Sessions of interest at the AGU/CGU Joint Assembly & Japan Geoscience Union 2015

Please see below for sessions of interest to the GeoPRISMS Community, taking place at the AGU/CGU Joint Assembly in Montreal, Canada (3-7 May, 2015) and the Japan Geoscience Union in Makuhari Messe, Japan (24-28 May, 2015)

Joint Assembly abstract deadline is January 14, 2015

Japan Geoscience Union abstract deadline is February 18, 2015

> More information about GeoPRISMS related meetings available online

—————– 2015 AGU/CGU Joint Assembly—————–

Session Title: Understanding slow slip and tectonic tremor process along a variety of deformation boundaries

Conveners: Yajing Liu and Rebecca Harrington

Slow slip phenomena refer to the release of strain energy within a period longer than it typically takes for a dynamic earthquake of the equivalent size. A wide spectrum of slow slip phenomena, including episodic slow slip events, low-frequency earthquakes, afterslip, and transient glacial movement, have been reported along different types of deformation boundaries, but their underlying physical mechanism and potential interaction with dynamic earthquakes remains elusive. In this session we aim to integrate seismic and geodetic observations on direct imaging of the slow slip environment and the transition zone, as well as field, experimental and numerical investigations on the physical mechanism of slow slip phenomena. We invite abstracts focusing on the spatiotemporal evolution of source properties of slow slip observations, and on experimental and theoretical topics that explore possible sources of pressurized fluids and the role they play in the slow slip process.

—————– Japan Geoscience Union 2015—————–

S-CG14. Mixed volatiles in subduction zones; Physical and chemical properties and processes

Principal volatiles in subduction zones and CO2 and H2O derived from devolatilization of carbonate and hydrous minerals in subducted oceanic crust and upper mantle. In the forearc region, highly reduced CH4 may be formed via deserpentinization of forarc mantle. Halogens (F and Cl) are can also be transported at least to upper mantle depth. Fluorine may, in fact, enhance the P-T stability of hydrous minerals.Release of volatiles causes changes in elastic properties of the residual devolatilized rocks, which, in turn, governs seismic velocities, density, shear strength, and compressibility. The intergranular pore fluid also affects these properties. Whether or not fluid forms an interconnected network is critical for these properties. Fluid interconnectivity also controls the extent to which the fluid fluxes melting in and above subducting slabs and the trace and isotopic signatures of the source materials of melting. Physical properties of magma affect style of eruption. These properties, in turn, are affected by H2O/CO2 and F/Cl abundance ratios.

This session will focus on observations, experiments and theory to aid our understanding of

1. Relationship between fluid composition, pressure and temperature and connectivity of intergranular fluid

2. Shear strength and elastic properties of volatile-bearing mineral assemblages

3. Pressure(depth)-temperature and redox-controlled stability of volatile-bearing minerals in subduction zones and beyond

4. Melting phase relations and volatile compositions in subduction zones

5. Seismic activity and its relation to volatiles in minerals and in fluids and in melts

6. Solubility and solution mechanisms of major, mineral, and trace elements in silicate-saturated mixed fluids.

7. Silicate-saturated fluids and volatile-saturated melts and alteration processes in subduction zones.

8. Volatiles and style of volcanic eruption

Please visit URLs:, and, for more information about the meeting, relevant dates, its objectives, history and venue and/or contact us directly.

We truly hope you would want to contribute to this session.

Bjorn O. MYSEN


Dapeng Zhao