Three main themes will be discussed during this workshop:
- Comparing gravity with geometrical space technique (like VLBI, LLR, SLR, DORIS or GNSS) to determine more precisely the surface deformation
Chair: H. Steffen, J. Arnoso
This session will focus on the intercomparison of techniques to monitor and understand various deformation mechanisms of the Earth occurring at different spatial and temporal scales. We can quote for instance post-glacial rebound, present-day ice mass changes, tidal deformation, surficial loading, co- and post-seismic deformation and volcanic deformation. The involved temporal scales range from seconds to years and the spatial scales range from millimeters to continental dimension. Large-scale deformation monitored by space geodetic measurements (e.g. GRACE, GOCE) as well as local deformation monitored by space techniques and gravimeters at a site are encouraged in this session.
Invited speakers:
- Emil Nielsen (DTU Space, Denmark): "Geodynamics and gravity change in Greenland - status and results of absolute gravity measurements collocated with the GNET GNSS stations"
- Joachim Gottsmann (Univ. Bristol, UK): "Volcano deformation in the Central Andes and the Main Ethiopian Rift: Perspective from integrating InSAR, GNSS and gravimetric observations"
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2. Transfer function of the Earth at various time-scales related to the elastic and visco-elastic properties of the Earth
Chair: S. Rosat, Y. Rogister
This session will deal with studies of the gravity-to-height changes ratio in order to discriminate vertical motion from mass transfer. The influence of topography, rheology and lateral heterogeneities of the Earth makes the intercomparison of gravity and height changes more difficult to interpret in terms of Earth’s structure and properties. So this session will help to understand such effects. Studies on Love numbers determination and computation are welcome in this session, as well as rheological constraints from observations.
Invited speakers:
- Giorgio Spada (Urbino, Italy) : "Some theoretical aspects of normal mode theory in linear viscoelastic bodies, with relevance to GIA, tidal, and seismic applications"
- David Al-Attar (Cambridge, UK) :"Work on glacial isostatic adjustment and mantle viscosity, including the application of adjoint methods to the associated inverse problem"
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3. From the modeling of geophysical layers to the realization of a terrestrial reference frame: geocenter motions, modeling accuracy, …
State of the art and next step towards the millimeter accuracy?
Chair: J.-P. Boy, J. Bogusz
Thanks to ever-improving measurement techniques and computation methods, reaching a millimeter or even a sub-millimeter level precision has become the new challenge of the geodetic community. In that purpose, all the processes involved in the quantification of the Earth’s surface deformation must be identified and the associated errors reduced. This session deals with modeling of the surface layers (oceans, atmosphere, continental hydrosphere) that strongly influence the space and ground measurements of surface deformation and the realization of the terrestrial reference frame. Studies on the geocenter motion are encouraged in this session.
Invited speakers:
- Krzysztof Sosnica (Wrocław University of Environmental and Life Sciences, Poland): "Limitations, Challenges, and Prospects of Different Space Geodetic Techniques used for the Determination of the Geocenter Motion"
- Laurent Métivier (IGN/LAREG, France): "Geocenter motions and Earth figure changes as seen by ITRF2014"
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