Thermomechanical Modeling of the Formation of a Multilevel, Crustal-scale Magmatic System by the Yellowstone Plume

Thermomechanical Modeling of the Formation of a Multilevel, Crustal-scale Magmatic System by the Yellowstone Plume PDF Author: Dylan P. Colon
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages : 18

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Book Description
Geophysical imaging of the Yellowstone supervolcano shows a broad zone of partial melt interrupted by an amagmatic gap at depths of 15-20 km. We reproduce this structure through a series of regional-scale magmatic-thermomechanical forward models which assume that magmatic dikes stall at rheologic discontinuities in the crust. We find that basaltic magmas accumulate at the Moho and at the brittle-ductile transition, which naturally forms at depths of 5-10 km. This leads to the development of a 10-15 km thick mid-crustal sill complex with a top at a depth of approximately 10 km, consistent with geophysical observations of the pre-Yellowstone hotspot track. We show a linear relationship between melting rates in the mantle and rhyolite eruption rates along the hotspot track. Finally, melt production rates from our models suggest that the Yellowstone plume is ~175°C hotter than the surrounding mantle and that the thickness of the overlying lithosphere is ~80 km.

Thermomechanical Modeling of the Formation of a Multilevel, Crustal-scale Magmatic System by the Yellowstone Plume

Thermomechanical Modeling of the Formation of a Multilevel, Crustal-scale Magmatic System by the Yellowstone Plume PDF Author: Dylan P. Colon
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages : 18

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Book Description
Geophysical imaging of the Yellowstone supervolcano shows a broad zone of partial melt interrupted by an amagmatic gap at depths of 15-20 km. We reproduce this structure through a series of regional-scale magmatic-thermomechanical forward models which assume that magmatic dikes stall at rheologic discontinuities in the crust. We find that basaltic magmas accumulate at the Moho and at the brittle-ductile transition, which naturally forms at depths of 5-10 km. This leads to the development of a 10-15 km thick mid-crustal sill complex with a top at a depth of approximately 10 km, consistent with geophysical observations of the pre-Yellowstone hotspot track. We show a linear relationship between melting rates in the mantle and rhyolite eruption rates along the hotspot track. Finally, melt production rates from our models suggest that the Yellowstone plume is ~175°C hotter than the surrounding mantle and that the thickness of the overlying lithosphere is ~80 km.

Volumes, Timescales, and Frequency of Magmatic Processes in the Earth’s Lithosphere – Part I and II

Volumes, Timescales, and Frequency of Magmatic Processes in the Earth’s Lithosphere – Part I and II PDF Author: Mattia Pistone
Publisher: Frontiers Media SA
ISBN: 2889637778
Category :
Languages : en
Pages : 207

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Book Description


Introduction to Numerical Geodynamic Modelling

Introduction to Numerical Geodynamic Modelling PDF Author: Taras Gerya
Publisher: Cambridge University Press
ISBN: 1107143144
Category : Mathematics
Languages : en
Pages : 487

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Book Description
The second edition of this popular introduction to numerical geodynamic modelling theory and applications features four new chapters. Based on the author's experience of teaching the material, and including practical exercises and MATLAB® examples, this user-friendly resource encourages students and researchers to experiment with geodynamic models.

Dangerous Earth

Dangerous Earth PDF Author: Ellen Prager
Publisher: University of Chicago Press
ISBN: 022654172X
Category : Science
Languages : en
Pages : 247

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Book Description
The Earth is a beautiful and wondrous planet, but also frustratingly complex and, at times, violent: much of what has made it livable can also cause catastrophe. Volcanic eruptions create land and produce fertile, nutrient-rich soil, but they can also bury forests, fields, and entire towns under ash, mud, lava, and debris. The very forces that create and recycle Earth’s crust also spawn destructive earthquakes and tsunamis. Water and wind bring and spread life, but in hurricanes they can leave devastation in their wake. And while it is the planet’s warmth that enables life to thrive, rapidly increasing temperatures are causing sea levels to rise and weather events to become more extreme. Today, we know more than ever before about the powerful forces that can cause catastrophe, but significant questions remain. Why can’t we better predict some natural disasters? What do scientists know about them already? What do they wish they knew? In Dangerous Earth, marine scientist and science communicator Ellen Prager explores the science of investigating volcanoes, earthquakes, tsunamis, hurricanes, landslides, rip currents, and—maybe the most perilous hazard of all—climate change. Each chapter considers a specific hazard, begins with a game-changing historical event (like the 1980 eruption of Mt. St. Helens or the landfall and impacts of Hurricane Harvey), and highlights what remains unknown about these dynamic phenomena. Along the way, we hear from scientists trying to read Earth’s warning signs, pass its messages along to the rest of us, and prevent catastrophic loss. A sweeping tour of some of the most awesome forces on our planet—many tragic, yet nonetheless awe-inspiring—Dangerous Earth is an illuminating journey through the undiscovered, unresolved, and in some cases unimagined mysteries that continue to frustrate and fascinate the world’s leading scientists: the “wish-we-knews” that ignite both our curiosity and global change.

The Yellowstone Magmatic System from the Mantle Plume to the Upper Crust Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai

The Yellowstone Magmatic System from the Mantle Plume to the Upper Crust Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai PDF Author: Hsin-Hua Huang
Publisher:
ISBN:
Category : Snake River Plain (Idaho and Or.)
Languages : en
Pages : 4

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Book Description
The Yellowstone supervolcano is one of the largest active continental silicic volcanic fields in the world. An understanding of its properties is key to enhancing our knowledge of volcanic mechanisms and corresponding risk. Using a joint local and teleseismic earthquake P-wave seismic inversion, we revealed a basaltic lower-crustal magma body that provides a magmatic link between the Yellowstone mantle plume and the previously imaged upper-crustal magma reservoir. This lower-crustal magma body has a volume of 46,000 cubic kilometers, ~4.5 times that of the upper-crustal magma reservoir, and contains a melt fraction of ~2%. These estimates are critical to understanding the evolution of bimodal basaltic-rhyolitic volcanism, explaining the magnitude of CO2 discharge, and constraining dynamic models of the magmatic system for volcanic hazard assessment.

Crustal Magmatic System Evolution

Crustal Magmatic System Evolution PDF Author: Matteo Masotta
Publisher: John Wiley & Sons
ISBN: 1119564468
Category : Science
Languages : en
Pages : 29

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Book Description
A comprehensive picture of the architecture of crustal magmatic systems The composition of igneous rocks – their minerals, melts, and fluids – reveals the physical and chemical conditions under which magmas form, evolve, interact, and move from the Earth’s mantle through the crust. These magma dynamics affect processes on the surface including crustal growth and eruptive behaviour of volcanoes. Crustal Magmatic System Evolution: Anatomy, Architecture, and Physico-Chemical Processes uses analytical, experimental, and numerical approaches to explore the diversity of crustal processes from magma differentiation and assimilation to eruption at the surface. Volume highlights include: Physical and chemical parameterization of crustal magmatic systems Experimental, theoretical and modelling approaches targeting crustal magmatic processes Timescales of crustal magmatic processes, including storage, recharge, and ascent through volcanic conduits The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about this book in a Q&A with the Editors.

Understanding the Origins of Yellowstone Hot Spot Magmas Through Isotope Geochemistry, High-precision Geochronology, and Magmatic-thermomechanical Computer Modeling

Understanding the Origins of Yellowstone Hot Spot Magmas Through Isotope Geochemistry, High-precision Geochronology, and Magmatic-thermomechanical Computer Modeling PDF Author: Dylan Colon
Publisher:
ISBN:
Category : Rhyolite
Languages : en
Pages : 321

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Book Description
The last several years have seen renewed interest in the origin of silicic magmas thanks to the developments of new microanalytical techniques allowing the measurement of the isotopic and trace element compositions of erupted magmas on sub-crystal length scales. Concurrently, there has been rapid improvement in the sophistication of computer modeling of igneous systems. This dissertation is an interdisciplinary study of the rhyolites of the Yellowstone hotspot track using both techniques. Chapters II-IV, which have all been published in existing journals, are a detailed study of the O and Hf isotopic compositions of zircon phenocrysts from large rhyolitic eruptions in the central Snake River Plain, and from rhyolites which erupted in Oregon, Idaho, and Nevada coeval with the Columbia River flood basalts. They show that rhyolites are derived from combinations of fractionates of mantle-derived basalts and of different crustal end-members which are identifiable by their distinct isotopic endmember compositions. In the Snake River Plain and Yellowstone, they recognize a common trend where early erupted rhyolites have a strong signature of melting of ancient Precambrian crust, whereas later erupted rhyolites more closely resemble the mantle in their radiogenic isotopes and are more likely to be depleted in oxygen isotopes. Diversity in zircon grain compositions also documents a batch mixing process in which multiple compositionally distinct magma bodies are assembled into a larger common magma body prior to eruption. In Chapters V and VI, the former of which has been published with the latter in preparation, a new series of magmatic-thermomechanical models is presented which assume that melts rising through the crust are arrested by strong rheological contrasts. The strongest such contrast occurs at the brittle-ductile transition at 5-10 km depth, leading to the formation of a 10-15 km thick mafic mid-crustal sill, which separates upper and lower-crustal zones of partial melt, corroborating previous geophysical imaging studies. In Chapter VI, the above isotopic trends are replicated in the modeling scheme, which shows that the source depth of crustal melts tends to shallow with time through a combination of crustal heating and repeated caldera collapses.

Unraveling the Physics of the Yellowstone Magmatic System Using Geodynamic Simulations

Unraveling the Physics of the Yellowstone Magmatic System Using Geodynamic Simulations PDF Author: Georg S. Reuber
Publisher:
ISBN:
Category : 3D model
Languages : en
Pages : 17

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Book Description
The Yellowstone magmatic system is one of the largest magmatic systems on Earth, and thus an ideal location to study magmatic processes. Whereas previous seismic tomography results could only image a shallow magma reservoir, a recent study using more seismometers showed that a second and massive partially molten mush reservoir exists above the Moho (Huang et al., 2015). To understand the measurable surface response of this system to visco-elasto-plastic deformation, it is thus important to take the whole system from the mantle plume up to the shallow magma reservoirs into account. Here, we employ lithospheric-scale 3D visco-elasto-plastic geodynamic models to test the influence of parameters such as the connectivity of the reservoirs and rheology of the lithosphere on the dynamics of the system. A gravity inversion is used to constrain the effective density of the magma reservoirs, and an adjoint modeling approach reveals the key model parameters affecting the surface velocity. Model results show that a combination of connected reservoirs with plastic rheology can explain the recorded slow vertical surface uplift rates of around 1.2 cm/year, as representing a long term background signal. A geodynamic inversion to fit the model to observed GPS surface velocities reveals that the magnitude of surface uplift varies strongly with the viscosity difference between the reservoirs and the crust. Even though stress directions have not been used as inversion parameters, modeled stress orientations are consistent with observations. However, phases of larger uplift velocities can also result from magma reservoir inflation which is a short term effect. We consider two approaches: (1) overpressure in the magma reservoir in the asthenosphere and (2) inflation of the uppermost reservoir prescribed by an internal kinematic boundary condition. We demonstrate that the asthenosphere inflation has a smaller effect on the surface velocities in comparison with the uppermost reservoir inflation. We show that the pure buoyant uplift of magma bodies in combination with magma reservoir inflation can explain (varying) observed uplift rates at the example of the Yellowstone volcanic system.

Chemical, Physical and Temporal Evolution of Magmatic Systems

Chemical, Physical and Temporal Evolution of Magmatic Systems PDF Author: L. Caricchi
Publisher: Geological Society of London
ISBN: 1862397325
Category : Science
Languages : en
Pages : 227

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Book Description
Our understanding of the physical and chemical processes that regulate the evolution of magmatic systems has improved tremendously since the foundations were laid down 100 years ago by Bowen. The concept of crustal magma chambers has progressively evolved from molten-rock vats to thermally, chemically and physically heterogeneous reservoirs that are kept active by the periodic injection of magma. This new model, while more complex, provides a better framework to interpret volcanic activity and decipher the information contained in intrusive and extrusive rocks. Igneous and metamorphic petrology, geochemistry, geochronology, and numerical modelling, all contributed towards this new picture of crustal magmatic systems. This book provides an overview of the wide range of approaches that can nowadays be used to understand the chemical, physical and temporal evolution of magmatic and volcanic systems.

Magmatic Systems

Magmatic Systems PDF Author: Michael P. Ryan
Publisher: Academic Press
ISBN: 0080959911
Category : Science
Languages : en
Pages : 427

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Book Description
With its integrated and cohesive coverage of the current research, Magmatic Systems skillfully explores the physical processes, mechanics, and dynamics of volcanism. The text utilizes a synthesized perspective--theoretical, experimental, and observational--to address the powerful regulatory mechanisms controlling the movement of melts and cooling, with emphasis on mantle plumes, mid-ocean ridges, and intraplate magmatism. Further coverage of subduction zone magmatism includes:Fluid mechanics of mixed magma migrationInternal structure of active systemsGrain-scale melt flowRheology of partial meltsNumerical simulation of porous media melt migrationNonlinear (chaotic and fractal) processes in magma transportIn all, Magmatic Systems will prove invaluable reading to those in search of an interdisciplinary perspective on this active topic. Key Features* Fluid mechanics of magma migration from surface region to eruption site* Internal structure of active magmatic systems* Grain-scale melt flow in mantle plumes and beneath mid-ocean ridges* Physics of magmatic systems and magma dynamics