Every year the GeoPRISMS Office compiles a list of AGU Fall Meeting special sessions that are identified as directly supporting the scientific goals of the GeoPRISMS (and MARGINS) Programs or of interest to the GeoPRISMS community. Your session is not listed? Email us at info <at> geoprisms.org and we’ll be happy to include your session to the list.
**FOCUS GROUP T – TECTONOPHYSICS**
T005: Breaking Up is Never Easy: Why Do Some Rifts Fail and Others Succeed?
Session ID: 22413
The breakup of continents is a fundamental process of plate tectonics. However, we have not yet identified the crucial ingredients that permit complete rupture of strong continental lithosphere. Studies of continental breakup are biased towards success¬ stories – rifts that evolve to oceanic spreading. Some extension episodes cease before this point, presumably in the absence of some fundamental process, initial condition(s), or forcing. Investigations of “failed rifts” may help isolate key processes or conditions that enable continental breakup, particularly when compared to successful examples. Outstanding questions include: Does rift success/failure depend on intrinsic or far-field properties? How do pre-existing structure, magma, and volatiles influence rift initiation, continuation, and extinction? Are failed rifts actually “paused rifts” that can later be reactivated? Do analogous mechanical controls apply to extinct seafloor spreading centers? We solicit contributions from diverse geoscience perspectives, including geodesy, geodynamics, geochemistry/petrology, volcanology, structural geology and seismology.
We look forward to seeing you in New Orleans!
Zach Eilon, Natalie Accardo, James Muirhead, Sarah Stamps
T007: Continental Rifts and Passive Margins: Geology, Geophysics, Geodynamics
Session ID#: 22111
This session invites contributions on rifts and rifted margins that integrate new data sets, approaches or viewpoints. Studies can range from the outcrop to the basin or lithospheric plate scale, and include global examples. Innovative concepts and techniques based on field geology, seismology, geodesy, marine geophysics, plate reconstructions, geochemistry, sedimentology, or modeling are encouraged. Topics may include but are not limited to fault dynamics, shear zones, tectono-magmatic and sedimentary processes, impact of volatiles, the continent-ocean transition, influence of mantle dynamics and surface processes, and the role of tectonic inheritance. We particularly encourage submissions that explore along-strike structural and magmatic variations in rifts and passive margins linked to 3D modeling studies. Emphasis will be given to presentations conveying an integrated picture by bridging spatial or temporal scales, or by combining results from active rifts, failed rift arms, passive margins or fossil rifted margins exposed in mountain belts.
Conveners: Sascha Brune (Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences), W Roger Buck (Columbia University of New York, LDEO), Patricia Persaud (Louisiana State University), and Gianreto Manatschal (University of Strasbourg)
T011: Eastern North American Margin: Multidisciplinary Studies
Session ID#: 24298
The Eastern North American Margin (ENAM) records a complex geologic and tectonic history, encompassing two complete Wilson cycles from supercontinent assembly to breakup over the past ~1.3 billion years. It is a natural laboratory to examine the orogenic histories, the lithospheric behavior, and the interaction between crust and upper mantle beneath passive margins, which are fundamental for our understanding of plate tectonics in general. This session invites multidisciplinary contributions from geology, geophysics, tectonics, and geodynamics on the ENAM with new datasets, new methods, new models, and new ideas, with particular interests of the integrated results from multiple disciplines on the study of the 3-D geometry and the tectonic evolutions of this passive margin. Topics may include but are not limited to understanding of the tectonic history of orogenic processes, the crustal and upper mantle structures and dynamics, the nature and origin of magmatic activities and the links to tectonic processes.
Xiaotao Yang (University of Massachusetts Amherst), Cong Li (University of Massachusetts Amherst), Michael L Williams (University of Massachusetts Amherst), Vadim L Levin (Rutgers University)
T013: Exploring the Characteristics and Dynamics of Oceanic Plates Entering Subduction Zones
Session ID#: 24328
Oceanic plates entering subduction zones play a key role in transporting material from Earth’s surface to the deep interior. In the last decade, several marine geophysical studies have revealed new high-resolution observations of bending-induced normal faults and additional structural variations suggesting infiltration of water into the crust and mantle of the downgoing plate. This session aims to highlight these findings as well as examine the relationship between large outer-rise earthquakes, megathrust events, compositional variations in the incoming plate and forearc, and the tectonic forces acting on the downgoing plate and the plate boundary interface. We also welcome presentations based on geophysical and geological studies of incoming oceanic plates, analyses of rock samples, effects of plate bending on the earth’s volatile cycle and igneous activities in the incoming plate, and numerical modeling studies that aim to elucidate the key tectonic processes within the incoming plate.
Conveners: Shuichi Kodaira (JAMSTEC), Douglas Wiens (Washington University in St Louis), Asuka Yamaguchi (University of Tokyo) and John Naliboff (University of California Davis)
T015: Fluid migration through subduction zones: observations and the consequences on geodynamic processes and natural hazards
Session ID#: 25865
Water plays a vital role in the Earth’s evolution. At subduction plate boundaries, vast quantities of fluid are exchanged between the Earth, ocean and atmosphere; however, water transport through subduction zones is only partially understood. Volatile cycling is fundamental to the petrogenesis and eruption of arc magmas. Fluids and dehydration reactions may also play a key role in the earthquake cycle. This session will address some key scientific questions of volatile cycling. What is the role of the slab mantle as a vessel for transporting water into the subduction zone? What are the pathways of volatiles through the subduction system thereby impacting geodynamic processes (e.g. mantle flow)? How are volatile pathways manifested in seismic, volcanic and mineralization potential? We welcome contributions from a range of studies on diverse subduction environments from various disciplines (e.g., but not limited to: geophysical imaging, rock physics, geochemistry, geodynamic modelling).
Conveners: Stephen Paul Hicks (University of Southampton), Lidong Bie (University of Liverpool, Liverpool), Andreas Rietbrock (University of Liverpool)
T016: Geochemical Evolution of Convergent Margins from Asthenosphere to Atmosphere
Session ID#: 21897
Do you have an interest in the climate-tectonic-magmatic-
We invite you to submit an abstract to the topical session “Geochemical Evolution of Convergent Margins from Asthenosphere to Atmosphere” at this year’s AGU Fall Meeting in New Orleans, LA (Dec. 11-15, 2017). We aim to bring together a diverse group of geochemists tackling interdisciplinary questions at modern and ancient convergent margins.
Invited Speakers: Cin-Ty Lee (Rice University) and Carina Hoorn (University of Amsterdam).
The session description is below. We hope to see you in New Orleans!
Kendra Murray, Mauricio Ibañez-Mejia, & Alexander Rohrmann
The importance of links between processes in the mantle, crust, hydrosphere, and atmosphere at convergent margins is increasingly clear, but the mechanisms, timescales, and even directionality of these connections remain poorly understood. These interactions influence the growth, recycling, and destruction of the lithosphere; induce rapid shifts in surface elevation and produce high topography that can affect atmospheric circulation; and drive feedbacks between precipitation, rock deformation, uplift, basin development, landscape evolution, and biologic change. Furthermore, convergent margins generate the planet’s largest earthquakes and modulate greenhouse-gas budgets via volcanism and chemical weathering. In this session, we aim to bridge temporal, spatial, and disciplinary gaps between geochemical studies of Andean-type margins. We invite contributions that place the geochemistry of modern and ancient convergent margins within the context of these interactions. We particularly welcome multi-method approaches that include geochronology, thermochronology, cosmogenic nuclide-dating, stable isotope measurements, leaf-wax lipid-biomarkers, or other biological proxies.
T022: Integrated view of the Gulf of California and adjacent western Mexico and U.S.A. plate boundary: Tectonics, geophysics, structure, volcanology, petrology, stratigraphy and sedimentology, paleontology, geomorphology, geochronology, ore deposits and hydrothermal vents, and marine geology
Session ID#: 25313
The Gulf of California and the surrounding parts of western Mexico, and the Salton Trough and surrounding parts of the USA, form an ideal natural laboratory for studying a very broad spectrum of inter-related geological and geophysical processes. Prior AGU sessions have focused on particular aspects, such as tectonophysics or marine geology, but all of the topics listed in the title for this session can be better understood when considering advances in the other topics listed therein. The new venue for 2017 (New Orleans) can attract a broader spectrum of researchers than those that normally attend AGU. Now is the time to synthesize results in a multi-disciplinary session that will attract workers in all aspects of the geology and geophysics of the Gulf of California/Salton Trough and adjacent western Mexico and U.S. region. We solicit posters from a very broad base, and especially encourage interdisciplinary contributions.
Conveners: Cathy Busby (University of California Davis), Raquel Negrete-Aranda (CICESE National Center for Scientific Research and Higher Education of Mexico), Joann Stock (California Institute of Technology), and Paul Umhoefer (Northern Arizona University)
T028: New Insights On The Cascadia Subduction Zone From Offshore And Amphibious Studies
Session ID#: 24812
Subduction zones, one of Earth’s fundamental tectonic environments, play a key role in many Earth processes. Consequently, they require study by interdisciplinary methods. However, our understanding of subduction zones has been limited by a lack of offshore and amphibious data. At the Cascadia subduction zone, new data collected over the last several years have helped close this gap, elucidating a wide range of new insights, including the structure of the incoming lithosphere, the role of water and volatiles in the subducting plate, asthenospheric flow above and below the subducting lithosphere, the transition from locking to slipping behavior along the plate interface, and the nature of episodic tremor and slip. We invite contributions broadly related to Cascadia geoscience that focus on new results from seismology, magnetotellurics, geodesy, geodynamics, hazards, paleoseismology, geochemisty and petrology, with particular emphasis on insights gained from the contribution of offshore and amphibious data.
Conveners: Helen A Janiszewski (Columbia University of New York), William Bythewood Hawley (University of California Berkeley), Kerry Key (Institute of Geophysics and Planetary Physics La Jolla), and Matthew James Cook, Scripps Institution of Oceanography)
T032. Role of Pre-Existing Structures on Plate Deformation in Continental Rifting and Subduction Zones
Session ID: 27474
This session seeks to discuss the current state of knowledge of plate deformation in continental rifting and subduction zones as affected by the presence of pre-existing structures. Studies have shown how strain is accommodated along pre-existing structures, and how geological hazards are localized where the older structures are present. Other studies have shown how pre-existing structures are not important in the formation of new faults. Understanding the effects of these older structures are important to comprehend seismic hazards, plate kinematics, initiation and evolution of continental rifting, subduction initiation, and strain partitioning in subduction zones. We seek contributions that use geophysical (seismic, geodetic, remote sensing, potential fields), numerical and/or analog modeling, and geological techniques to understand strain accommodation, geologic hazards, subduction processes, deformation history, and plate kinematics, as affected by pre-existing structures. This session also encourages contributions on future research directions on strain accommodation on continental rifting and subduction zones.
Daniel A. Laó-Dávila, Estella A. Atekwana, and Mohamed Abdelsalam
Oklahoma State University
T036: Subduction Dynamics Across the Scales
Session ID#: 25133
Subduction zones display a wide variety of tectonic and earthquake behaviors across a range of timescales. Seismic tomography, laboratory and numerical models have helped to understand plate boundary evolution at the geological time-scale. However many aspects of short-term subduction dynamics remain unclear. The series of thrust megathrust earthquakes of the last 15 years, besides highlighting the social relevance of geodynamic studies, has opened a window into the dynamics of subduction zones at the seismic cycle time-scale. The combination of seismic, geodetic and numerical modeling has helped to understand the physical characteristics of the megathrust earthquakes and the role of the fault geometry, temperature, fluid circulation, petrology and seismic/aseismic energy partitioning to the dynamics convergent margins. We welcome contributions from geodynamicists, seismologists, geodesists and geologists aiming at exploring the relationship between subduction zone dynamics and seismic cycle.
Conveners: Gabriele Morra (University of Louisiana at Lafayette), Emma Hill (Earth Observatory of Singapore), Thorsten W Becker (University of Texas at Austin, Austin), and Ylona van Dinther (ETH Swiss Federal Institute of Technology Zurich)
T037: Subduction Top to Bottom 2, with a Caribbean Flavor
Session ID#: 22904
From top-to-bottom, many geological, geophysical, petrologic/geochemical, and theoretical advances have been made toward understanding subduction zone processes and dynamics since AGU geophysical monograph “Subduction Top to Bottom” was published 20 years ago. This session and a related themed issue in GEOSPHERE are intended to revisit the issues that were explored in the 1996 publication and re-assess them in light of recent advancements as well as explore new discoveries and advances in subduction zone research. We invite the broadest possible range of contributions, including subduction-related hazards (volcanic eruptions, earthquakes and tsunamis) and resources, and we encourage contributions regarding Caribbean subduction.
Conveners: Gray E Bebout (Lehigh University), David W Scholl (USGS Geological Survey, Menlo Park), Robert J Stern (Univ Texas Dallas) and Philippe Agard (University Pierre and Marie Curie Paris VI)
T047: Transform Plate Boundaries: Mechanics and Hazards
Session ID#: 26428
Transform plate boundaries offer a window into the mechanical deformation of lithosphere absent of external mantle processes (corner flow, upwelling). Continental transforms also present significant hazards due to their proximity to population centers. A variety of deformation styles occur at transform plate boundaries, particularly at fault stepovers, endpoints, and in oblique zones. Recent ruptures of transform faults including the Kekerengu Fault of New Zealand and the Queen Charlotte Fault of western North America highlight the need for improved understanding of the mechanics and deformation processes associated with transform systems. We seek contributions highlighting new results from the recent Kaikoura earthquake and studies of the Queen Charlotte Fault, the San Andreas Fault, the North Anatolian Fault, and the Alpine Fault. We emphasize the importance of multi- and cross-disciplinary approaches to study transform systems and welcome broad contributions, especially research involving earthquake seismology, paleoseismology, marine geology and geophysics, tectonic geomorphology, and geodesy.
Conveners: Maureen Walton (USGS Pacific Coastal and Marine Science Center Santa Cruz), Uri ten Brink (USGS Coastal and Marine Science Center Woods Hole), Nathan Miller (USGS Coastal and Marine Science Center Woods Hole), Danny Brothers (USGS Pacific Coastal and Marine Science Center Santa Cruz)
**FOCUS GROUP S – SEISMOLOGY**
S031: Advances in Full Waveform Modeling, Inversion, and Imaging
Session ID#: 25710
Full-waveform modeling has enabled seismologists to accurately account for complex wave propagation in three-dimensional (3D) heterogeneous, anisotropic, and (an)elastic Earth. This has led to great progresses in imaging of the Earth structure and studies of seismic sources. This session provides a forum for developments in full-waveform-based methods and applications, including but not limited to: (1) development and validation of forward modeling techniques and inversion algorithms, (2) automatic full-waveform data processing algorithms, (3) multi-scale imaging of velocity, anisotropy, density, and attenuation structures using earthquake signals, ambient noise, and active-source data, (4) estimation of earthquake source locations, moment tensors, rupture processes, and fault structures, (5) model assessment and validation, (6) full-waveform migration, and (7) wave-prediction and observation of site amplification, surface ground-motion, and seismic hazard. Topics combining full-waveform methods with other geophysical constraints and presentations highlighting new geological/tectonic insights from full-waveform approaches are strongly encouraged.
Conveners: Xueyang Bao (University of Rhode Island), Yang Shen (University of Rhode Island), Nian Wang (University of Rhode Island), and Dmitry Borisov (Princeton University)
S035: Seismically surveying North America: synthesis and emerging ideas as USArray spans Alaska and the CCArray initiative builds momentum
Session ID#: 24626
A systematic broadband seismic survey of an entire continent is a former pipe dream from the seismology community that has recently made major steps toward reality. The EarthScope program’s USArray Transportable Array has successfully covered the contiguous 48 states of the US, and is just reaching its maximum extent in Alaska and northwestern Canada. This session welcomes studies striving to synthesize new insights into continental structure, wave propagation, and seismic sources illuminated by comprehensive coverage of the contiguous US, as well as studies with nascent results and hypotheses from Alaska and northwestern Canada. Coverage of North America remains incomplete and the growing CCArray initiative may offer an opportunity to connect the existing broadband data sets by systematically sampling the Canadian Cordillera. Studies with relevance to the potential science targets, design, and capabilities of the CCArray concept are encouraged.
Conveners: Brandon Schmandt (University of New Mexico), Scott Burdick (University of Maryland College Park), Pascal Audet (University of Ottawa), and Emily Hopper (Brown University)
**FOCUS GROUP OS – OCEAN SCIENCES**
OS008 Geological, Oceanographic, and Biological Processes of the Western Pacific Convergent Margins and Trenches
Session ID#: 22908
The last few years have witnessed major progress by the international community in multi-disciplinary investigations of the western Pacific margins. We sincerely invite your contributions to the following special session that will highlight these major advances and facilitate inter-disciplinary exchanges at the 2017 Fall AGU meeting.
The western Pacific Ocean is dominated by major convergent plate margins and deep trenches, providing a unique natural laboratory to investigate Earth’s lithosphere-ocean-biosphere interaction, from subduction plate mantle dynamics, to deep ocean circulation and mixing, to microorganisms in the hadal extreme environment. The last few years have witnessed major progress by the international community in multi-disciplinary investigations of the Mariana, Izu-Bonin, Japan, and other western Pacific trench systems. This session will highlight these recent advances, promote inter-disciplinary exchanges, and enhance further international collaborations. We welcome contributions from a wide spectrum of research: (1) Geology, geophysics, and geodynamics of the subduction process and convergent plate margins; (2) Petrology and geochemistry of margin volcanism; (3) Physical and chemical oceanography of the deep ocean circulation, mixing, and interaction with mid- and upper ocean layers; (4) Microbiology of the water column and sediments; and (5) Interaction between geological, oceanographic, and biological processes.
Conveners: Jian Lin (Woods Hole Oceanographic Institution), Robert J Stern (Univ Texas Dallas), Yasuhiko Ohara (Hydrographic and Oceanographic Department of Japan), Chuanlun Zhang (Southern University of Science & Technology)
**FOCUS GROUP EP – Earth and Planetary Surface Processes**
EP033: Reconstructing landscape dynamics and environmental signals from stratigraphy and relict landscapes
Session ID#: 29495
Yes, another AGU session: sorry about this, but there’s just so much fun to be had in New Orleans, trust me! OK, if you are a stratigrapher, or a geomorphologist interested in relict landscapes (or somewhere in between), this might be the session for you!
Landscapes are shaped by sediment transport systems with climate, tectonics, and sea-level as their ultimate forcing conditions, and the physical sedimentary record provides a rich archive of past surface processes and their formative environmental conditions. Quantitative estimates of the hydraulic and morphodynamic conditions of systems that are no longer active enhances our understanding of Earth and planetary surface dynamics. Such estimates can also be useful for constraining formative environmental conditions, exploring how terrestrial and marine systems respond to external perturbations, for validating models of long-term sediment-transport dynamics, and for unraveling the history of surface processes on other planets and moons. We invite contributions that explore these thematic issues across a wide range of space and time scales including but not limited to studies focusing on erosional networks, alluvial and fluvial depositional systems, coastal and deltaic settings, and shallow and deep marine environments on Earth or other planets. Contributions from field, experimental, computational, and theoretical studies are all welcome.
We look forward to invited presentations from Angela Hessler and Mackenzie Day.
Kyle Straub, Elizabeth Hajek, Zoltan Sylvester, and Vamsi Ganti
**FOCUS GROUP DI – Study of Earth’s Deep Interior**
DI011: Linking Mantle Dynamics to the Geological Record
Session ID#: 26121
We’d like to bring our AGU 2017 session to your attention: “Linking Mantle Dynamics to the Geological Record”
Our target is to investigate geological constraints and how they might be used to test geodynamic models of mantle convection. This broad session is aimed at bringing together a range of people with backgrounds from across geology, geophysics and geodynamics. All are welcome, and we hope that you might consider entering an abstract in our session.
Confirmed invited speakers:
Mattia Guerri (Dublin institute for Advanced Studies)
Jessica Stanley (GFZ Potsdam)
Conveners: Mark Hoggard (University of Cambridge), Mélanie Gérault (University of Lyon), Sia Ghelichkhan (LMU Munich), Lorenzo Colli (LMU Munich)