evidence For Amphibole Accumulation In The Mid-Crust Of An Arc, Angela C. Cota
A Geochemical Study Of The Riddle Peaks Gabbro, North Cascades: Evidence For Amphibole Accumulation In The Mid-Crust Of An Arc, Angela C. Cota
WWU Graduate School Collection
Mid-crustal arc rocks are not commonly exposed, hampering our understanding of magma differentiation processes and mineral crystallization in the mid-crust of arc systems. This thesis presents results of the study of one exposed mid-crustal arc pluton, which is a unique laboratory to understand the geochemical effects of crystallization in this type of system. I report on the major and trace element characteristics of amphibole, plagioclase, and apatite in hornblendite and hornblende gabbro cumulates from the ~44 km2 Riddle Peaks pluton (~77 Ma) in the North Cascades Crystalline Core (NCCC), Washington. Electron microprobe and laser ablation-induced mass spectrometry (LA-ICP-MS), coupled with …
Estimating Sediment Yield From The Swift Creek Landslide, Whatcom County, Washington State, Curtis R. Clement
Estimating Sediment Yield From The Swift Creek Landslide, Whatcom County, Washington State, Curtis R. Clement
WWU Graduate School Collection
The amount of suspended sediment carried by streams in mountainous watersheds is an important factor in environmental and engineering planning, especially when the material happens to be of toxic nature. The Swift Creek watershed contains a deep-seated landslide composed of weathered serpentinite, which includes chrysotile (capable of asbestiform morphology), chlorite, illite, and hydrotalcite. The United States Environmental Protection Agency has determined that the asbestiform material contains particles of sufficient size and quantity that could be hazardous to human health. The suspended sediment load from Swift Creek is primarily influence by the steep, disturbed and unvegetated toe of the landslide which …
Quantifying Submarine Eruptive Flux From Interpretation Of Hydroacoustic Signals, West Mata Volcano, Lau Basin, Chelsea J. (Chelsea Joy) Mack
Quantifying Submarine Eruptive Flux From Interpretation Of Hydroacoustic Signals, West Mata Volcano, Lau Basin, Chelsea J. (Chelsea Joy) Mack
WWU Graduate School Collection
West Mata is a submarine volcano in the northeast Lau Basin. Hydroacoustic data from a 5-month period provide insight into the nature of eruptive behavior at this volcano. Previous studies have used acoustic data to estimate the eruption velocity at subaerial volcanoes (Woulff and McGetchin, 1976; Vergniolle et al., 2004; Vergniolle and Caplan- Auerbach, 2004, 2006; Caplan-Auerbach et al., 2010). In this study, the hydroacoustic data from West Mata are used to calculate eruption velocities and volumes (both lava and gas) for explosions during the 5-month hydrophone deployment. The method used in this study, developed by Vergniolle and Caplan-Auerbach (2006), …
Sediment And Phosphorus Inputs From Perennial Streams To Lake Whatcom, Northwestern Washington State, Katherine Beeler
Sediment And Phosphorus Inputs From Perennial Streams To Lake Whatcom, Northwestern Washington State, Katherine Beeler
WWU Graduate School Collection
Nutrient enrichment presents a common problem in lakes and streams by promoting algae growth and the depletion of dissolved oxygen. Lake Whatcom in northwestern Washington State is subject to a Total Maximum Daily Load (TMDL) to limit phosphorus input. The 20-km2 lake is supported by runoff from numerous perennial streams in a steep, 125-km2, moderately developed, forested watershed. Much of the phosphorus entering the lake is adsorbed to suspended sediment in streams and is transported to the lake during storm events. Understanding sediment and phosphorus transport to the lake is important for managing the TMDL and for maintaining water quality …
Effectiveness Of Time-Lapse Videos As A Method To Teach Rates Of Surface Geological Processes, Zachary P. Schierl
Effectiveness Of Time-Lapse Videos As A Method To Teach Rates Of Surface Geological Processes, Zachary P. Schierl
WWU Graduate School Collection
Understanding the wide range of rates at which geological processes operate can be challenging for introductory geology students, and yet is crucial to understanding how the Earth’s landscapes evolve over time. Research has shown that student misconceptions in this area are common. Time-lapse videos can capture processes that cannot be observed by students in the field and offer promise as a way to improves student understanding of rates of landscape evolution on certain timescales. This thesis explores the effectiveness of using time-lapse videos to teach intro geology students about the rates of surficial geological processes compared to before/after photo pairs …
High-Resolution Lidar Mapping And Analysis To Quantify Surface Movement Of Swift Creek Landslide, Whatcom County, Wa, Benjamin R. Ferreira
High-Resolution Lidar Mapping And Analysis To Quantify Surface Movement Of Swift Creek Landslide, Whatcom County, Wa, Benjamin R. Ferreira
WWU Graduate School Collection
I investigated the applicability of using terrestrial laser scanning (TLS) to quantify surface displacement of the Swift Creek landslide, an active earth flow in the foothills of northwest Washington State. Five surveys were completed from October, 2009-April, 2011 to identify and measure spatial and temporal changes in the movement of the landslide. The seasonally variable movement patterns at the site provide an ideal environment to test the effectiveness of newly emerging methods to measure surface displacement. Iterative closest point (ICP) analysis and image cross-correlation via particle image velocimetry (PIV) were applied to sequential TLS datasets to identify and match features …
Magnetostratigraphy And Block Rotation Of The Mecca Hills, Ca, Graham T. (Graham Thomas) Messe
Magnetostratigraphy And Block Rotation Of The Mecca Hills, Ca, Graham T. (Graham Thomas) Messe
WWU Graduate School Collection
The sedimentary Palm Spring Formation crops out in the Mecca Hills, CA and preserves valuable information about the evolution of the San Andreas fault system in the transtentional Salton Trough. Constraining the timing of deposition for the Palm Spring Formation upper unit is useful for estimating timing of basin development due to fault motions. Magnetostratigraphic correlation is used as the most viable means of dating this sequence because the unit lacks well constrained age indicative fossils and strata. Paleomagnetic analysis is also used to constrain the amount of vertical axis rotation that the region has undergone within the southern San …