Please see below for sessions of interest to the GeoPRISMS Community, taking place at the 2015 EGU General Assembly in Vienna, Austria (12-17 April) and the 2015 SSA Meeting in Pasadena, California (21-23 April)
EGU Abstract deadline is January 7, 2015, 13:00 Central European Time
SSA Abstract deadline is January 9, 2015, 5 PM PST
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TS5.1/GD5.5. The evolution and architecture of rifts and rifted passive margins: observations and modelling (co-organized)
The formation of rifted continental margins by extension of continental lithosphere leading to seafloor spreading is a complex and still poorly understood component of the plate tectonic cycle. New observations and modelling allow us to investigate the underlying processes. Key questions that need to be resolved include 1) factors that control the geometry and crustal architecture or rifted margins, 2) the role of strain localisation and strain partitioning throughout the rift history, 3) processes responsible for anomalous vertical motions during basin evolution such as phase changes or small scale convective instability of the mantle lithosphere, 4) fundamental controls on the magmatic or a-magmatic nature of rifts and passive margins, 5) interaction between surface processes, tectonics, and climate during rift-passive margin evolution. We encourage abstracts that offer new insights into crustal and lithospheric architecture and processes underlying rifting and passive margin formation as well as smaller scale studies of individual sedimentary basins, using constraints from observations and modelling.
Convenors: Ritske S. Huismans, Delphine Rouby, Magdalena Scheck-Wenderoth, Sylvie Leroy, Jan Inge Faleide
Link to the session: http://meetingorganizer.copernicus.org/EGU2015/session/17510
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TS4.2/EMRP4.10/SM2.2. Mechanical Heterogeneity And Its Transient Evolution Along Fault Zones
Geophysical studies of recent well-monitored mega-earthquakes are able to reveal, with increasing resolution, the complex mechanical heterogeneities along faults (differential locking behavior, differential rupture behavior, rheological and structural variations, among others). Furthermore, observations of various transient events (afterslip, slow slip, tectonic tremors, low frequency earthquakes, viscoelastic relaxation) also evidence the temporal evolution of fault systems. While fault heterogeneities seem to have first order controls on the pattern of strain accumulation/release and carry fundamental information about the mechanical setting of faults, we have limited physical and mechanical understanding of what causes these heterogeneities, their kinematics and transient evolution between major events, and how they ultimately influence the largest seismic events.
We aim to integrate studies from various disciplines in order to compare different observations and provide insights into the physical and transient properties of fault heterogeneities and their relation to earthquakes.
Contributions from geologists, seismologists, geodesists, experimentalists, and modellers are invited, especially studies from recent great earthquakes.
Some suggested topics are:
Roughness/asperities/geometry of faults
Geodetic records of fault slip in different periods of the earthquake cycle
Co-seismic slip inferred from seismic records of various frequencies
Spatiotemporal variation of seismicity and transient events, seismic vs. aseismic slip
Seismic and electromagnetic attributes around faults from tomography
Relation between fault heterogeneity and rock physical/rheological properties
Numerical modelling of fault zone kinematics
Conveners: Marcos Moreno, Hiroki Sone, Stephen Hicks
Link to session: http://meetingorganizer.copernicus.org/EGU2015/session/17509
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TS6.5/GMPV4.7. Crustal construction processes from the Backarc-Arc to the Forearc and the origin of ophiolites of belts and subduction arcs.
This session aims at gathering 4 different communities that work on related problems but that typically do not share discussions.
We would like to gather the communities working on:
1) Ophiolites in Alpine-Himalayan settings.
2) Ophiolites in subduction-related Pacific arcs.
3) Crustal structure in Back-arc, Arc, and Forearc settings of subduction zones.
4) Crustal structure formed at Mid Ocean Ridges.
DEBATE SCOPE
Based on their tectonic history and chemistry the majority of Alpine-Himalayan Ophiolites are interpreted as formed in a Back-arc to Arc setting, but the origin of some Alpine-Himalayan Ophiolites in a Mid Ocean Ridge setting is also under debate. In contrast, ophiolitic complexes found in Pacific arcs are commonly interpreted as created in Arc to Forearc settings, and often related to subduction initiation processes.
It is important to recall that much of what has been learned from ophiolite field studies in the last ~50 years has been widely used to interpret the structure of the oceanic lithosphere flooring most of today’s oceans, and that was formed at oceanic spreading centers, mainly at Mid Ocean Ridges, where in fact most ophioltes may not have been formed.
Interestingly, the comparatively abundant studies of the crustal structure formed at Mid Ocean Ridge have been rarely compared to observations of Back-arc, Arc, and Forearc settings, where most ophiolites were arguably created.
We would like to incite an across-communities discussion of those and related open topics, and encourage contributions that study processes of mountain building (e.g. Alpine-Himalayan) and/or subduction at arcs (e.g. Pacific arcs) and relate them to models of ophiolite formation. In addition we encourage presentations that study active processes of oceanic lithosphere creation in Back-arc, Arc, and Forearc systems of subduction zones, as well as crustal accretion at Mid Ocean Ridges before obduction and relate/compare them to the structure of ophiolites. We also welcome contributions that debate on oceanic lithosphere creation and/or ophiolite formation on any scope, time and space scale that contribute to the currently little explored debate on the contrasting views of the different communities.
Conveners: C. R. Ranero, C. Garrido, C. Faccenna, P. Agard.
Link to session: http://meetingorganizer.copernicus.org/EGU2015/session/17652
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TS8.2/EMRP4.4/GD1.2/GM1.7/GMPV7.12/PS9.10/SSS12.17. 200 years of modelling of geological processes
Convener: Vincent Strak
Co-conveners: Joao Duarte, Wouter Schellart, Fabien Graveleau, Filipe Rosas, Susanne Buiter
Analogue and numerical modelling are an essential tool – and possibly the most successful tool – to study the evolution of long-term geological processes. Since the first publication of laboratory experiments by Sir James Hall (1815) to model folds observed in geological strata two centuries ago, modelling has seen major advances and breakthroughs. The emergence of new techniques in the laboratory, the advent of the scaling theory (Hubbert, 1937), and the development of numerical algorithms, codes and fast computers have all contributed to create the discipline of modelling as we know it today. Resulting studies have focused on a large range of geological processes such as mantle convection, subduction, mountain building, rifting, accretionary wedge processes, crustal deformation, interaction between tectonics and surface processes, and volcanic processes. This session aims to present both historical overviews and new studies on geodynamic and tectonic modelling of geological processes from the crustal scale to the planetary scale, providing a unique opportunity to celebrate the 200th anniversary of modelling of geological processes.
Geodynamics sessions:
GD1 – Geodynamics General Sessions
GD1.1.Open Session in Geodynamics (posters only)
GD2 – Crust, Lithosphere, and Asthenosphere: Observations and models
GD2.1/GMPV7.8/SM6.10/TS9.4. Formation and evolution of the ocean plates
GD2.2/GMPV3.4. Geodynamics of continental crust and upper mantle, and the nature of mantle discontinuities
GD2.3/GMPV3.6. Mantle roots of deep seated magmas: origin and evolution of layered mantle lithosphere in different geodynamic setting
GD3 – Mantle Dynamics: Linking deep and shallow processes
GD3.1/EMRP4.16/GMPV3.5/PS9.4/SM6.13. Mantle dynamics in the Earth and other planetary bodies
GD3.2. Lower mantle heterogeneity – linking slab and LLSVP dynamics
GD3.3/TS7.3. Linking plate tectonics and mantle dynamics through the records of lithospheric motions and deformation
GD3.4/GM3.5/SM6.12/TS3.9. Topo-Europe: Linking mantle dynamics and shallow processes
GD4 – Core Dynamics
GD4.1/EMRP4.14/PS9.8. Earth’s core structure and dynamics: observations, models, experiments
GD4.2/EMRP4.15/PS9.9. Boundary control on the geodynamo
GD5 – Plate Tectonics and Geodynamics
GD5.1/EMRP4.17/GMPV7.7. Subduction dynamics from surface to deep mantle
GD5.2/EMRP4.18/SM6.6/TS6.11. Observations and modeling of subduction-driven deformation in the overlying plate and related feedbacks on the subduction process
GD5.3/GMPV7.10/SM6.11/TS6.10. Orogenesis and geodynamics related to the collision of large- and micro-plates
GD5.4/TS5.7. Mantle dynamics, rifting and post-breakup evolution of passive continental margins: Geological and geophysical observations and models with emphasis on the Atlantic Ocean
GD6 – Regional Geodynamics.
GD6.1/SM6.9/TS7.4. The Arctic connection – plate tectonics and mantle dynamics in the North Atlantic, North Pacific and the High Arctic
GD6.2/CR2.5. Geodynamic evolution of the polar regions and interaction with the cryosphere
GD7 – Experimental/Theoretical Studies on Earth Materials Relevant to Geodynamics
GD7.1/EMRP4.19/TS8.10. Long-term rheological behavior of the crust and mantle inferred from observations and models at laboratory and geological time and spatial scales
GD7.2/EMRP4.20/SM5.4. Anisotropy from crust to core: Observations, models and implications
GD7.3/EMRP4.21/TS2.10. Experimental/Theoretical Studies on Earth Materials Relevant to Geodynamics
GD8 – Integrated Geophysical Observations and Modeling in Geodynamics
GD8.1/TS8.9. Recent advances in computational geodynamics
GD8.2/EMRP4.22/GMPV3.7. Compositional geodynamics: The role of phase transitions, partial melting, and metamorphic reactions in mantle convection and plate tectonics
GD8.3/ERE4.5. Geodynamics in service of petroleum and mineral exploration
GD8.4/CR2.6/ERE3.9. Thermal heterogeneity of continental and oceanic lithosphere: from borehole data to regional and global thermal models (PICO Session)
—————– SSA sessions—————–
Session Title: How Reliable Are Reconstructions and Models of Surface-Rupturing Earthquakes?
Historic surface-rupturing earthquakes have demonstrated a potential for complex, discontinuous rupture traces. With this in mind, how well do reconstructions and models of past ruptures from paleoseismology, geomorphologic slip-rate studies, or finite fault models and forecasts of future surface-rupturing earthquakes [e.g. UCERF3 (CA), WGUEP (UT), J-SHIS (Japan)] realistically describe the complexity of surface ruptures? Are earthquake magnitudes and rupture lengths from empirically-based models consistent with individual field-based observations (e.g. timing, displacement) of past events)? This session will highlight advancements in earthquake science that improve our understanding of fault segmentation, rupture dynamics, distributed deformation, along-strike and down-dip fault-slip gradients, and related seismic hazard topics. We welcome abstracts from a wide spectrum of scientists, including paleoseismologic studies of Quaternary-active structures, detailed studies of modern ruptures, and dynamic or simulator models of rupture scenarios. We invite discussion of new, innovative approaches that characterize active structures and earthquakes using field-based techniques, computer modeling, and remote sensing. The goal of this session will be to consider ways to improve the documentation of past earthquakes and to advance our estimates of earthquake probabilities.
Conveners: Scott Bennett (USGS Golden), Kate Scharer (USGS Pasadena), Julian Lozos (Stanford/USGS Menlo Park)
Invited Speakers: James Dolan (USC), Eileen Evans (USGS), Jacqui Gilchrist (UC Riverside)
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Session Title: Slow Earthquakes: Diversity in Fault Motion and Their Implications in Earthquake Dynamics
Earthquake faults show a variety of motion – from slow slip and associated tremor to supershear rupture. Slow earthquakes emerge as a major player in releasing and redistributing stress over much of the seismic cycles. They are observed globally over multiple spatial and temporal scales. A unifying theory connecting this diversity and its implications on the fault dynamics, however, remains elusive. Moreover, the factors (fault properties, rheology, frictional and material heterogeneity etc.) controlling varied fault slip behaviors and their interplay are poorly understood. We invite abstracts that highlight different aspects of this broad spectrum of fault slip including, but not limited to, slow earthquakes and associated phenomena. We are interested in slow earthquakes in all forms and sizes – from episodic tremor and slip in the subduction zones to seismic swarms operating in smaller scales. Studies encompassing multiple styles of fault slip (slow and fast) and their interactions in space and time are encouraged. We solicit new observations and analyses from all tectonic settings using seismology, geodesy, numerical simulations, laboratory and field experiments.
Conveners: Abhijit Ghosh (University of California-Riverside), Christodoulos Kyriakopoulos (University of California-Riverside), Hongfeng Yang (The Chinese University of Hong Kong)