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Cooperative Institute for Dynamic Earth Research (CIDER)

View 2009 File:Romanowicz-intro.ppt CIDER Overview slides

The goals of the Cooperative Institute for Dynamic Earth Research (CIDER) are: (1) To provide an optimal environment for transformative studies requiring a concerted effort of leading researchers from different areas of Earth Sciences: high pressure material science, geodynamics, seismology, geochemistry and geomagnetism, and (2) to educate a new generation of Earth scientists with breadth of competence across the disciplines contributing to understanding of the deep earth. The ultimate goal of CIDER is to develop an integrative conceptual model drawing upon all contributing disciplines to understand the origin, evolution, and dynamics of the Earth and, by extension, other planets. The practical objectives are to:

• Address the most important and difficult problems that have defied solution thus far by fostering collaborations that can fully utilize existing knowledge and technology.
• Contribute a seed-bed for ideas within an integrative conceptual framework that will identify the next generation of critical experiments and observations, and build support and appreciation for them.
• Provide an effective mechanism for cross-disciplinary education of scientists at all career levels.

SCIENTIFIC MOTIVATION

It has been more than 40 years since the wide-spread 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 the plate motions. There are still vigorous debates about the proportion of heat coming from the core versus internal radiogenic heating in the mantle; about the degree to which the mantle is chemically, rheologically and/or viscously stratified and whether there is layered or whole mantle circulation; about the origin and even the existence of mantle thermal plumes rising beneath hot spot volcanic centers like Hawaii and Iceland; the chemical/thermal nature and origin of heterogeneity in the deepest mantle (figure 1); the nature and importance of mechanical coupling between the mantle and the core; the chemical composition of the core and its evolution; and the nature and importance of chemical coupling between the deep Earth and surface reservoirs, especially of water and CO2. Ultimately, fundamental understanding of the Earth's evolution and present dynamics is necessary to better address key issues of societal relevance: (1) natural hazards such as earthquakes and volcanic eruptions; (2) the whole-Earth budget of volatile elements, especially water and carbon dioxide; (3) the impact of internal dynamical processes on climate.

Figure 1. Cartoons representing different end member models for the location of chemical reservoirs in the mantle and their relationship to dynamics. Blue: oceanic plates/slabs. Red: hot plumes. Purple: "primitive" mantle.DMM: Depleted Mantle; ERC: enriched Recyled Crust. (A) Typical geochemical model layered at 660 km depth. (B) Homogeneous mantle except for some mixture of ERC and primitive material at the base. (C) Primitive blob model with added ERC layer; (D) Complete recycling model. (E) Primitive piles model. (F) Deep Primitive layer. From Tackley (2000).

Geological activity is characterized by the movement of materials and heat on scales ranging from regional to global. Indeed, convection of the mantle and core, the action of thermal plumes, movement of tectonic plates at the surface, and infiltration of magma and other fluids at depth offer dramatic examples of Earth's ongoing geological evolution. The geological record provides an integrated history of our planet's mass and heat fluxes. Through seismological, geodetic, heat-flow and magnetic observations, geophysics yields information about the current dynamics of the interior; paleomagnetic and the geo- chemical signatures of magma source regions and of direct samples (xenolith rocks and very deep diamonds brought up in volcanic eruptions) from the interior provide a means of tracking the time scales of these internal processes. A new source of deep materials (>300 km) recently recognized in ophiolites (ancient remnants of oceanic crust) offers a new window into the deep mantle with unknown implications. Combining information about the properties of Earth materials, as derived from petrology and mineral physics, the full range of geological, geophysical and geochemical observations are interpreted through geodynamical models.

Tracking of mass and energy (heat) fluxes lies at the heart of understanding how our planet has evolved over geological time. What is the differential motion of fluids at depth, leading to volcanism and metamorphism due to upward migration toward the surface? What is the potential for downward sequestration of hydrous (and other volatile-bearing) fluids, or even of dense oxide or metallic melts in the deep interior? How effectively is heat transmitted across the core and through the thickness of the mantle, providing the energy that sustains the geomagnetic field as well as the plate-tectonic processes observed at the Earth's surface? The types of problems that arise in deep Earth research are challenging to solve for several reasons: Extreme P-T conditions, impure materials, and complex systems with many interacting factors operating over many orders of magnitude space- and time-scales. Remote-sensing of structures, processes and compositions at great depth with no direct sampling requires sophisticated theories, geophysical inferences, inverse theory, and intensive computational modeling capabilities. Progress requires broad knowledge of multiple fields, more than any one expert can encompass. Individual fields tend to operate on their own, not always recognizing the need for communication across disciplines and often hampered by the lack of a common language. Intrinsic complexity of the internal systems and the constraints on our observations push the limits of both knowledge and technology.Meanwhile, a new generation of disciplinary tools, that will provide unprecedented views of the Earth's interior, is becoming available to the geoscience community, through major infrastructure efforts that are currently under way, or in the planning stages. For example,Earthscope, and more specifically the USArray program provides seismologists with a high resolution "window" into the deep mantle and core with broadband seismic waveform data over the North American continent from densely spaced receivers. The COMPRESprogram allows mineral physicists to perform advanced high pressure and temperature measurements on mineral properties at conditions relevant to the Earth's deep interior and compare them with results of "first principles" calculations and provides an avenue for interactions with material science communities. Other initiatives aim at providing geodynamicists and seismologists with a unified, state of the art framework for mantle and core convection and seismic wave propagation computations (CIG), and researchers in geodesy and geomagnetism with satellite observations that are revolutionizing these fields (e.g. Oersted, Champ, GRACE and Swarm). Paleomagnetic data are being assembled into the MagIC PMAG database. In geochemistry, the enormous volumes of high quality chemical and isotopic data gathered over the past 25 years are now assembled into systematic and broadly accessible databases (GEOROC and PETDB, and ever-improving measurement techniques are providing new perspectives on mantle processes at scales from micrometers to thousands of kilometers. In general, our community has been building "big-science" data gathering tools but using only "small-science" approaches to deep Earth data interpretation. As a result, only partial return on these investments can be expected. In other fields of science, such as Astronomy and Atmospheric Sciences, this issue has been appreciated and addressed.

Given the enormous amount and diversity of observations becoming available, a quantum 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, and define how best to address them by fully utilizing complementary disciplinary data (seismology, geodesy, geo- and paleo-magnetism, measurements of material properties at high pressure and temperature, geochemistry) and modeling tools (seismic wave propagation, convection simulations, ab initio mineral physics computations).

TOWARDS CIDER-II

Accomplishments during CIDER-I

During the last 5 years, with support from the CSEDI program of NSF/EAR and infrastructure support from the Kavli Institute of Theoretical Physics (KITP, Santa Barbara, CA), CIDER held 3 successive summer programs at the KITP. These programs varied in length (4 weeks in 2004, 3 weeks in 2006, 7 weeks in 2008), and each of them was focused on a particular interdisciplinary theme. Each program was organized around a two week "tutorial program" followed by 1 or two weeks of "workshop", intended for ~35 advanced graduate students and post-docs representing a balanced multi-disciplinary range of expertise. The tutorial program featured lectures and hands on practical exercises, led by 9-15 distinguished members of the academic community, introducing the students to state-of-the art disciplinary approaches and tools, and discussing timely research problems whose solutions require a multi-disciplinary approach. During the second week of the tutorial program, several (4-6) multi-disciplinary research topics were identified, and teams were formed comprising a group of students and one or several senior participants. The last week or two was devoted to reading, discussion and identification of ways to address the particular topic within each team. The work accomplished during this "workshop" part of the CIDER program typically led to presentations at AGU, submissions of collaborative proposals to the NSF/CSEDI program, as well as publications.

In the summer of 2008, the first 3 weeks of the summer program represented an experiment in informal interactions between more senior researchers (mostly assistant professor level and above) following the KITP philosophy. The program was held in parallel with the last part of a longer KITP-organized program on "Dynamos", which resulted in fruitful interactions between participants in the two programs.

Building on the success of the previous 3 programs, a 6 weeks CIDER summer program was held in 2010, on the subject of "Fluids and volatiles in the earth's mantle and core". The first 2 weeks of the program consisted informal interactions, occurring concurrently with a KITP program on "The physics of glasses". The two programs are purposely being coordinated to try and maximize the potential benefit of interactions between the two communities of researchers, which will be facilitated by the participation from the geoscience community of mineral physicists.The next 3 weeks featured a lecture/tutorial program for advanced graduate students and post-docs.

The summer 2010 CIDER program at KITP was followed by the 2010 SEDI International Conference, which was held on the U. C. Santa Barbara Campus from July 18th to July 23rd, 2010.

A CIDER community workshop was recently held at the Marconi Center (CA) (May 17-20, 2009), to review the lessons learned from the 3 previous successful CIDER programs and discuss the vision for the next 5 years (CIDER-II).

Advancing outstanding research

In order to achieve progress on the cutting-edge topic of mantle and core dynamics, an integrative framework is necessary. Thermal and chemical heterogeneities are now recognized to play essential roles, with evidence for massive chemical reservoirs in the deep Earth, stagnation of sinking chemically distinct slabs, possible upper mantle/lower mantle differences in bulk chemistry, core convection transitioning from thermal to chemical driving forces upon inner core nucleation, among others.

The following are examples of fundamental across-disciplinary themes that have or should be considered: How to relate seismological and geochemical heterogeneity in the earth's mantle? The mantle transition zone: its structure, composition, dynamics The nature and role of boundary layers in the earth: from the lithosphere/asthenosphere boundary, through the 670 km discontinuity, the core-mantle boundary and the inner core boundary. The distribution of water and volatiles in the earth and their role in plate tectonics. The deep Earth's role in carbon fluidization and sequestration.

Proposed activities for CIDER-II

Expanding from the already established bi-annual summer program, CIDER-II plans are to include the following activities:

• Hold the summer programs annually, with the goal of expanding CIDER to a larger community, including surface and near-surface dynamics. Provide support for participating faculty instructors, graduate students/postdocs.
• Facilitate the activities of research teams formed during the summer programs, to allow full development of new research directions. Provide support for follow?up work on summer program products or activities spawned by working group recommendations through a mechanism of mini-grants to allow graduate students and post-docs to spend up to 3 months at another institution.
• Support working groups to address key topics relevant to CIDER goals, such as developing consensus reports on pressure standards, comparison of aspherical seismic model predictions, comparison of deep structure migration results, production of a priori mineral?physics based elasticity models, development of a new 3D Earth model, assessment of Chondritic Earth Model framework, etc. This could be transformative for our research; there is currently no mechanism forcommunity evaluation, validation, problem reconciliation, or consensus building. This would be a major new activity in Earth Sciences, and could, in particular, guide the EarthScope research program integrative effort.
• Develop and sustain a virtual organization, including the management of debate forums on controversial topics of interest to the solid earth community.

Governance

CIDER-II would rely on a CIDER National Office, hosted by one institution (initially at UC Berkeley) for 5 years, with Director/Associate Director and support staff stipends (1/2 and/or full-time buy outs). Supported by Steering Committee and Advisory Committee structures, the CIDER National Office would manage mini?grant resources, coordinate Disciplinary and Interdisciplinary working groups, sustain the summer graduate training program and thematic workshop, and do the necessary public outreach and organizational functions of CIDER-II.

We welcome your comments, feedback and ideas on future CIDER-II activities. Please send them to earth@seismo.berkeley.edu

This page last modified 11:55, 4 March 2012 (PST)

For questions about this site, contact Professor Barbara Romanowicz(earth@seismo.berkeley.edu)