Distinguished Lecturer Series 2019-2020
COMPRES, the Consortium for Materials Properties Research in Earth Sciences announces the speakers for its 2019-2020 Distinguished Lecture series in the field of Mineral Physics. The talks feature topics that emphasize the exciting high-pressure geoscience research being conducted within the COMPRES community and its significance for understanding fundamental Earth and planetary processes.
The primary target audience for these lectures is undergraduates in departments of geology and related sciences at non-PhD granting institutions, but applications from all academic institutions in the U.S. are welcome.
We are pleased to announce that the COMPRES Distinguished Lecturers for 2019-2020 are Rebecca Fischer of Harvard University and Jin Zhang of The University of New Mexico. Their lecture titles, abstracts and bios are below. We invite you to request a visit of a COMPRES lecturer to your institution during the next academic year by following these instructions.
COMPRES will fund all travel costs for the speaker, including transportation, accommodation and meals. There is no cost to the hosting institution. The host colleges or universities will be expected to arrange the talks and provide local logistical support.
The Lecture Program is designed to run from September 2019 through May 2020. Lecturer requests received by October 1, 2019 will be given priority. Later applications will be considered on an as-available basis. In making your request please include:
1. The name of a contact person at your institution for the months of June to August. This is when schedules will be assembled.
2. Contact e-mail addresses and phone numbers.
3. Lecturer preference and flexibility.
4. Preferred semester and/or month for the visit, including flexibility. Also, if this is to be part of a regular lecture series, tell us the day of the week and time of the series.
5. Airport proximity and travel time to your institution
We hope that your Department will be interested in hosting one of these mineral physics lecturers in this academic year.
COMPRES is supported by the National Science Foundation Division of Earth Sciences.
Rebecca Fischer earned her bachelor’s degree in Earth and Planetary Sciences and Integrated Science from Northwestern University in 2009, and her Ph.D. in Geophysical Sciences from the University of Chicago in 2015. She was a National Science Foundation postdoctoral fellow at the Smithsonian National Museum of Natural History and the University of California Santa Cruz from 2015 to 2017. Since 2017, she has been a Clare Boothe Luce assistant professor in the Department of Earth and Planetary Sciences at Harvard University. Her research interests include diverse aspects of the composition, structure, and properties of the Earth’s mantle and core; core formation on Earth, the Moon, and Mars; and terrestrial planet formation. She uses laser-heated diamond anvil cells to recreate the high pressures and temperatures of planetary interiors in the laboratory, and studies the physics and chemistry of core and mantle materials at these conditions, often combining experimental data with numerical simulations of planetary-scale processes.
(1) Using experiments and modeling to recreate Earth’s core formation
The Earth formed through the process of accretion in a series of increasingly large and energetic impacts. These impacts caused melting of a significant portion of the silicate mantle, generating a “magma ocean”, which allowed the metallic core to segregate to the Earth’s center. This process of core formation was one of the most important events the Earth experienced during its formation and early evolution, because reactions between molten silicate and molten metal at high pressures and temperatures as the core was forming set the initial compositions of the core and mantle. This presentation will focus on interconnected experimental and numerical studies of the core formation process and its effects on composition. I will first present results of high pressure, high temperature experiments in which we recreate the process of core formation in the laboratory, allowing us to study the behaviors of major, minor, and trace elements during metal–silicate reactions at these extreme conditions. Then I will present a model of the chemical evolution of the Earth during core formation based on these data, which provides insights into the composition of the Earth’s core and the mechanisms of core formation.
(2) What was the Earth’s mantle like in its hotter past?
The exact thermal history of the Earth’s deep interior is the subject of much debate, but the mantle has likely cooled by a few hundred degrees over the past several billion years, having started out largely molten during the formation of the planet. When the mantle was 200–300 K hotter, it would have exhibited significantly different structure and properties than it does today. This presentation will feature two studies that focus on differences in the mineralogical structure and water content of the Earth’s mantle in its hotter past. I will present new experimental constraints on the phase diagram of olivine at high pressures and temperatures, and discuss implications for the structure of the Earth’s mantle transition zone in the past. I will also present a thermodynamic model of the water storage capacity of the Earth’s mantle and how it has changed as the Earth cooled, with consequences for water cycling between the surface and mantle reservoirs.
Jin Zhang received her B.S. degree from Nanjing University in 2008 and Ph.D. degree in Geology from the University of Illinois at Urbana-Champaign in 2014. After a short postdoc at University of Illinois, she became the COMPRES Chief Technology Officer stationed at the Advanced Photon Source of Argonne National Laboratory. Since July of 2016, she joined University of New Mexico, and held a joint appointment as both the assistant professor at the Department of Earth and Planetary Sciences as well as a senior research scientist at the Institute of Meteoritics. She recently received the Faculty Early Career Development (CAREER) Award (2019–2024) from the National Science Foundation. Her research interest primarily focuses on the physical properties, such as elastic anisotropy, phase transformations of the Earth and planetary materials, and exploring the linkage between the laboratory measurements with various geophysical and geochemical observations. She is also interested in phase equilibrium studies at high pressure-temperature conditions. Her specialty is high-pressure diamond-anvil cell and laser spectroscopy, but also employs multi-anvil presses and micro-analytical techniques for her research.
(1) Hunting for the compositional heterogeneities in the Earth’s mantle: insights from minerals’ elastic anisotropy
Earth and terrestrial planetary bodies are primarily constituted of silicate minerals. The chemical and physical properties of these minerals change as functions of depth and control various dynamic processes of the planetary interiors. Most materials in the planetary interiors are elastically anisotropic. Under dynamic flow fields, the preferred alignment of the mineral crystals are likely to cause the seismically observed anisotropy. The different anisotropic elastic properties of deep planetary materials can be powerful tools that helps us to locate and identify various geochemical heterogeneities in the Earth’s interior. In this talk, I will focus on two interesting problems: 1. The unique anisotropic elastic properties of the recycled oceanic crust and sediment in the Earth’s interior; 2. Generation of the possible large anisotropy in the deep Earthquake generation zone. I’ll link these problems to the elastic properties of clinopyroxene, as well as high-pressure planetary ice phases measured in the laboratory. These measurements provide us unique opportunities to link the observed geophysical anomalies to various compositional heterogeneities and geochemical reservoirs in the Earth’s interior.
(2) Visiting the interface between the upper mantle and transition zone: what does elasticity tell us?
The experimentally determined elastic properties of mantle minerals at elevated pressure and temperature conditions provides a powerful means for us to understand the chemical and physical processes in the Earth’s interior. In particular, the elasticity change caused by various mantle phase transformations are commonly used to explain the observed seismic interfaces between the different layers in deep Earth to the first order. In this talk, I am going to focus on olivine and its high‐pressure polymorphs, and then link the experimental predictions to the seismic observations near the 410-km discontinuity, which is the interface between the upper mantle and transition zone. These studies can bring in additional insights to the deformation mechanisms as well as petrological composition anomalies in the deep Earth interior.