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<p class="MsoNormal" style="text-align:justify"><span
style="mso-ansi-language: EN-US">Dear colleagues,</span></p>
<span style="mso-ansi-language: EN-US">We would like to draw your
attention to the <b style="mso-bidi-font-weight:normal">28th IUGG
General Assembly</b>, <b style="mso-bidi-font-weight:normal">11-20
July 2023, Berlin</b> and our session </span><span
style="mso-ansi-language: EN-US"><span style="mso-ansi-language:
EN-US"><b style="mso-bidi-font-weight:normal">S18 </b></span>titled<b
style="mso-bidi-font-weight:normal"> “Integrating Seismic
Tomography with Mineral Physics and Potential Fields to Describe
the Crust and Upper Mantle Physical State”</b>.</span>
<p class="MsoNormal" style="text-align:justify"><span
style="mso-ansi-language: EN-US">We welcome your contributions
that discuss advances, challenges, and applications in the
interpretation of seismic tomography by using seismology
independent observations to understand the dynamics of the
lithosphere (details below). </span></p>
<p class="MsoNormal" style="text-align:justify"><span
style="mso-ansi-language: EN-US">The <b
style="mso-bidi-font-weight:normal">abstract submission
deadline is 14 February, 2023</b>. For more information,
please visit </span><span lang="EN-GB"><a href="https://protect-au.mimecast.com/s/VTJ4Cr81nytAvA269C7mhTC?domain=iugg2023berlin.org/"><span
style="mso-ansi-language:EN-US" lang="EN-US">https://www.iugg2023berlin.org/abstract-submission/</span></a></span><span
style="mso-ansi-language:EN-US">. </span></p>
<p class="MsoNormal" style="text-align:justify"><span
style="mso-ansi-language: EN-US">Best wishes from the conveners<br>
</span></p>
<p class="MsoNormal" style="text-align:justify"><span
style="mso-ansi-language:EN-US">Judith Bott, Ajay Kumar,
Magdalena Scheck-Wenderoth, Ulrich <span
style="color:black;mso-themecolor:text1">Achauer</span></span></p>
<p class="MsoNormal" style="text-align:justify"><span
style="mso-ansi-language: EN-US">---------------</span><b><span
style="mso-ansi-language: EN-US"><br>
</span></b></p>
<p class="MsoNormal" style="text-align:justify"><i><span
style="mso-ansi-language: EN-US">Session description </span></i></p>
<p class="MsoNormal" style="text-align:justify"><i><span
style="mso-bidi-font-style: normal"><span
style="mso-ansi-language:EN-US">To understand plate
tectonics as driven by mantle thermodynamics and
gravitational forces at interplay with rock rheology, we
need comprehensive images of the in-situ physical properties
(density, viscosity) and underlying state conditions
(pressure, temperature) of the lithospheric plate and its
transition into the upper mantle. Once the present-day
physical state of such a system is defined, the intrinsic
deviatoric stress field and the mantle sources of heat
contributing to active plate deformation can be calculated.
One key insight into the crust and upper mantle physical
state is provided by seismology, namely tomography imaging
of seismic velocity perturbations. Their interpretation in
terms of composition and temperature conditions, however, is
highly non-unique. Despite an ever-growing amount of
laboratory-derived relationships between the seismic
velocity of mantle minerals and their pressure and
temperature derivatives of density and elastic constants,
inversion of seismological information for in-situ bulk rock
temperature is an ill-posed problem. In addition, effects of
anelasticity, e.g., frequency-dependent wave velocity, grain
size and fluid content, are important, but less well
explored. To reduce the number of potential solutions,
additional independent information on crustal configuration
and mantle composition, temperature, pressure and density
can help. As alternative to thermodynamics-based inversions,
empirical approaches to calculate mantle temperature from
seismic tomography models implicitly assume some fixed
mantle composition or calibrate tomography models with
respect to thermal models of the lithosphere and/or
pressure-temperature estimates from mantle xenoliths. With
this session, we intend to resume an open discussion on how
to best exploit mantle seismic velocity models to derive
conclusions on the composition and pressure-temperature
conditions within the upper (including lithospheric) mantle.
We invite contributions integrating multidisciplinary data
on the crust and mantle (geological, seismic, heat flow,
potential fields, xenoliths) with tomographic models to
identify rheological variability exerting the most
significant impacts on crustal and surface deformation.</span></span></i></p>
<p></p>
<pre class="moz-signature" cols="72">--
Dr. Ajay Kumar
Section 4.5, Basin Modelling
Phone: +49 (0)331/2882828
Fax: +49 (0)331/2882828
Email: <a class="moz-txt-link-abbreviated" href="mailto:kumar@gfz-potsdam.de">kumar@gfz-potsdam.de</a>
___________________________________
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
Foundation under public law of the federal state
of Brandenburg
Telegrafenberg, D-14473 Potsdam</pre>
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