Thread: IRIS WEBINAR - Causes and Consequences of Upper-Mantle Seismic Anisotropy - 4/8, 12 PM Eastern

Started: 2015-04-03 15:42:24
Last activity: 2015-04-03 15:42:24
Topics: Early Careers
Please register for "*Advancing our understanding of the causes and
consequences of upper-mantle seismic anisotropy*" on April 8, 12:00 PM
EDT at

*Presenter:* Lars Hansen, Associate Professor, University of Oxford

*Abstract:* Over the past 50 years, observed anisotropy in seismic wave
propagation has been linked to viscous flow in Earth's upper mantle. The
generally straightforward correlation of seismically fast directions
with the flow direction has been borne out through laboratory and field
observations of crystallographic-preferred orientations (i.e., textures)
in olivine-rich rocks. Thus, a relationship has been established between
the micromechanical deformation of olivine and patterns of seismic
anisotropy. However, as laboratory methods and characterization
techniques have improved, new insight has been gained into the details
of olivine textural evolution, which may allow for new geodynamic
hypotheses to be tested with observations of seismic anisotropy. Here I
will review recent advances in our understanding of olivine textural
evolution. New laboratory experiments reveal a protracted evolution rich
with detail in terms of the symmetry and strength of the resulting
anisotropy. These data have been used to calibrate models for texture
development and mechanical anisotropy that can be used to quantify the
geodynamic consequences of upper mantle anisotropy. I will outline
several applications of these calibrated models to interpreting
seismological observations and predicting geodynamic responses.

After registering, you will receive a confirmation email containing
information on how to attend. *Please note that the webinar software
limits attendance to 100 participants*; join the webinar early in case
it is oversubscribed. Recordings are typically posted shortly afterwards

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