Michael Manga, Ph.D. - US grants

9701768 Manga This proposal describes long-term educational and related research activities in the area of geological and environmental fluid mechanics. A set of undergraduate courses will be developed to replace the standard piece-meal and phenomenological teaching of the subject with an inductive approach; classes will focus on a set of hands-on active-learning laboratory experiments which emphasize the process of discovery. A set of graduate classes will also be developed which focus on interdisciplinary collaborative research projects, with an emphasis on interactive learning and communication. A set of complementary research activities will address problems in hydrology, geodynamics and volcanology. This work will involve the same combination of theoretical and experimental approaches that will be used in the classroom. Specific research problems include studying the hydrology of spring-dominated streams in the Oregon Cascades (research will be integrated into a summer field school), characterizing the dynamics and rheolgy of bubby magmas and lavas, developing pore length-scale models of multiphase flow in porous materials in order to understand macroscopic properties of such flows, and relating the chemical evolution of the Earth's mantle to dynamic processes. Despite the wide range of these research problems, they all share a common feature, namely, the application of quantitative methods in fluid mechanics to problems in the geological and environmental sciences. It is anticipated that much of the material for lab exercises and graduate classes will be provided by these research problems, and that the development of lab exercises will in tern provide inspiration for new research directions.

9805305
Manga
The absence of historically observed obsidian dome eruptions limits efforts to constrain the flow behavior of high-silica lavas. This project is an investigation of microstructural evidence of flow dynamics in Late Holocene (less than 2000 years old) obsidian flows in California and the Pacific Northwest. Drill cores obtained from the Inyo Domes Research Drilling Project in California preserve a nearly pristine record of microscopic textural and structural evolution of the dike, vent, and subaerial regions of the Obsidian Dome system. An innovative technique to measure the three-dimensional orientations of microlites (small crystals) will be employed. These measurements, combined with theoretical models, provide a framework for determining the relative timing of degassing, crystallization, and flow advance. Three-dimensional orientations can be used to infer conditions of flow, for example, the type of flow (pure versus simple shear), the amount of strain, and the strain-rate. For example, preliminary measurements of microlite orientations from Little Glass Mountain agree well with theoretically predicted orientation distributions of rods in simple shear flows. This project will yield information that will assist in assessing volcanic hazards associated with obsidian dome eruptions.

0112113
Ingram

This NSF grant provides partial support for the purchase of a gas source isotope ratio mass spectrometer with peripheral sample preparation attachments, to be housed in the Department of Earth and Planetary Sciences at the University of California, Berkeley. The equipment includes an automated water and carbonate preparation system and an elemental analyzer. The instrumentation will be primarily used by the research groups of the three Principal Investigators B. Lynn Ingram, Michael Manga, and Kurt Cuffey. The Department of Earth and Planetary Science has recently provided newly upgraded space to house the requested equipment. The requested package will greatly enhance the research capabilities of students, postdoctoral fellows, and faculty in the Departments of Earth and Planetary Science and Geography, and on the U.C. Berkeley campus in general. Research areas include the use of carbon, oxygen, and hydrogen isotopes in paleoclimatological and paleoenvironmental reconstructions using estuarine, wetland, lacustrine, and coastal marine sediments and corals (Dr. Ingram, Earth and Planetary Science Department), the use of oxygen and hydrogen isotopes as tracers in hydrogeologic systems (Dr. Manga, Department of Earth and Planetary Science), and the use of oxygen and deuterium isotopic ratios of water and ice in glaciologic research (Dr. Cuffey, Department of Geography). Other users of the proposed mass spectrometer facility from the Department of Earth and Planetary Science include James Kirchner (watershed hydrology and biogeochemistry, and surface process geomorphology), Walter Alvarez (asteroid impacts, tectonics of the Mediterranean region, stratigraphy of pelagic limestones), Dr. George Brimhall (mineral resources, low temperature geochemistry, soil geochemistry), and Dr. William Berry (global climate change and paleogeographic, oceanographic and life changes in the Paleozoic). Another potential user from the Department of Geography is Roger Byrne (historical biogeography, paleoenvironments of California and Mexico, and pollen analysis).
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Manga
EAR-0003303

Most erupting lavas have carried bubbles at some point during their ascent and emplacement. The effect of these bubbles on the rheological properties of magma will in turn affect the rate and style of eruption. The goal of the proposed work is thus to determine the effects of bubbles on the rheological properties of magmas and lavas for the ranges of physical parameters that are appropriate for magmatic systems. We will use three different research approaches, namely, numerical calculations, theoretical analysis, and experimental measurements. The numerical simulations will use the boundary integral technique to calculate the interaction and deformation of bubbles. The theoretical work will involve calculating bubble shapes and resulting flow in the limit that bubbles become highly deformed. In both the numerical and theoretical analyses, we will calculate all the components of the volume-averaged stress tensor. We can thus obtain
quantities such as the effective shear viscosity and normal stress differences. We will make the experimental measurements in a large-volume, transparent viscometer that we have designed and built. The experimental measurements can be used to verify and extend results, and will allow us to study macroscopic features of the flows that might result from the non-Newtonian behaviour of the bulk suspension. We will also develop closed-form expressions for all our results that should be transferable to other problems and applications, such as models for eruption processes and lava flow models.

Manga
0124972

Heat and mass transfer across thermal and chemical boundary layers at the top and bottom of the mantles of the terrestrial planets govern the chemical and geodynamic evolution these planets. The dynamics of the top, lithospheric boundary layers of terrestrial planets are dominated by multi-mode (brittle/ductile) rheological behavior, e.g., plate tectonics on Earth and immobile lithosphere on Mars, which are at least readily observed if not completely "understood". Although deep mantle dynamics are less accessible to observation, there are still seismological, mineral physics and geochemical data that provide constraints on mantle dynamics. Near the core-mantle boundary, flow probably involves both a thermal and chemical boundary layer.

Laboratory experiments can play an important role in treating problems involving vigorous multi-component convection in which dynamical interactions across continuous viscosity and density interfaces determine the flow. The investigators will carry out a series of laboratory experiments aimed at achieving a better understanding of the dynamics of mantle flow at the Earth's core-mantle boundary. Over the course of the proposed work they will forge a better fundamental understanding of thermochemical boundary layers in all aspects of mantle convection.

The investigation will focus on two classes of experiments: (1) Basic studies of thermochemical convection to elucidate the coupling of heat transfer and flow across chemical boundary layers, quantify entrainment rates across viscosity interfaces, and better understand the dynamics controlling the formation of thermo-chemical plumes. (2) Focussed studies of plume/plate interactions using controlled large-scale flow as a proxy for the effects of plate motions. The investigators also plan to complement their laboratory experiments with theoretical and 3-D numerical modeling studies. For the latter, the laboratory experiments will form valuable benchmarks.

0209752
Romanowicz

This grant supports an upgrade to the computational equipment in the Berkeley Seismological Laboratory and within the Department of Earth and Planetary Sciences at UC-Berkeley. Equipment to be purchased will include a multi-CPU SunFire server with expanded RAM, a multi-CPU Beowulf cluster of Intel PCs, a RAID system, tape backup system, multiple SunBlade workstations, a large format printer, and various network switches and Ethernet cards. UC-Berkeley will share equally in the cost of this upgrade.
Multiple investigators including Romanowicz (global tomography), Burgmann (geodesy/tectonics), Dreger (earthquake seismology), Manga and Richards (geodynamics), and their students, will immediately benefit from these upgrades.
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The investigators seek to advance the creation of a Cooperative Institute for Deep Earth Research (CIDER). This award will provide funds to hold a series of 2 workshops over a period of one to two years whose goal will be to define the scope and activities of a possible future CIDER. The workshops will be interdisciplinary in nature and will address the question of global Earth structure, evolution, and dynamics. Participation will be open to the community. The direct product of each workshop will be a report listing the key questions identified during the workshop, whose resolution requires an interdisciplinary approach, as well as recommendations for the activities and structure of the future CIDER. These documents will then be used as a basis for the preparation of a detailed proposal for the establishment of CIDER.

COLLABORATIVE RESEARCH: Physical Properties of Bubble- and Crystal-bearing Melts and their Implications for Eruption Dynamics: Integrated Theoretical, Experimental and Field-based studies

EAR-0207362; EAR-0207471
PIs: Cashman&Wallace; Manga

Magma must ascend to the Earth's surface prior to erupting. Field and theoretical studies over the past decade have shown that the rate of magma ascent plays a critical role in determining the style, and violence, of the ensuing eruption. This dependence results from physical changes that the magma undergoes as it ascends (decompresses). Bubbles nucleate, grow, and coalesce during decompression; crystals may also nucleate and grow. The presence of bubbles and crystals, in turn, affects the magma's ability to flow (its rheology), and thus its continued ascent. For this reason, development of an accurate model of magma ascent and eruption requires that we understand both the distribution of bubbles and crystals as a function of depth below the Earth's surface and the effect of bubbles and crystals on magma rheology. We propose to address both of these questions through a combination of experimental, theoretical and field-based studies. Our specific goals are: (1) to determine the effect of suspended crystals on the rheology of bubble-bearing melt; (2) to use the bubble structure of volcanic samples to estimate shear (velocity) profiles across volcanic conduits; and (3) to examine the permeability (bubble-interconnectedness that permits gas escape) of volcanic clasts as a function of both their bubble and crystal content.

Pyroclastic flows are among the deadliest of volcanic phenomena because of their high velocities, long run-out distances, high temperatures and large volumes. It has been suggested that their long run-out distances could be due to fluidisation. The fluidising gases are also probably responsible for the elutriation of fines and the generation of the giant co-ignimbrite plumes that override moving flows. These plumes produced the most historically significant injections of aerosol and ash into the stratosphere. Interestingly, only relatively small airflow velocities are necessary to fluidise volcanic ash. The goal of this project is to study with an experimental approach the fundamental processes and variables that affect airflow generation within beds of hot fragments that deform because of shear stresses and/or expand because of particle collisions. Of particular interest is whether ambient air is ingested by expanded beds of hot particles and whether this airflow can fluidise and/or elutriate the fines whose presence between larger rock fragments can affect the mobility of pyroclastic flows. The apparatus that will be used for the experiments produces scale models of pyroclastic flows whose temperature, interstitial fluid pressure and interstitial fluid velocity can be monitored using thermocouples, pressure transducers and flowmeters respectively. Scaling dimensionless parameters will be used to relate the processes in the lab to those in nature. This project will lead to a better understanding of pyroclastic flows dynamics and if thus of importance in the mitigation and forecast of volcanic hazards. This project will be carried out by one postdoc and will provide training for graduate and undergraduate students. In order to involve a larger number of persons and broaden the perspective of the research, a graduate level class based on the topics addressed in this proposal will be offered. This project will also lead to new interdisciplinary collaborations between the engineering and volcanology communities.

One of the most important unresolved problems in physical volcanology is understanding what controls the style of volcanic eruptions, and in particular, the transition between effusive and explosive eruption styles. Currently, this transition is thought to be controlled by two key processes: fragmentation and degassing. Through fragmentation, magma is broken into discrete pieces. The viscous magma containing melt and bubbles is thus transformed into a much less viscous gas flow that can erupt rapidly and explosively. Degassing refers to the loss of dissolved and exsolved volatiles from the magma. Because the driving force of eruptions is often dominated by the expansion of exsolved gases, degassing should act to suppress explosive eruption. The main goal of the project is to determine experimentally the relationship between fragmentation and degassing during the rapid decompression of magmas. The experiments will be done in a shock tube apparatus, designed and built at the University of California, Berkeley. Analogue fluids will be used in order to control properties of the fluids, bubbles, and bubble growth. The experimental study will allow the determination of the relative importance of 1) preexisting bubbles, 2) exsolution, 3) conduit geometry, and 4) decompression rate on the processes that lead to explosive eruption. The experimental results will be interpreted in the context of theoretical models, which will then allow the scaling of laboratory results to volcanoes.

The most important long-term impact of this work will be a better physical basis for estimating hazard. As a specific example, one implication of the experimental results obtained so far is that the bubble content of magmas is the primary control on whether rapid decompression will lead to explosive eruptions. Determining the vesicularity of domes or subsurface magma bodies (using some remote method) can thus be used to estimate the hazard posed by these magma bodies. This project will provide a training opportunity for a graduate student, a postdoc, and an introduction to research for undergraduates. Outreach will take place through classes at UC Berkeley, scientific conferences and refereed publications. It is expected that this project to lead to new interdisciplinary collaborations between the engineering and volcanology communities.

The ultra-low velocity zone (ULVZ) is a thin ( ~10 km) layer in some regions of the lower-most mantle immediately above the boundary with the outer core that is characterized by a dramatic reduction in seismic wave speeds. The cause of this reduction in wave speed is uncertain, but likely possibilities include a small degree of mantle melting and chemical heterogeneity created by reactions between silicate minerals in the mantle with iron in the core. Previous, lower resolution studies that characterized the geographic extent of the ULVZ have hinted at large regional patches, however, recent, higher resolution observations made by members of this group have revealed a potentially smaller-scale structure than originally thought. A small, isolated pocket of more-dense ULVZ material was discovered in a region that was previously thought to contain a much larger, continuous ULVZ layer. Work proposed here involves a collaboration of seismologists and both numerical and laboratory geodynamicists at Arizona State University and the University of California Berkeley. The ultimate goal of this work is to determine how upwelling mantle plumes originating from the core-mantle boundary affect the local geometry of the ULVZ, and one exciting possibility to examine is whether seismically detectable pockets of ULVZ can be used as markers to determine the source region for nearly seismically-invisible mantle plumes. On the seismology front, the ULVZ will be studied at much higher resolution than before with the goal of determining whether previously-thought-continuous ULVZ regions are instead composed of isolated pockets of more-dense regions. Geodynamically, numerical and laboratory experiments will be used to determine whether observed isolated pockets of ULVZ material are related to mantle plumes, and if so, what is the relationship between the morphology of ULVZ material and the flow patterns associated with mantle plume source regions? Finally, proposed work will focus on determining whether the dynamically-predicted and observational constraints can be used to differentiate between competing hypotheses of partial melting and chemical heterogeneity as a cause of the ULVZ.

Inside volcanoes, the formation of bubbles (vesiculation), the breaking of magma into discrete pieces (fragmentation), and the loss of gas in bubbles from ascending magma (degassing) are the key processes that control the dynamics of the erupting magma. The ultimate goal of this project is to understand how these processes interact and are reflected in the features of a volcanic eruption and the products it produces.

It is proposed to perform experimental and numerical studies of eruption dynamics and modeling of eruption products in order to understand what controls whether an eruption will be explosive or effusive. The research tasks will include measurements of volatile contents and gradients in obsidian from both explosive and effusive eruption to determine the timescales for vesiculation, degassing and fragmentation. In addition, the team will develop conduit models to understand the competing and interacting effects of flow, degassing, and changes in magma rheology. It is planned to continue experimental studies of the effects of bubbles and crystals or the rheology of suspensions to allow for better models of rheology to be included in conduit flow simulations.

This project provides graduate training for three students, supports international collaboration, and interaction with a new user facility at the Advanced Light Source. Because the project is aimed at understanding the controls on eruption style and the relationship between conduit processes and features of erupted materials (texture, volatile content), results will provide a better basis for estimating volcanic hazard, both from a modeling perspective, and from measurements on historic and prehistoric deposits.

Hydrologic responses to earthquakes, such as increases in steam flow or changes in the water level in wells, are not uncommon. Hydrologic responses are important because they provide unique insight into the coupling of hydrologic and tectonic processes at spatial and temporal scales that are otherwise difficult to study.

The origin of hydrologic responses to earthquakes has been the subject of controversy, in large part because there are many models to explain observations and almost no measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.6 earthquake occurred near the Alum Rock springs, California. The PI monitoring these springs for the past 5 years in order to provide a benchmark for post-seismic changes in discharge and water composition. Over the first 5 days following the earthquake he documented a three-fold increase in discharge. The Alum Rock springs discharge along one strand of the Hayward fault. They discharge water that is a mixture of local meteoric water and connate waters expelled from depth.

The PI will use stable isotope analyses of water samples collected over a 3 month time period following the earthquake in order to test proposed models for the origin of the increased discharge. Because the spring water at each spring is geochemically distinct it should be possible to document changes in fault zone plumbing. It will also be possible to determine whether the source of the excess water flowing from the springs originates at depth, or in the shallow subsurface.

This project offers an interdisciplinary opportunity to understand fault zone structure and evolution. In particular it will provide new (and probably unique) constraints on the role of fluids in fault zone processes. The PI will integrate the monitoring of the springs with courses taught at UC Berkeley, including freshman seminars, undergraduate-level geodynamics, and graduate level classes. The results will also be communicated with the managers of Alum Rock Park where the springs are located. The park is a popular destination for local residents and K-12 student field trips. The springs are the main draw of the park and this work can be used to update interpretative signs and displays.

Explosive volcanic eruptions are some of the most energetic flows on the planet, the largest of which can have global impact. The more common, smaller, events are a proximal hazard and still encompass scales of several kilometers. Despite their large size and long duration, mass and energy transfer in these flows are fundamentally controlled by processes at much smaller spatial and temporal scales, where individual particles interact with each other, with gas, or with the surface over which the flows travel. Our ability to predict large-scale behavior of volcanic flows can ultimately be limited by our understanding of very small-scale, or microphysical, processes. This proposal examines a suite of particle-scale mass and energy transfer mechanisms in the laboratory with the aim of understanding the physics of these processes and to incorporate them into large-scale simulations of explosive volcanic eruptions. One of the long term goals of this effort is to provide a technology for students, scientists and civil officials to better understand hazards during times of volcanic unrest.

Advances in computational power and algorithm design enable detailed studies of the turbulent structures that develop in explosive volcanic eruptions. However, even with increases in computational resources, achieving resolution below meter-scale in large-scale three-dimensional simulations may never be possible. Accounting for subgrid-scale physical processes requires developing constitutive relationships for volcanic materials and conditions. Past work on steam explosions has shown that subgrid models developed from experiments can be readily coupled to multiphase numerical simulations. More importantly, these subgrid relations are critical for predicting the dynamics reflected in volcanic deposits; models that neglect subgrid processes can fail to produce the energy transfer manifest in volcanic deposits by several orders of magnitude. This work will focus on 1) heat transfer between particles and gas, 2) comminution and agglomeration in active flows and the impact of a evolving grain size distribution on the dynamics of flows, and 3) particle-boundary interactions, and in particular the role of resuspended particles from the bed. All of the proposed experiments will be conducted with materials and conditions similar to those in natural flows, minimizing the potential difficulties with scaling to large-scale multiphase flows. In the methodology proposed, the numerical models are integrally connected to the experimental data. The dual approach emphasizes the strength of both techniques: the strength of numerical models is the ability to solve non-linear, complexly coupled equations and determine emergent behavior, and the strength of the experiments is to understand in detail the physical processes operating at small scales.

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)

The relatively low shear modulus and high temperature of Earth's ultralow-velocity zones (ULVZ) imply that these thin (5-40 km thickness) regions at the core-mantle boundary (CMB) may be partly molten. In order to maintain the cooling rate necessary to drive a dynamo by convection, Earth's ancient core must have been hotter than at present and the lowermost mantle would therefore have been more extensively melted. It has been hypothesized that the higher density of melt relative to solids in the deepest mantle stabilized this molten layer, forming a dense basal magma ocean (BMO) that appeared early in Earth's history and whose remains are at present the ULVZs.

The existence of a BMO has large effects on the dynamics and differentiation of the deep Earth. Incompatible elements would have been sequestered into the melt by fractionation, while the chemical signature of solids crystallized from the BMO would be governed by the phase diagram. This crystallization signature should appear at Earth's surface in volcanic products from deep-seated mantle plumes. Other structures in Earth's lowermost mantle such as "chemical piles" may be formed or modified by BMO crystallization. The presence of a BMO will also enhance the extent of core-mantle chemical interactions relative to a solid lowermost mantle, possibly leading to the formation of a buoyant layer at the top of the core that is enriched in light elements.

This project aims to further explore the consequences of a BMO by developing a two-phase dynamics model that will be used to better constrain the dynamical evolution of a BMO, to address several questions raised by the BMO hypothesis, and to begin to test the hypothesis with geochemical data and seismological observations. The effects of a buoyant stratified layer at the top the core produced by reactions between the BMO and core will also be explored using a numerical dynamo model to test whether features of dynamos in such cores are compatible with geomagnetic observations.

The project will provide two years of support for a post-doctoral researcher, who will benefit from interdisciplinary training, and involves direct international collaboration among researchers in 4 different countries (United States of America, United Kingdom, France, and Canada). Most will be new collaborations. The two-phase flow models can be applied to a large variety of mush-slurry systems in other disciplines, such as the evolution of crustal magma chambers and volcanic systems. The code will be used in upcoming benchmark exercises, a time consuming but essential aspect of code development and modeling. The code will also be made available to the broader research community for use in other projects.The relatively low shear modulus and high temperature of Earth's ultralow-velocity zones (ULVZ) imply that these thin (5-40 km thickness) regions at the core-mantle boundary (CMB) may be partly molten. In order to maintain the cooling rate necessary to drive a dynamo by convection, Earth's ancient core must have been hotter than at present and the lowermost mantle would therefore have been more extensively melted. It has been hypothesized that the higher density of melt relative to solids in the deepest mantle stabilized this molten layer, forming a dense basal magma ocean (BMO) that appeared early in Earth's history and whose remains are at present the ULVZs.

Glassy obsidian (rhyolite) lava is one of the best known igneous rocks to the public, but because obsidian flows have not occurred historically, there are no clear answers to such basic questions as how fast do such lavas spread across the land or how long do such eruptions last. Answers to those questions may, however, be recorded in micro-textures in the obsidian, such as the sizes, shapes, and orientations of small crystals, known as microlites, which grew as the lava erupted and flowed away from the vent. Such crystals also commonly occur in discrete bands within obsidian, probably related to the way rhyolite magma flows. It is known that such crystals grow in response to cooling and gas loss from the erupting magma, and their textures can differ strongly in response to changing rates of cooling and gas exsolution. Those textures have not, however, been quantified for obsidian flows. Field studies of the distributions of microlite textures, in conjunction with experimental and analytical studies reproducing their growth in the laboratory will be used to relate microlite textures and eruption dynamics to determine how fast obsidian lava extrudes at the surface and flow outwards. Those answers will aid in understanding the hazards associated with obsidian lavas, which occur worldwide and in all tectonic environments, with especially large outpourings in Yellowstone National Park, Wyoming. In fact, much of the present-day landscape of Yellowstone National Park is shaped by obsidian lavas that cover 100s of square kilometers, some of which erupted in the past 100,000 years. Obsidian lava eruptions are one of the most likely types of magmatic eruption to occur in the future at Yellowstone National Park, and so understanding their eruptive behavior will aid scientists in responding to the next eruption.

To establish how microlite textures record the eruption and flow of obsidian lava, an integrated database of micro-textural measurements from multiple lavas will be established, focused on 1) multiple lavas of similar volume, and 2) lavas that span a large range in volume. The first set will establish commonalities between flows, whereas the second will establish how conditions change to produce greatly different outpourings. Those rhyolite flows come from several distinct volcanic centers within the United States, located in California, Idaho, and Wyoming. Textural data of microlites (types, numbers, sizes, orientations) and flow banding (spatial distribution, widths) will be examined in all flows, and linked to magma ascent and degassing histories through decompression experiments. Those experiments will be designed to not only infer ascent rates and degassing histories of targeted lavas, but also to explore broader questions about the impacts of temperature, fluid composition, and crystal content on crystallization kinetics in rhyolite magma. It will be also critical to establish how long it takes for such lavas to cool at the surface. A novel approach that will be pursued will be to examine spherulites, radiating masses of microlites commonly found in obsidian lava. Spherulites are known to grow in response to cooling, and so their sizes, distributions, and compositional variations can establish how obsidian lava cools. Spherulite growth models will be developed by measuring size distributions of spherulites with high-resolution X-ray Computed Tomography and analyzing multi-element compositional profiles around spherulites with synchrotron-sourced infrared (water) and laser-ablation ICP-MS (cations), which will allow the cooling history of a sample to be extracted and placed into context of lava emplacement.

The PIs propose to develop CIDER-II, (Cooperative Institute for Dynamic Earth Research) as an "Institute without Walls" enabling Earth Scientists of all disciplines to share their knowledge in studying the fundamental processes responsible for plate tectonics and associated natural hazards, in particular earthquakes. CIDER II will facilitate concerted multi-disciplinary investigations involving leading researchers across a broad range of Earth Science disciplines. It will:
* Foster synergies between individuals and small groups of interdisciplinary researchers in
tackling the most important and difficult unsolved problems in solid earth science;
* Provide an environment for the development of new ideas that will help identify the next generation of critical experiments and observations, and to build appreciation and support for them;
* Provide a venue for cross-disciplinary education of scientists at all career levels.

CIDER's goals are to help improve fundamental understanding of the Earth's evolution and present dynamics through a multi-disciplinary approach. It has been 40 years since the acceptance of plate tectonics theory, but no definitive agreement has yet been reached among geoscientists on the fundamental nature of the global dynamic processes that drive plate motions. The indication that a transformative approach is needed and is likely to be successful comes from new interpretation of global seismic tomographic models, indicating the existence of multiple depth domains in the Earth that show different properties of heterogeneity as a function of wavelength and depth. This suggests each depth domain has its own dynamics, but with some degree of coupling among them. Generally, a much more complex problem than has been considered until now.

Meanwhile, a new generation of disciplinary tools is becoming available that are providing unprecedented views of the Earth's interior. Major infrastructure efforts are currently under way: Earthscope's USArray (http://www.earthscope.org) provides seismologists with a high resolution "window" into the lithosphere, deep mantle and core over the North American continent; COMPRES (http://compres.us) allows mineral physicists to perform advanced measurements on mineral properties at the high P-T conditions relevant to the Earth's deep interior, and to compare them with results of "first principles" calculations. CIG (http://www.geodynamics.org) provides geodynamicists and seismologists with a unified, state of the art framework for computations of mantle and core convection and seismic wave propagation. Extensive GPS networks and satellite observations are revolutionizing the fields of geodesy and geomagnetism (e.g. EarthScope's Plate Boundary Observatory, Oersted, Champ, GRACE and Swarm). Paleomagnetic data are being assembled into the MagIC database (earthref.org/MAGIC/). In geochemistry, the enormous volumes of high quality chemical and isotopic data gathered over the past 25 years are now part of systematic and broadly accessible databases (PETDB:www.petdb.org, GEOROC georoc.mpch-mainz.gwdg.de/georoc), and ever-improving analytical techniques are providing new perspectives on mantle processes at scales from micrometers to thousands of kilometers. Given the enormous amount and diversity of observations becoming available, a significant leap in the understanding of the constitution and evolution of our planet can be expected, if we can identify and focus on the key issues that necessarily span across disciplines, and build effective inter-disciplinary bridges to solve them.

The role of CIDER-II will be to provide mechanisms for community evaluation, validation, problem reconciliation and consensus building. In each year, the activities of this "Center without walls" will be organized around a principal multi-disciplinary theme. The kick-off for each CIDER-II "theme" will be a 6-week summer program aimed at bringing together in one place researchers across disciplines, and across career levels, to define key questions that are ripe for synthesis and/or for a concerted multi-disciplinary research effort. CIDER-II will also provide support for working groups formed to address particular practical issues identified as ripe for synthesis. CIDER is inherently a broad impact program: it facilitates cross-education of earth scientists at any level in their career; it aims at educating a new generation of Earth scientists with a breadth of competence across disciplines required to make progress in understanding the dynamic earth. CIDER's web resources, including posting and webcasting of lectures given during the summer programs, as well as planned web forums and open publications, is designed to reach the entire community of earth scientists. CIDER will impact undergraduate education by producing a more broadly knowledgeable faculty cohort.

Geysers provide a natural laboratory to study eruption processes and the geophysical and hydrological signals that can be measured before, during, and after an eruption. Because they are smaller than volcanic eruptions, and erupt more frequently, they provide a rare opportunity to collect abundant data and develop approaches for integrating and interpreting measurements.

About 3 million visitors to Yellowstone witness the wonders of geyser eruptions. Explanations for these phenomena, however, are limited or lacking. Geyser-like behavior of water and hydrocarbons has also been observed on the ocean floor and at mud volcanoes. Thus improved understanding of geyser behavior may yield insight into other self-organized, intermittent processes in nature that result from localized input of energy and mass. Insights from studies of geysers can also be translated to volcanic systems. This project will integrate field measurements, laboratory studies, and numerical simulations of multiphase flow in geyser systems to address the following basic questions about the geysering process: How does conduit plumbing affect eruption initiation and interval? Do eruptions begin at the top or bottom of the conduit? How many conduit volumes erupt per eruption? Do non-condensable gases play a role in eruptions? Which external processes (e.g., tides, variations in barometric pressure, earthquakes) and internal dynamics (e.g., duration of preceding eruption) influence the interval between and duration of eruption? How are geyser conduits recharged? When and where does vapor form? Answers to this question may offer new insight into triggered seismicity and volcanic eruptions.

Explosive volcanic eruptions are some of the most energetic granular flows on the planet, the largest of which can have global impact. Even the more common, smaller, events encompass scales of several kilometers. However, mass and energy transfer in these flows are fundamentally controlled by processes at much smaller spatial and temporal scales, where individual particles interact with each other, with gas, or with the surface over which the flows travel. Our past work on steam explosions, ash production, and heat transfer have shown that subgrid models developed from experiments can be coupled to large-scale numerical simulations. More importantly, these subgrid relations are critical for predicting the dynamics reflected in volcanic deposits and in ash dispersal patterns; models that neglect subgrid processes can fail to produce the energy transfer manifest in volcanic deposits by several orders of magnitude. Our ability to predict large-scale behavior of volcanic flows can ultimately be limited by our understanding of very small-scale, or microphysical, processes. In this study, the investigators will examine a suite of particle-scale mass and energy transfer mechanisms in the laboratory with the aim of understanding the physics of these processes and to incorporate them into large-scale simulations of explosive volcanic eruptions.

This project will support an ongoing effort in predictive computational volcanology. Specifically they team will focus on 1) heat transfer between particles and gas at high Reynolds numbers and using clast cooling proxies to examine entrainment in pyroclastic density currents, 2) particle deposition and resuspension, including the role of particle impacts in generating depositional features, 3) large-scale experiments of gas-particle density driven flows, and 4) and the production of fine ash particles in the conduit and in pyroclastic density currents. All these processes contribute to production and dispersal of ash and larger pyroclasts to the immediate environment of the volcanic edifice and also to the wider dispersal of ash in the atmosphere. Understanding the physics of these processes is crucial in determining the potential aviation, climactic, and local hazards of eruptions. All of the proposed experiments will be conducted with materials and at conditions similar to those in natural flows, minimizing the potential difficulties with scaling to large-scale multiphase flows. In the methodology proposed, the numerical models are integrally connected to the experimental data. The strength of numerical models is the ability to solve non-linear, complexly coupled equations and determine emergent behavior, and the strength of the experiments is to understand in detail the physical processes operating at small scales.

The objective of this program is to provide a combination of financial support, academic enrichment, mentoring, professional development resources, and leadership preparation to twenty-six talented students with financial need so that they can navigate successfully through their undergraduate years in science or mathematics at the institution. To support student achievement at the highest academic level, scholarship recipients are embedded in a mentoring network of peers, near peers, faculty, professional scientists and alumni who are further advanced on the academic pathway. The financial support relieves talented students with financial need of the obligation to work and take out loans while they make their way through a first class education in the mathematical or physical sciences to graduate school or the scientific workforce.

Intellectual Merit:

This project opens the door for academically talented students from diverse backgrounds with demonstrated financial need to key fields of modern science. By focusing on potential for leadership and success, the program encourages the scholarship recipients to envision, plan for, and prepare for graduate school or productive and competitive careers in the scientific workforce. Priority is being given to supporting the preparation and advancement of students with interest, academic merit, and indicators of determination to succeed in the fields of Astronomy, Chemistry, Geology, Geophysics, Earth and Planetary Science, Mathematics, Applied Mathematics, Physics, and Statistics. During the freshman and sophomore years, scholars become members of and benefit directly from the formal networked community of scientists. Leadership and talent development opportunities are being introduced during the junior and senior years.

Broader Impacts:

The project prioritizes the recruitment and retention of diversity students, using the legal California post-Proposition 209 definition to include historically underrepresented minorities, women, students with disabilities, and students who are the first generation in their families to go to college. To achieve this, the project works closely with the Office of Admissions and the Financial Aid Office to identify eligible students who also increase diversity in the mathematical and physical sciences. The project team then engages in active partnership with programs that focus on the recruitment and advancement of students from groups underrepresented in science and are administered by the Mathematical and Physical Sciences Diversity and Education Center. These include the Berkeley Science Network and the NSF-Berkeley Science Connections, both of which are designed to facilitate the advancement of underrepresented minorities in the mathematical, physical and computer sciences from high school through post-doctoral levels; The Compass Project, which fosters an inclusive community in the physical sciences at the undergraduate level; and the Society for Women in the Physical Sciences, a university supported program run by female graduate students in Physics, Astronomy, Earth and Planetary Sciences and Biophysics, whose goals are to encourage women and minorities to study the physical sciences and to create a friendly and supportive environment in these departments for all students.

Pyroclastic density currents are hot and fast-moving mixtures of solid particles and gas produced by explosive volcanic eruptions or the collapse of lava domes. They travel great distances, pose substantial hazards, and alter landscapes. The processes governing the movement of, and transport in, pyroclastic density currents are not well understood quantitatively. Even conceptual models remain controversial. Basic questions remain about how hills, ridges, and valleys alter and direct pyroclastic density currents and about how air mixes into the currents. These key processes control current speed, direction, and injection of ash into the atmosphere. The long term outcome of better understanding pyroclastic density currents is a scientific foundation for assessing the hazards they pose.

This project will use dynamically scaled laboratory experiments, in particular their interaction with topography, to understand pyroclastic density current dynamics. This will be accomplished by imaging the three-dimensional velocity and concentration fields inside modeled dilute pyroclastic density currents, and quantifying the entrainment of air and sedimentation of particles. This understanding will improve our ability to relate field deposits to the dynamics of these currents. The experimental setup is designed to permit a large number of experiments and hence to explore relationships between parameters and processes.

Geysers are springs that intermittently erupt mixtures of steam and liquid water. They are popular tourist attractions, with a few million people watching geysers erupt in Yellowstone National Park each year. Geysers are the surface expression of geothermal systems and provide insight into heat and fluid flow in volcanically active areas. Geysers also provide a natural laboratory to study eruption processes and the geophysical and hydrological signals that can be measured before, during, and after an eruption. Because they are smaller than volcanic eruptions, and erupt more frequently, they provide an opportunity to collect abundant data and develop approaches for integrating and interpreting measurements. Geysers and their deposits have been studied to understand life in extreme environments. Geyser-like behavior of water and hydrocarbons has also been observed on the ocean floor and at mud volcanoes. Thus improved understanding of geyser behavior may yield understanding into other self-organized, intermittent processes in nature that result from localized input of energy and mass.

Despite two centuries of scientific study, explanations for geysering phenomena are limited or lacking. This project will integrate field measurements, laboratory studies, and numerical simulations of multiphase flow in geyser systems to address the following basic questions about the geysering process: Why are geysers so rare? How does conduit plumbing affect eruption initiation and the interval between eruptions? Why and how do geysers interact with each other? Which external processes (e.g., tides, variations in barometric pressure, temperature variations, wind speed, earthquakes) and internal dynamics (e.g., duration of preceding eruption, plumbing geometry) influence the interval between and duration of eruptions? Answers to these questions may offer new insight into triggered seismicity, hydrothermal explosions, and volcanic eruptions.

Volcanic eruptions transport magma from reservoirs deep underground to the surface through conduits. Because volcanic processes occur underground, or are very dangerous to approach, many key aspects of volcanic eruptions are difficult to study with direct observations. Here, a new technology called synchrotron X-ray micro diffraction (microXRD) will be used to document deformation preserved in crystals that were transported within volcanic eruptions. The microXRD technique measures the amount of strain and preserved stress in the crystal lattice of those crystals. Volcanic stresses are important because they control eruption processes, including magma movement and explosivity. The first step to interpreting residual stress is to identify the specific processes that strain volcanic crystals. To this end, volcanic simulation experiments will be performed to deform crystals. MicroXRD will be used to analyze the experimental products and then compare results with natural crystals. This set of experiments and measurements will address the "How" and "Why" of volcanic eruptions. The standards and techniques developed in this project will enable application of microXRD to other disciplines, including Tectonics, Meteoritics, and Materials Science.


The forces that act on magmas control volcanic processes. Consequently, crystals from volcanic eruptions are strained in the magma chamber, conduit, and during emplacement. Synchrotron X-ray micro diffraction (microXRD) will be used to quantify the magnitude of those strains by analyzing crystal lattice deformation with submicron spatial resolution on a suite of quartz, magnetite, and zircon crystals from the Long Valley and Yellowstone calderas. Measuring the magnitude of strains and using microstructure maps across crystals will reveal how strain is produced and preserved in crystals. Next, the preserved strains will be translated to causal stresses using the elastic constants of the mineral and Hooke's law. The goal is to quantify volcanic stresses in different volcanic environments and assess the forces and the time scales over which those forces act. MicroXRD has exceptional potential as an emerging technology in the geological sciences, but there is limited physical and theoretical infrastructure to interpret datasets. For this reason, high-temperature experiments will be performed to simulate stresses in volcanic environments using unstrained synthetic crystals, and assess the preservation of stress in strained natural crystals. Experimental products will be analyzed by microXRD and used to identify and/or eliminate sources of deformation.

Low-silica 'mafic' magmas are the most common magmas to erupt on Earth. Because their viscosity is low, they usually form lava flows or weak explosive eruptions. However, mafic-composition volcanoes can produce much stronger, Plinian-style eruptions capable of dispersing ash fall over thousands of square kilometers, and producing deadly, landscape-altering ash flows that travel tens of kilometers from source. Despite their potential impact, the mechanisms responsible for generating mafic, Plinian eruptions are not understood. This project will benefit society by constraining the causes and consequences of such eruptions, which has global implications for the millions of people living at risk from mafic volcanic centers including the currently active Kilauea volcano in the USA. Two Boise State University (BSU) PhD students will be trained by the five participating scientists on the team, advancing discovery and understanding while promoting teaching, training, and learning. Undergraduate geoscience students from the Universidad de Concepcion (Chile) will be included in the field work and research, broadening participation of under-represented groups. The results and experience of the research team will be shared on the BSU magmatic and volcanic studies group Facebook page through a series of blog post and short videos of our field work that document the key elements of discovery associated with the project. Finally, the investigators and students will incorporate samples, stories, images and videos from the work in Chile into local and regional outreach efforts.

This project targets the 13.4_ka (~12 km3 DRE) and ~12.6 ka (<1 km3 DRE) mafic eruptions at Volcan Llaima, Chile, which produced extensive ash flow deposits found radially around the volcano. The difference in eruption sizes permits investigation of processes that promote large-volume, caldera forming mafic eruptions versus smaller volume Plinian mafic eruptions. A full suite of diverse but complimentary methods, including petrology, geochemistry, physical volcanology, decompression experiments, and rheology experiments, allows the research team to address the broad, fundamental research question of what magmatic and crustal conditions promote and trigger mafic, Plinian eruptions. More specifically, spatially and stratigraphically constrained petrologic and geochemical studies will allow us to investigate magmatic conditions during and prior to eruption, such as compositional variability of the magma and changes in chamber temperatures, pressures, and gas content. Establishing variability in these conditions will permit reconstruction of the magma plumbing system. A combination of all methods are used to constrain conduit conditions that promote high explosivity for mafic melts, including the interplay between ascent rate and degassing of the magma, as well as changes in magma rheology that prevent gas loss, promoting higher explosivity. The results of this work will have implications for understanding explosive mafic eruptive processes that extend to mafic centers worldwide, including both large-volume and small-volume mafic, Plinian eruptions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

This project will develop a new probe to measure the amount of heat coming out of the ground beneath lakes. The probe will overcome current limitations by (1) enabling visual site selection so that researchers know where and how the probe is placed in the lake floor environment and pin-point important lake floor features such as gas seeps and chemosynthetic communities, (2) providing real-time data to assess data quality and site evaluation, and (3) monitoring temperature changes over time that might arise from changes in lake temperature. The probe will be deployed and tested in Mono Lake, California. Mono Lake has hosted the youngest volcanic eruptions in the region. There are, however, currently no heat flow measurements within the lake to constrain recent volcanic activity and volcanic hazards. The measurements may reveal the extent of magma bodies that connect the subsurface to the volcanic eruptions seen at Earth?s surface. This project will be integrated into a summer field camp so that 20 students can participate in the measurement campaign and data interpretation. This project provides an opportunity to test new instrumentation that would be useful in a broad range of settings.

The prototype geophysical probe, called the LTMP (Lake Thermal Monitoring Probe) consists of a compact (1-3 m long), lightweight (<20 kg), camera-mounted Lister-type heat flow probe designed for deployment by only two people on a small (~5 m) vessel in a lake bottom. The probe will be designed to provide both real-time lake floor video for site selection, and real-time subsurface temperature monitoring for up to one year, with data continuously beamed back to researchers. If the new probe works, it will provide a new high-resolution tool for measuring heat flow and fluid flow changes in complex geologic settings like caldera lakes, revealing how heat flow below lakes is coupled to other geosystems and hazards (e.g., the atmosphere, groundwater, volcanoes, earthquakes).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Advances in disciplinary tools and major infrastructure efforts have fueled impressive progress in our ability to understand the dynamics of plate boundaries and the associated hazards to life and infrastructure. New data sets and new methodologies offer valuable insights, yet many aspects of plate boundary evolution are still poorly understood. Part of the impediment to progress is due to the disciplinary nature of research. A more integrated approach that leverages the knowledge and latest achievements in each of the relevant disciplines is needed to generate new ideas and to identify new observations that distinguish between competing hypotheses. This award supports a summer program for the Cooperative Institute for Dynamic Earth Research (CIDER) on the GeoPRISMS-driven theme of fluid and magma transport. CIDER seeks to lower barriers to integrated research by promoting cross-disciplinary education of researchers at all career levels. The team also intend to develop a workforce that can more effectively engage in interdisciplinary research with the goal of enabling more rapid progress on an important and unsolved research problem.

The proposed four-week summer program brings together a cohort of senior graduate students and postdocs from institutions across the country to tackle the fundamental questions about the evolution of plate boundaries. This topic is central to the basic paradigm of plate tectonics and understanding the role of fluids and magma has been a long-standing challenge. Senior participants from various US institutions, and representing a range of disciplines, serve as instructors and mentors for group research projects. The first two weeks of the program are devoted to lectures and tutorials, covering the basic tools and approaches of the various disciplines. The second two weeks are used to develop research projects in groups with a good mix of disciplinary expertise. The outcome will be a better understanding of plate boundaries, including key questions about the cycling of water and carbon through the Earth system, which regulates the long-term stability of climate.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

The Yellowstone hydrothermal system hosts the largest number of geysers on Earth. These natural wonders attract millions of visitors each year. Despite a history of scientific investigation spanning over 150 years, fundamental questions about geysers remain: What structures are required to create geysers? Why do some geysers erupt regularly and others do not? What controls eruption characteristics such as the volume erupted, the interval between eruptions, and the height to which geysers erupt? Can eruptions be accurately predicted? This project aims to address these questions by collecting and analyzing interdisciplinary data from few iconic geysers in Yellowstone, including Old Faithful and Steamboat. Using naturally excited ground vibration observed across dense seismic arrays, the subsurface plumbing structure will be imaged and the thermal state within will be inferred during each stage of the eruption cycle. By mimicking the natural geysers, laboratory geyser models will be built to examine how plumbing geometry and other factors give rise to eruption characteristics. Through the research, the project will support undergraduate and graduate education and the scientific findings will be disseminated through the education and outreach platforms of National Park Service and USGS Yellowstone Volcano Observatory.

Geysers are springs that intermittently erupt mixtures of steam and liquid water. They provide a window into the transport of mass and energy in hydrothermal systems. To understand how and why geysers exist and erupt the investigators will use a multidisciplinary approach to study the iconic geysers of Yellowstone National Park, in particular, Old Faithful, the geysers of Geyser Hill, and the world’s tallest geyser, Steamboat. They will use dense temporary seismic arrays and novel interferometry-based array analyses to track subsurface hydrothermal tremor migration and hence the evolving thermodynamic conditions before, during, and after eruption. Similar analyses will be used to image the plumbing system of geysers and deeper geological structures that enable geysers to exist and identify changes in those structures over time. Laboratory models and in situ pressure and temperature measurements will be used to interpret seismic observations and develop a generalized understanding of geysering phenomena and signals. Together, a combination of seismic data and models will be used to forecast eruptions, including their timing.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.