Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
- Publication
- Publication Type
Articles 1 - 10 of 10
Full-Text Articles in Physical Sciences and Mathematics
Using Clinopyroxene Mineral Chemistry To Decipher Magma Composition Changes Over The 13 Million Year History Of The Izu-Bonin Volcanic Arc, Erin Benson
Geology Graduate and Undergraduate Student Scholarship
International Ocean Discovery Program Expedition 350 recovered 2000 meters of volcanic rock core in spring, 2014 at the Izu-Bonin-Mariana Rear Arc. The core has been divided into seven lithostratigraphic units, from age 0 at the top to at least 13 million years at the bottom. The major and trace element geochemistry of representative mineral grains in volcaniclastic rocks throughout the core from top to bottom were analyzed and used as a proxy for interpreting magma compositional changes through time. The clinopyroxene from all units and the glass from Unit I were analyzed for major elements (by SEM and electron microprobe) …
Surface Slip During Large Owens Valley Fault Earthquakes, Elizabeth K. Haddon, Colin B. Amos, O. Zielke, A. S. Jayko, R. Bürgmann
Surface Slip During Large Owens Valley Fault Earthquakes, Elizabeth K. Haddon, Colin B. Amos, O. Zielke, A. S. Jayko, R. Bürgmann
Geology Faculty Publications
The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross‐correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) …
Using Clinopyroxene Mineral Chemistry To Decipher Magma Composition Changes Over 13 Million Years In The Izu-Bonin Volcanic Arc, Erin Benson, Brian Rusk, Ricardo Escobar, Luan Heywood
Using Clinopyroxene Mineral Chemistry To Decipher Magma Composition Changes Over 13 Million Years In The Izu-Bonin Volcanic Arc, Erin Benson, Brian Rusk, Ricardo Escobar, Luan Heywood
Scholars Week
International Ocean Drilling Program (IODP) Expedition 350 drilled into the relatively unexplored rear arc of the Izu-Bonin-Mariana system (see map). It recovered 2000 meters of volcanic rock core in the spring of 2014. The core has been divided into seven lithostratigraphic units, from age 0 at the top to at least 13 million years at the bottom. I analyzed the major and trace element geochemistry of representative clinopyroxene and glass (in Unit I) and just clinopyroxene (in all other units) in volcaniclastic rocks throughout the core from top to bottom and used them as a proxy for interpreting magma compositional …
A Holocene Glaciolacustrine Record Of The Lyman Glacier And Implications For Glacier Fluctuations In The North Cascades, Washington, Harold N. Wershow
A Holocene Glaciolacustrine Record Of The Lyman Glacier And Implications For Glacier Fluctuations In The North Cascades, Washington, Harold N. Wershow
WWU Graduate School Collection
The Holocene glacial history of the North Cascades is poorly understood, in part because most existing records rely on moraine remnants and are therefore discontinuous. To develop a more complete record of Holocene fluctuations of North Cascades glaciers, we collected and analyzed glaciolacustrine sediments (i.e., rock flour) deposited over the past ~7800 years in Lyman Lake by the upstream Lyman Glacier. We combined these results with equilibrium-line altitude (ELA) reconstructions and glacier-climate modeling to quantify the climatic conditions that drove these fluctuations. Finally, we compared the Lyman Glacier’s continuous fluctuation record to existing glacier and climate records of the North …
Mechanisms Of Inverted Seismic Multiplets, Joel Brann
Mechanisms Of Inverted Seismic Multiplets, Joel Brann
WWU Graduate School Collection
In seismology, multiplets are a series of earthquakes with similar waveforms that are thought to represent a repeating process occurring at the same location. A few studies have previously identified multiplets with waveforms that are inverted relative to one another; here termed inverted multiplets (IMs).For this study, several data sets were searched for additional examples of IMs, including earthquake swarms associated with a volcanic eruption (Mt. Spurr), a dike intrusion (Nechako Basin), dome building (Mt. St. Helens), and times of no volcanic or magmatic activity (Piton de la Fournaise [PDLF], Mt. Spurr). Source mechanisms are determined to describe what could …
Fluvial Incision, Upper Plate Faulting, And Short-Term Deformation In The Southern Olympic Mountains Of Washington State, Jaime Delano
Fluvial Incision, Upper Plate Faulting, And Short-Term Deformation In The Southern Olympic Mountains Of Washington State, Jaime Delano
WWU Graduate School Collection
Understanding topographic development in subduction zone forearcs requires comparison of deformation at short and long-term time intervals. We focus here on geomorphic records of uplift and incision in the Cascadia forearc of Washington State for comparison with short-term deformation driven by subduction zone coupling. We use surficial geologic mapping, optically stimulated luminescence dating, and surveyed terrace strath elevations to document fluvial incision and fault slip rates in the Wynoochee River valley in the southern Olympic Mountains. Results from 14 optically stimulated luminescence samples yield fluvial terrace age groupings of ~7-12 ka, ~14-18 ka, ~30-45 ka, and ~50-60 ka, which likely …
Depositional Environments And Provenance Of Early Paleogene Strata In The Huerfano Basin: Implications For Uplift Of The Wet Mountains, Colorado, Usa, Dirk M. Rasmussen
Depositional Environments And Provenance Of Early Paleogene Strata In The Huerfano Basin: Implications For Uplift Of The Wet Mountains, Colorado, Usa, Dirk M. Rasmussen
WWU Graduate School Collection
Sedimentary basins throughout the Western Interior of North America preserve a record of Late Cretaceous through latest Eocene sedimentation derived from flanking Laramide uplifts. In northern and western basins, the strata contain a well-documented proxy history of Laramide-style exhumation and climatic conditions within the region. However, the tectonic and climatic histories of more southerly basins, such as the Huerfano Basin studied herein, are comparatively underdeveloped despite being key in understanding the spatiotemporal evolution of Laramide tectonism and regional climatic gradients. This study addresses this issue and presents the first detailed lithofacies analysis and provenance analysis of the Poison Canyon, Cuchara, …
Emergent Wetland Plant Biophysical Characteristics Associated With Wave Attenuation And Sediment Retention, Chad D. Stellern
Emergent Wetland Plant Biophysical Characteristics Associated With Wave Attenuation And Sediment Retention, Chad D. Stellern
WWU Graduate School Collection
Estuarine wetlands have proven a cost-effective buffer against coastal hazards because they reduce erosive wave energy and enable sediment retention by producing hydraulic friction. Human modifications to coastal hydrology and sediment transport have resulted in loss of wetlands and associated protection. Our study area, the Stillaguamish Delta has experienced a 55% loss in wetlands and significant marsh retreat (Grossman and Curran (in review)). We quantified vegetation characteristics (spatial, vertical and, seasonal) that effect wave attenuation using image analysis, remote sensing and, in-situ measurements. We produced a sediment budget for the northern region and evaluate suspended sediment dynamics. Our elasticity and …
Modeling The Effects Of Forecasted Climate Change And Glacier Recession On Late Summer Streamflow In The Upper Nooksack River Basin, Ryan D. Murphy
Modeling The Effects Of Forecasted Climate Change And Glacier Recession On Late Summer Streamflow In The Upper Nooksack River Basin, Ryan D. Murphy
WWU Graduate School Collection
Like many watersheds in the North Cascades range of Washington State, USA, streamflow in the Nooksack River is strongly influenced by precipitation and snowmelt in the spring and glacial ice melt in the warmer summer months. With a maritime climate and high relief containing approximately 34km2 of glacial ice, the streamflow response in the Nooksack River basin is sensitive to increases in temperature. Climate projections from global climate models (GCMs) for the 21st Century indicate increases in temperature with variable changes to precipitation. The watershed is a valuable freshwater resource for regional municipalities, industry, and agriculture, and provides critical …
Mineral Complexities As Evidence For Open-System Processes In Formation Of Intermediate Magmas Of The Mount Baker Volcanic Field, Northern Cascade Arc, Ricardo D. (Ricardo Daniel) Escobar-Burciaga
Mineral Complexities As Evidence For Open-System Processes In Formation Of Intermediate Magmas Of The Mount Baker Volcanic Field, Northern Cascade Arc, Ricardo D. (Ricardo Daniel) Escobar-Burciaga
WWU Graduate School Collection
To better understand the complex history of open system differentiation in intermediate subduction zone magmas, complex crystal populations from andesites in the Mount Baker volcanic field (MBVF) in the northern Cascade arc were analyzed. Previous studies have suggested that open-system processes play a dominant role in the petrogenesis of these andesites; however, the studies relied heavily on bulk rock compositions and overlooked complex mineral textures and compositions. This study focuses on establishing mineral and crystal clot populations in four andesite flow units, from which co-crystallizing assemblages were identified. The flow units are the medium-K andesites of Swift Creek (asw …