Earth Sciences Commons^™

Connectivity: Insights From The U.S. Long Term Ecological Research Network, David M. Iwaniec, Michael Gooseff, Katharine N. Suding, David Samuel Johnson, Daniel C. Reed, Debra P. C. Peters, Byron Adams, John E. Barrett, Brandon T. Bestelmeyer, Max C. N. Castorani, Elizabeth M. Cook, Melissa J. Davidson, Peter M. Groffman, Niall P. Hanan, Laura F. Huenneke, Pieter T. J. Johnson, Diane M. Mcknight, Robert J. Miller, Gregory S. Okin, Daniel L. Preston, Andrew Rassweiler, Chris Ray, Osvaldo E. Sala, Robert L. Schooley, Timothy Seastedt, Marko J. Spasojevic, Enrique R. Vivoni

Advanced Science Research Center

Ecosystems across the United States are changing in complex and surprising ways. Ongoing demand for critical ecosystem services requires an understanding of the populations and communities in these ecosystems in the future. This paper represents a synthesis effort of the U.S. National Science Foundation-funded Long-Term Ecological Research (LTER) network addressing the core research area of “populations and communities.” The objective of this effort was to show the importance of long-term data collection and experiments for addressing the hardest questions in scientific ecology that have significant implications for environmental policy and management. Each LTER site developed at least one compelling case …

Cascading Effects: Insights From The U.S. Long Term Ecological Research Network, Christie A. Bahlai, Clarisse Hart, Maria T. Kavanaugh, Jeffrey D. White, Roger W. Ruess, Todd J. Brinkman, Hugh W. Ducklow, David R. Foster, William R. Fraser, Hélène Genet, Peter M. Groffman, Stephen K. Hamilton, Jill F. Johnstone, Knut Kielland, Douglas A. Landis, Michelle C. Mack, Orlando Sarnelle, Jonathan R. Thompson

Advanced Science Research Center

Ecosystems across the United States are changing in complex and unpredictable ways and analysis of these changes requires coordinated, long-term research. This paper is a product of a synthesis effort of the U.S. National Science Foundation funded Long-Term Ecological Research (LTER) network addressing the LTER core research area of “populations and communities.” This analysis revealed that each LTER site had at least one compelling “story” about what their site would look like in 50–100 yr. As the stories were prepared, themes emerged, and the stories were group into papers along five themes: state change, connectivity, resilience, time lags, and cascading …

Trondhjemite Leucosomes Generated By Partial Melting Of A Hornblende-Gabbro (Alvand Plutonic Complex, Hamedan, Nw Iran), Adel Saki, Federico Lucci, Mirmohammad Miri, John C. White

EKU Faculty and Staff Scholarship

This work describes the petrogenesis of in situ and in-source trondhjemite leucosomes generated by low-degree partial melting of the Jurassic Cheshmeh-Ghasaban hornblende-gabbros in the northern Alvand batholith (Hamedan, NW Iran). These leucosomes occur in a metatexite migmatite as patches, net-structures, veinlets, and dikes at scales ranging from a few millimetres to a few metres. They have high SiO2 (mean ≈ 78 wt%) and Na2O (4–5 wt%) with low Al2O3 (wt%), K2 O (

Analysis Of Vibracores From The New Hampshire Continental Shelf From 1984 And 1988, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Center for Coastal and Ocean Mapping

During this study, the twenty-three vibracores taken in 1984 and 1988 were reexamined, original descriptions verified and significantly expanded, and the cores sampled to provide complete grain size data (i.e. the original sediment grain size analyses were limited). The vibracores were grouped by location with respect to major physiographic features (geoforms) or surficial sediment type including Offshore Marine-Modified Glacial Features (Drumlins and Lodgement Till Deposits), Northern Sand Body, Isles of Shoals, Nearshore Marine-Modified Glacial Features (Eskers and Drumlins), Nearshore Sheet Sand, and Offshore Seafloor Plain.

The Northern Sand Body (NSB), located near the Isles of Shoals ~10 km from shore, …

New Hampshire Atlantic Beaches: 2017 Field Campaign Database - Field And Sample Photographs And Sediment Data, Larry Ward, Nathan W. Corcoran, Zachary S. Mcavoy, Rachel C. Morrison

Center for Coastal and Ocean Mapping

Sediment data, sediment photographs, and field photographs from a major field campaign conducted on the New Hampshire Atlantic beaches in 2017 are presented here. Research was carried out with the purpose of better understanding how sediment grain size of NH beaches varies under accretional and erosional conditions. Seven major beaches along the NH coast (Wallis Sands, Foss Beach, Jenness Beach, North Hampton Beach, North Beach, Hampton Beach, and Seabrook Beach) representing the range of morphologic and sedimentologic types found on the NH coast were sampled along multiple transects and multiple locations on each transect. This work provides baseline data to …

New Hampshire And Vicinity Continental Shelf: Sand And Gravel Resources, Larry G. Ward, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Center for Coastal and Ocean Mapping

The continental shelf off New Hampshire (NH) has extensive marine-modified glacial deposits and associated shoals. These features are potential targets for sand and gravel resources for beach nourishment and other efforts to build coastal resiliency. The distribution of sand and gravel deposits was evaluated based on the synthesis of relatively recent high-resolution bathymetry, new surficial sediment and geoform maps, and an extensive data archive that includes over ~1280 km of seismic profiles, ~750 grain size analyses, and 23 vibracores. This work heavily utilizes the results of previous research on mineral resources on the NH shelf by Birch (1984) …

Surficial Geology Of The Continental Shelf Off New Hampshire: Morphologic Features And Surficial Sediment, Larry G. Ward, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani, Rachel C. Morrison

Center for Coastal and Ocean Mapping

The continental shelf off New Hampshire (NH) in the Western Gulf of Maine (WGOM) is extremely complex and includes extensive bedrock outcrops, marine-modified glacial deposits, marine-formed shoals, seafloor plains, and associated features that are composed of a range of sediment types from mud to gravel. Furthermore, the physiography and composition of the seafloor frequently changes dramatically over relatively short distances (tens of meters). The complexity of the WGOM seafloor results from the interplay of glaciations, sea-level fluctuations, and marine processes (waves and currents). High-resolution multibeam echosounder (MBES) bathymetry and backscatter surveys, along with ground truth consisting of archived seismic reflection …

Seasonal Changes In Sediment Grain Size Of New Hampshire Atlantic Beaches, Larry G. Ward, Nathan W. Corcoran, Zachary S. Mcavoy, Rachel C. Morrison

Center for Coastal and Ocean Mapping

The beaches along the New Hampshire Atlantic coast are essential to the local and regional economy and are one of the major attractions of the seacoast. Beyond their economic importance, the beaches also have great aesthetic and ecological value that are vital to the character and history of New Hampshire. Unfortunately, climate change and an acceleration in sea-level rise, coupled with a major reduction in sediment supply and extensive development (including engineering structures along the coast), has led to loss of elevation and narrowing of many of the beaches. The forecast is that these trends will continue and likely become …

Erosion And Accretion Trends Of New Hampshire Beaches From December 2016 To March 2020: Results Of The Volunteer Beach Profile Monitoring Program, Larry G. Ward, Rachel C. Morrison, Alyson L. Eberhardt, Wellsley J. Costello, Zachary S. Mcavoy, Caitlin P. Mandeville

Center for Coastal and Ocean Mapping

New Hampshire Atlantic beaches were monitored from December 2016 to March 2020 to determine seasonal changes in morphology and elevation, assess the response of the beaches to storms with respect to erosion and subsequent recovery, and develop a baseline to determine long-term trends in beach size, elevation, and position. A unique aspect of this study was the involvement of community volunteers working together with the University of New Hampshire (UNH) Center for Coastal and Ocean Mapping, UNH Cooperative Extension, New Hampshire Sea Grant, and the New Hampshire Geological Survey. The monitoring network consisted of thirteen stations located at six of …

Climate Change Impacts Go Beyond The Surface: Groundwater Recharge Rates And Aquifer Resources Across The Contiguous United States, Kendra R. Devereux

Senior Independent Study Theses

Groundwater is a primary source of potable water for millions and a major source for crop irrigation in the United States. Thus, it is vital to understand current and future rates of recharge to predict and manage groundwater availability. In this study, current groundwater recharge rates across the Contiguous US at 800m resolution are estimated by following methods presented by Reitz et al. (2017), and the reproducibility of the methods are assessed. A water budget approach is implemented where quick flow runoff and evapotranspiration rates are subtracted from precipitation rates. Precipitation was found to be the most reproducible water budget …

The Development Of A Procedure For The Pxrf Analysis Of Soil Cation Exchange Capacity In Collaboration With Colorado Farmers, Claire E. Wineman

Senior Independent Study Theses

Discrepancies between farmers’ and scientists’ knowledge systems and experiences have long prevented the success and mutual beneficiality of collaborative research efforts between these two groups. The development of agricultural technologies, such as portable X-ray fluorescence (PXRF) for the analysis of soil cation exchange capacity in the field, creates a promising overlap point for farmers and scientists to cooperatively study issues within their sociocultural context and with access to institutional resources. In this study, the generation of an in-field PXRF method in collaboration with Colorado farmers helps to provide a prospective model for scientists and farmers looking to use collaborative research …

Investigation Of Statistical Seismology In Thailand-Laos-Myanmar Borders, Manunchaya Neanudorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this research is to understand more about the statistical seismology of the Thailand-Laos-Myanmar border in order to monitor earthquake activity and locate potentially dangerous area. The seismicity data was collected from the Thailand Meteorological Department. Following that, the catalog's homogeneity and completeness were improved. The first step is to identify the earthquake activity by using the adaptive frequency-magnitude distribution. The results are that Nan province, Thailand, and south Luang Prabang, Laos are the highest activity areas which can generate a maximum magnitude of 5.1 ML, 5.6 ML, 6.3 ML, and 6.7 ML in 5, 10, 30, 50 …

Analysis Of Ancient Storm Deposits Along Coastal Areas Of Andaman Sea, Thailand And Coastal Areas Of South China Sea, Vietnam, Stapana Kongsen

Chulalongkorn University Theses and Dissertations (Chula ETD)

The frequency of high energy storm and tsunami events is crucial for apprehending the vulnerability of coastal communities. Identifying and dating sedimentary evidence deposited by such high energy events can assist in the planning and installation of suitable protection measurements. The Andaman Sea coast of Thailand is particularly vulnerable to such events as illustrated by the 2004 Indian Ocean Tsunami (2004 IOT) and the South China Sea coast of Vietnam has been experienced from the past severe storm event. Here, the authors study the high energy sediments. The selected area of Andaman Sea coast Thailand is Laem Son National park, …

Trace Elements And Color-Causing Role In Spinel And Tanzanite, Teerarat Pluthametwisute

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research is aimed to investigate the significant trace elements and their color-causing roles in tanzanite and spinels (7 color varieties) by focusing on their concentrations, valencies, and site occupancy since no palpable research has been reported previously either before or after heating of both gems. According to this finding, natural tanzanites usually show strongly trichroic colors of violet, blue, and brown in different directions. However, this characteristic is easily changed to violet-blue dichroism after heat treatment. As the result, the violet-blue absorption band (centered around 450–460 nm) is obviously decreased after heating, and XAS analysis indicates the higher valency …

Stratigraphy And Paleoenvironment Of Thong Pha Phum Group In Kanchanaburi Province, Warunee Maneerat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purposes of this study are to establish the detail lithology, stratigraphy, lithofacies and systematic paleontology of marine Silurian-Devonian sedimentary rocks of the Thong Pha Phum Group in Ban Tha Kraden, Si Sawat District, Kanchanaburi Province, and to interpret and reconstruct its depositional environment. The Thong Pha Phum Group is well exposed in the study area. It consists mainly of shale, siltstone, sandstone, limestone, argillaceous limestone, calcareous shale, calcareous mudstone, and laminated mudstone with the many fossils such as graptolites, tentaculites, ostracods, brachiopods, nautiloids and trilobites. These strata are conformably underlain by the Thung Song Group (Ordovician age) and are …

A Development Of Disaster Risk Profile In Public Healthcare System During Flood Situation : A Case Study Of Nakhon Sawan City Municipality, Nakhon Sawan Province, Thailand, Kodchakorn Krutphong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research begins with the idea of the disaster risk assessment included in the disaster management’s well recognized international framework, the Sendai Framework for Disaster Risk Reduction. Then, the idea settles from the risk assessment concept combined with the emergency management knowledge that has the critical infrastructure topic, including the public healthcare system. The flood disaster is the kind of disaster that frequently occurs in Thailand and the study area, Nakhon Sawan City Municipality. Thus, this research aims to study disaster risk profiles in the public healthcare system in a specific local area. The outcome from this research is the …

การวิเคราะห์เชิงสถาบันของระบบเตือนภัยล่วงหน้าสำหรับอุทกภัยในประเทศไทย กรณีศึกษา อุทกภัยจากอิทธิพลพายุโซนร้อนปาบึก พ.ศ.2562 ในจังหวัดนครศรีธรรมราช, ธวัฒชัย ปาละคะมาน

Chulalongkorn University Theses and Dissertations (Chula ETD)

การวิจัยในครั้งนี้มีวัตถุประสงค์เพื่อ 1) ทบทวนบริบทและแนวคิดระบบเตือนภัยล่วงหน้าสำหรับอุทกภัยที่มีในประเทศไทยและต่างประเทศ 2) ศึกษาการบริหารจัดการของระบบเตือนภัยล่วงหน้าสำหรับอุทกภัยของประเทศไทยในเหตุการณ์อุทกภัยจากอิทธิพลพายุโซนร้อนปาบึกในพื้นที่จังหวัดนครศรีธรรมราช 3) ข้อเสนอแนะเชิงนโยบายต่อการเสริมสมรรถนะกลไกเชิงสถาบันของระบบเตือนภัยล่วงหน้าสำหรับอุทกภัยของประเทศไทยในพื้นที่จังหวัดนครศรีธรรมราช โดยใช้วิธีการวิจัยแบบผสมผสาน ซึ่งมีการใช้เครื่องมือการวิเคราะห์เครือข่ายทางสังคมและการสัมภาษณ์เชิงลึก วิธีเชิงปริมาณโดยใช้แบบสอบถาม ผลจากการวิเคราะห์ข้อมูล พบว่า 1) ประเทศไทยมีหน่วยงานที่มีอำนาจหน้าที่ตามกฎหมายเพื่อดำเนินการด้านการเตือนภัยจำนวนมาก แต่มีการดำเนินการเตือนภัยที่สอดคล้องกับมาตรฐานสากลโดยเฉพาะในหน่วยงานระดับส่วนกลาง 2) ภาพรวมของเครือข่ายการเตือนภัยล่วงหน้าอยู่ในลักษณะการผสมผสานระหว่างเครือข่ายตารางแบบบางส่วนกับเครือข่ายที่เข้าถึงได้หลายช่องทางที่ไม่สมบูรณ์ บ่งชี้ 2.1) เครือข่ายขาดการกำหนดบทบาทหน้าที่และทิศทางอย่างเป็นทางการจึงให้สมาชิกในเครือข่ายมีปฏิสัมพันธ์กันต่ำ 2.2) สมาชิกในเครือข่ายไม่มีการดำเนินกิจกรรมด้านการเตือนภัยล่วงหน้าเป็นการเฉพาะที่ก่อให้เกิดการปฏิสัมพันธ์ระหว่างกัน ส่งผลให้เครือข่ายขาดความเหนียวแน่น และ 2.3) เครือข่ายในระดับท้องถิ่นขาดการเชื่อมโยงกับกลไกการเตือนภัยล่วงหน้าอย่างเป็นระบบ 3) เสนอให้มีการกำหนดให้มียุทธศาสตร์การเตือนภัยล่วงหน้าเป็นการเฉพาะที่กำหนดความสัมพันธ์เชิงอำนาจอย่างเป็นทางการของหน่วยงานต่าง ๆ ให้สอดคล้องกันตลอดจนกำหนดกลไกการติดตาม การประเมินผล และการพิจารณางบประมาณด้านการเตือนภัยที่มีเอกภาพทั้งประเทศ ตลอดจนกำหนดกลไกแลการเตรียมพร้อมด้านการเตือนภัยในระดับพื้นที่อย่างเป็นรูปธรรมในแผนการจัดการภัยพิบัติท้องถิ่น และจัดให้มือคู่มือมาตรฐานปฏิบัติการด้านการเตือนภัย

การวิเคราะห์การหน่วงน้ำเพื่อบรรเทาภาวะน้ำท่วมในเขตเมือง กรุงเทพมหานครด้วยการตัดสินใจแบบหลายเกณฑ์, สุพัชร เทพรส

Chulalongkorn University Theses and Dissertations (Chula ETD)

ประเทศไทยได้รับผลกระทบจากการเปลี่ยนแปลงสภาพภูมิอากาศมากขึ้นและรุนแรงขึ้นทำให้เกิดความถี่ของฝนตกหนักมากเพิ่มขึ้น กอปรกับการเปลี่ยนแปลงประเภทการใช้ที่ดินที่มีผลต่อค่าสัมประสิทธิ์การซึมผ่านได้ของดิน การศึกษาวิจัยนี้จึงได้นำแนวคิดของหน้าที่ต้นไม้ในเมืองในระดับยอด ระดับลำต้น ระดับพื้นดินและระดับใต้ดิน เข้ามาประยุกต์ใช้กับโครงสร้างหน่วงน้ำในเมืองที่มีความสัมพันธ์กับปัจจัยพื้นที่ในกรุงเทพมหานคร เพื่อช่วยบรรเทาสภาวะน้ำท่วมจากฝนตกหนัก ข้อมูลเก็บจากแบบสอบถามจากผู้เชี่ยวชาญ 13 คน แล้วใช้เทคนิค Pairwise Comparison เพื่อหาค่าน้ำหนักความสำคัญของปัจจัยพื้นที่ที่มีผลต่อการหน่วงน้ำ และใช้ Decision Matrix และเกณฑ์ค่าควอร์ไทล์ที่ 3 (Q3) เพื่อหาการประยุกต์ใช้โครงสร้างหน่วงน้ำบนปัจจัยพื้นที่ต่างๆ ผลการศึกษาพบว่า ผู้เชี่ยวชาญให้ค่าน้ำหนักความสำคัญมากที่สุดกับการระบายน้ำของที่ดิน(33%) รองลงมาคือการใช้ประโยชน์ของที่ดิน(22%) ระดับความสูงของที่ดิน(19%) การซึมน้ำของที่ดิน(16%) และกรรมสิทธิ์ของที่ดิน(10%) ตามลำดับ ที่ดินของภาครัฐมีความเป็นไปได้ที่จะประยุกต์ใช้โครงสร้างหน่วงน้ำมากกว่าที่ดินของเอกชน พื้นที่บริเวณทางเท้าเหมาะสมที่จะใช้พื้นน้ำซึมได้ โครงการจัดการน้ำไหลนองควรส่งเสริมใช้กับคูคลองและถนน ความเข้าใจในหน้าที่ของโครงสร้างสีเขียวเป็นประเด็นเร่งด่วนที่ควรส่งเสริมเข้าไปในชุมชนของกรุงเทพมหานคร โครงสร้างสีเขียวเป็นทั้งตัวกรองดูดซับมลพิษทางอากาศ ดิน และน้ำสำหรับชุมชน อีกทั้งยังช่วยป้องกันน้ำท่วมในขณะที่เกิดฝนตกหนักและสร้างระบบนิเวศที่หลากหลายสอดคล้องตามโครงการกรุงเทพสีเขียว 2030

The Radius Of The Umbrella Cloud Helps Characterize Large Explosive Volcanic Eruptions, Robert Constantinescu, Aurelian Hopulele-Gligor, Charles Connor, Costanza Bonadonna, Laura Connor, Jan Lindsay, Sylvain Charbonnier, Alain C.M. Volentik

School of Geosciences Faculty and Staff Publications

Eruption source parameters (in particular erupted volume and column height) are used by volcanologists to inform volcanic hazard assessments and to classify explosive volcanic eruptions. Estimations of source parameters are associated with large uncertainties due to various factors, including complex tephra sedimentation patterns from gravitationally spreading umbrella clouds. We modify an advection-diffusion model to investigate this effect. Using this model, source parameters for the climactic phase of the 2450 BP eruption of Pululagua, Ecuador, are different with respect to previous estimates (erupted mass: 1.5–5 × 10¹¹ kg, umbrella cloud radius: 10–14 km, plume height: 20–30 km). We suggest large …

Magmatic Response To Subduction Initiation, Part Ii: Boninites And Related Rocks Of The Izu‐Bonin Arc From Iopd Expedition 352, John W. Shervais, Mark K. Reagan, Marguerite Godard, Julie Prytulak, Jeffrey G. Ryan

School of Geosciences Faculty and Staff Publications

International Ocean Discovery Program Expedition 352 to the Izu‐Bonin forearc cored over 800 m of basement comprising boninite and boninite‐series lavas. This is the most extensive, well‐constrained suite of boninite series lavas ever obtained from in situ oceanic crust. The boninites are characterized as high‐silica boninite (HSB), low‐silica boninite (LSB), or basaltic boninite based on their SiO₂‐MgO‐TiO₂ relations. The principal fractionation products of all three series are high‐Mg andesites (HMA). Lavas recovered >250 meters below seafloor (mbsf) erupted at a forearc spreading axis and are dominated by LSB and HMA. Lavas recovered fromoff‐axis and are dominated by …

Linking Landscape Attributes To Salmon And Decision-Making In The Southern Kenai Lowlands, Alaska, Usa, Coowe M. Walker, Dennis F. Whigham, I. Syverine Bentz, Jacob M. Argueta, Ryan S. King, Mark C. Rains, Charles A. Simenstad, Chris Guo, Steven J. Baird, Conrad J. Field

School of Geosciences Faculty and Staff Publications

While Pacific salmon are economically and culturally important worldwide, Alaska, USA is one of the few remaining places on earth where sustainable management of salmon is possible, even in the face of wide-ranging threats, including overharvesting and the impacts of climate change. A continuing challenge that we face is to understand the ecological processes that result in sustainable salmon populations and report that science to stakeholders in a way that promotes decision-making to avoid the destruction of salmon populations that has occurred in most areas of the lower 48 states. To address this challenge, our studies in the southern Kenai …

Ethical Product Havens In The Global Diamond Trade: Using The Wayback Machine To Evaluate Ethical Market Outcomes, Trina Hamilton, Seth Cavello

School of Geosciences Faculty and Staff Publications

Who benefits from ethical product markets? While most ethical products (e.g. fair trade and eco-certified products) are intended to benefit marginalized communities and vulnerable ecosystems, the reality is that the geographic preferences exhibited by so-called ethical markets may, in fact, reinforce global inequities rather than remedy them. It can be difficult to evaluate the outcomes of ethical product markets, however, because we are often limited to data from a small number of industries with widely used standards and certifications. This research pilots a new methodology, using an online archive—the Wayback Machine, to evaluate shifts in countries' ethical market share, focusing …

Impulsive Volcanic Plumes Generate Volcanic Lightning And Vent Discharges: A Statistical Analysis Of Sakurajima Volcano In 2015, Cassandra M. Smith, Damien Gaudin, Alexa R. Van Eaton, Sonja A. Behnke, Steven Reader, Ronald J. Thomas, Harald Edens, Stephen R. Mcnutt, Corrado Cimarelli

School of Geosciences Faculty and Staff Publications

The origin of electrical activity accompanying volcanic ash plumes is an area of heightened interest in volcanology. However, it is unclear how intense an eruption needs to be to produce lightning flashes as opposed to “vent discharges,” which represent the smallest scale of electrical activity. This study targets 97 carefully monitored plumesJapan, from June 1 to 7, 2015. We use multiparametric measurements from sensors including a nine-station lightning mapping array and an infrared camera to characterize plume ascent. Findings demonstrate that the impulsive, high velocity plumes (>55 m/s) were most likely to create vent discharges, whereas lightning flashes occurred …

Molybdenum Isotopes Unmask Slab Dehydration And Melting Beneath The Mariana Arc, Hong-Yan Li, Rui-Peng Zhao, Jie Li, Yoshihiko Tamura, Christopher Spencer, Robert J. Stern, Jeffrey G. Ryan, Yi-Gang Xu

School of Geosciences Faculty and Staff Publications

How serpentinites in the forearc mantle and subducted lithosphere become involved in enriching the subarc mantle source of arc magmas is controversial. Here we report molybdenum isotopes for primitive submarine lavas and serpentinites from active volcanoes and serpentinite mud volcanoes in the Mariana arc. These data, in combination with radiogenic isotopes and elemental ratios, allow development of a model whereby shallow, partially serpentinized and subducted forearc mantle transfers fluid and melt from the subducted slab into the subarc mantle. These entrained forearc mantle fragments are further metasomatized by slab fluids/melts derived from the dehydration of serpentinites in the subducted lithospheric …

Large-Volume And Shallow Magma Intrusions In The Blackfoot Reservoir Volcanic Field (Idaho, Usa), M. S. Hastings, C. B. Connor, P. Wetmore, R. Malservisi, L. J. Connor, M. Rodgers, P. C. Femina

School of Geosciences Faculty and Staff Publications

he Blackfoot Reservoir volcanic field (BRVF), Idaho, USA, is a bimodal volcanic field that has hosted silicic eruptions during at least two episodes, as recently as 58 ka. Using newly collected ground and boat-based gravity data, two large negative anomalies (-16 mGal) are modeled as shallow (< 1  km) intrusions beneath a NE-trending alignment of BRVF rhyolite domes and tuff rings. Given the trade-off between density contrast and model volume, best-fit gravity inversion models yield a total intrusion volume of 50-120 km³; a density contrast of -400 kg m^-3 results in two intrusions, each ~9 km x 4.5 km and about 0.5 km thick, with cumulative volume of 100 km³. A network of 340°-360° trending faults lies directly above and on the margins of the mapped gravity anomalies. Most of …

Independent, Semi-Automated Classification Of Petrographic Features In Volcanic Rocks Using Fiji And Weka, Holly Danielle Pettus

Graduate Theses, Dissertations, and Problem Reports (ETD)

Traditional methods of collecting quantitative petrographic data from thin sections (modal mineralogy, size distribution, shapes, etc.) are time- and labor-intensive, and rarely have sample sizes adequate to statistically describe complex rocks (i.e. volcanic rocks). Although manual counting and measurements are now routinely supplemented by digital image analysis, the majority of quantitative petrographic studies still go through a manual digitization stage where object classes are traced before further analyses. This is a major rate-limiting step that reproduces the same problems of small n-values resulting from significant effort. We have valuated the potential and limitations of using the Trainable Weka Segmentation (TWS) …

Wave Climate Associated With Changing Water Level And Ice Cover In Lake Michigan, Chenfu Huang, Longhuan Zhu, Gangfeng Ma, Guy A. Meadows, Pengfei Xue

Civil & Environmental Engineering Faculty Publications

Detailed knowledge of wave climate change is essential for understanding coastal geomorphological processes, ecosystem resilience, the design of offshore and coastal engineering structures and aquaculture systems. In Lake Michigan, the in-situ wave observations suitable for long-term analysis are limited to two offshore MetOcean buoys. Since this distribution is inadequate to fully represent spatial patterns of wave climate across the lake, a series of high-resolution SWAN model simulations were performed for the analysis of long-term wave climate change for the entirety of Lake Michigan from 1979 to 2020. Model results were validated against observations from two offshore buoys and 16 coastal …

Characterizing Seagrass Effects On Hydrodynamics Of Waves And Currents Through Field Measurements And Computational Modelling, Ramin Familkhalili, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Low-lying coastal and estuarine areas are among the most populated regions globally, have high economic significance, and are increasingly threatened by climate change, sea level rise, nuisance flooding, and extreme storms. Nature-based coastal protections are sustainable and sea-level resilient alternatives compared to traditional solutions such as dikes and seawalls. Submerged aquatic vegetation (SAV) or seagrasses can provide coastal flood and erosion protection by attenuating storm wave and current energy and stabilizing seabed sediments. However, more research is needed to understand the interactions between flow, SAVs, and sediments. These dynamic interactions affect flow at different scales and seagrass productivity. In this …

Effects Of Hydrological And Climatic Variables On Cyanobacterial Blooms In Four Large Shallow Lakes Fed By The Yangtze River, Jian Huang, Qiujin Xu, Xixi Wang, Hao Ji, Edward J. Quigley, Mohamadali Sharbatmaleki, Simeng Li, Beidou Xi, Biao Sun, Caole Li

Civil & Environmental Engineering Faculty Publications

Shallow lakes, one of the most widespread water bodies in the world, are easily shifted to a new trophic state due to external interferences. Shifting hydrologic conditions and climate change can cause cyanobacterial harmful algal blooms (CyanoHABs) in shallow lakes, which pose serious threats to ecological integrity and human health. This study analyzed the effects of hydrologic and meteorological variables on cyanobacterial blooms in Yangtze-connected lakes (Lake Dongting and Poyang) and isolated lakes (Lake Chao and Tai). The results show that (i) chlorophyll-a (Chl-a) concentration tends to decrease exponentially with increasing relative lake level fluctuations (RLLF) and precipitation, but to …

Seasonal Dispersal Of Fjord Meltwaters As An Important Source Of Iron And Manganese To Coastal Antarctic Phytoplankton, Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, Katherine A. Barbeau

OES Faculty Publications

Glacial meltwater from the western Antarctic Ice Sheet is hypothesized to be an important source of cryospheric iron, fertilizing the Southern Ocean, yet its trace-metal composition and factors that control its dispersal remain poorly constrained. Here we characterize meltwater iron sources in a heavily glaciated western Antarctic Peninsula (WAP) fjord. Using dissolved and particulate ratios of manganese to iron in meltwaters, porewaters, and seawater, we show that surface glacial melt and subglacial plumes contribute to the seasonal cycle of iron and manganese within a fjord still relatively unaffected by climate-change-induced glacial retreat. Organic ligands derived from the phytoplankton bloom and …