Staff Directory > Guy Wöppelmann

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Professor in Earth Sciences
University of La Rochelle
Associated scientific institute at CNRS: INSU

Key words : Vertical land motion, GPS methods, sea level change, tide gauges
CV & Publications

Research interests

 

  • vertical displacements of the Earth’s surface at the coast using space geodetic methods (GPS, InSAR...);
  • sea level change over the past decades to century timescales;
  • data archeology: rescue, digitization and quality control of historical sea level records;
  • detection of spatial fingerprints of contemporary land ice melting in sea level records by combining in situ and satellite data;
  • performances of modern tide gauge technologies (acoustic, radar);
  • unification of vertical references, in particular chart datums.

An example of tide gauge and GPS data combination:

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The figure on the right (click on the image to enlarge) shows how well can work corrections of tide gauge records using GPS velocities obtained from a state-of-the-art data analysis strategy. The left panels display annual mean sea levels from high-quality tide gauge records in three different regions of the world coasts (data available at the PSMSL international service). The right pannels show these records corrected for vertical land motion using GPS velocities from our latest solution of the ULR consortium. The spread observed in the rates of sea level change in the left panels is substantially reduced in the three regions (standar deviation of 0.3 mm/year). These results are updated from Wöppelmann et al. (2009) in Geophysical Research Letters.

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In the illustration on the left (click on the image) are represented the principal elements of the observational situation at a tide gauge. Satellite radar altimetry plays an increasing important role in sea level observation. However, to be useful for coastal studies on impacts (submersion, erosion, civil engineering, etc), its data requires a correction in order to transform the satellite geocentric sea levels into relative sea levels with respect to the land. High-precision GPS methods, for instance, can provide this supplementary data such as S = N - U (notations from the illustration) in the idealized case study depicted in the illustration. The situation can indeed be more complex, in particular because here is assumed that the tide gauge and the satellite are observing the same sea levels at the coast and offshore, respectively.



Publications representative of my recent research activities:

(Complete personal bibliography)

Some articles for a large audience & Contribution to books:

  • Wöppelmann G. & M. Marcos, 2015. Le paradoxe de l’élévation du niveau des mers au XXe siècle. Revue XYZ, 143, 29-36.
  • André G., B. Martin Miguez, V. Ballu, L. Testut, G. Wöppelmann, P. Tiphaneau, 2014. La mesure du niveau de la mer par bouées GPS : l’expérience multi-capteurs de l’île d’Aix. Revue XYZ, 140, 25-32.
  • Wöppelmann G. & X. Bertin, 2013. Elévation du niveau de la mer. In Le développement durable à découvert, A. Euzen, L. Eymard, F. Gaill (Eds.), CNRS Editions.
  • Bureau des longitudes (2009). Les Observatoires. Observer la Terre. Ed. Hermann, 309 pp., ISBN 978-27056-6946-1.
  • Wöppelmann G. & P. Pirazzoli, 2005. Tide gauges. In Encyclopedia of Coastal Science, M. Schwartz (Ed.), Springer Netherlands, pp. 985-986, ISBN 1402019033.

Scientific and administrative responsibilities (current) :

  • since 2007: Member of the IAPSO Commission on Mean sea level and tides (IAPSO: International Association for the Physical Sciences of the Oceans);
  • since 2011: Director of the GNSS at tide gauge data assembly center of the GLOSS program of the IOC/UNESCO, hosted at SONEL;
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  • since 2011: Member of the International GNSS Service (IGS) tide gauge (TIGA) working group;
  • since 2012: Chair of the science steering group of the GLOSS program above mentioned;
  • since 2012: Director of the Geosciences speciality of the Master of Sciences for the Environment (SPE) at University of La Rochelle;
  • since 2013: Convenor or co-convenor of a sea level session at the European Geosciences Union (EGU) General Assembly;
  • since 2015: Member of the CNES (French space agency) committee for the Solid Earth area (TOSCA).


Ph-D. Thesis Supervisions
  • Poitevin C. (2015 - in process). Mouvements verticaux du sol le long de la côte par combinaison de données d’interférométrie d’images radar satellites avec des stations permanentes GPS au sol. Application à la côte et confrontation aux observations de niveau marin.
  • Sakic P. (2013 - in process). Simulation de l’apport de données de géodésie off-shore à la sismique liée à la subduction dans l’arc des petites Antilles.
  • Gouriou T. (2007- 2012). Evolution des composantes du niveau marin à partir d’observations de marégraphie effectuées depuis la fin du 18e siècle en Charente-Maritime. Thèse de doctorat de l’université de la Rochelle, soutenue le 26 mars 2012.
  • Santamaria-Gomez A. (2007-2010). Estimation des mouvements verticaux de l’écorce terrestre par GPS dans un repère géocentrique, dans le cadre du projet TIGA. Thèse de doctorat de l’Observatoire de Paris, soutenue le 11 octobre 2010.
  • Letetrel C. (2006-2010). Mouvements verticaux à la surface de la Terre par altimétrie radar embarquée sur satellite, marégraphie, et GPS. Thèse de doctorat de l’université de la Rochelle, soutenue le 25 août 2010.
  • Pouvreau N. (2004-2008). Trois cents ans de mesures marégraphiques en France : outils, méthodes et tendances des composantes du niveau de la mer au port de Brest. Thèse de doctorat de l’université de la Rochelle, soutenue le 26 septembre 2008.