Trans-Atlantic imaging of the Lithosphere-Asthenosphere Boundary | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS


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Marine geosciences

  Trans-Atlantic imaging of the Lithosphere-Asthenosphere Boundary

The lithosphere is the main building block of plate tectonic, and Lithosphere-Asthenosphere Boundary (LAB) is most prevalent plate boundary on the Earth. The objectives of the TransAtlanticIlab project are to characterize the nature of the lithosphere from its formation at mid-ocean ridges to up to 75 Ma old crust and image the LAB using a combination of different geophysical methods across the Atlantic Ocean.


The European Research Council (ERC), the main European Union funding body, has awarded an ERC Advanced Grant to Professor Satish Singh, to study the oceanic lithosphere down to its base, at up to 100 km depth. The data were acquired aboard WesternGeco’ IsoMetrix vessel M/V Western Trident during March-April 2015. A total of 2810 km ultra-deep seismic reflection data was acquired starting from Greenwich Meridian at 1º S, at about 75 Ma of oceanic lithosphere in nearly E-W direction, crossing the Mid-Atlantic Ridge at 1.3º S, corresponding to zero age of the lithosphere. The profile extends ~500 km west of the Mid-Atlantic Ridge and transects 0-25 Ma of the oceanic lithosphere on the South American Plate.  


The reflection experiment will be complemented by refraction data acquisition along one part of the profile, providing velocity information that would be useful to migrate these data, and also characterize the velocity structure down to 20-30 km depth. This part of the project will be jointly carried out by GeoMar in Germany and IPGP in France.  Furthermore, 30 broadband seismometer will be deployed along the same profiles in order to charaterise the large scale velocity structure of the upper mantle, and possibly image the LAB using receiver function technique.  The British Natural Environmental Research Council and an ERC grant to Dr. Kate Rychert will fund this part of the project. The National Science Foundation grant to Dr. Steve Constable and Dr. Kerry Key will enable deployment of magnetotelluric instruments along the same profile. All these data will be jointly interpreted to develop a model of the formation and evolution of the oceanic lithosphere.

For more information about the reflection experiment of the TransAtlanticILAB project please follow the link below