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SUMMARY:Whole Earth oscillations: Thé key to imaging Earth’s deep inter
 ior - Arwen Deuss - Utrecht University
DTSTART:20240522T130000Z
DTEND:20240522T140000Z
UID:TALK216229@talks.cam.ac.uk
CONTACT:Lisanne Jagt
DESCRIPTION:Tectonic processes at Earth’s surface\, are driven by convec
 tion deep in Earth’s mantle. Seismic tomography using earthquakes is the
  main tool to directly image the lower mantle. Such images show two large 
 continental size regions just above the core mantle boundary\, one located
  under the Pacific and the other one under Africa. These two regions have 
 low shear wave velocity\, but their role in mantle convection as either a 
 thermal plume or a stable compositional pile is still heavily debated. Her
 e\, I will show that the key to unravelling the nature of these two region
 s are whole Earth oscillations. These normal modes do not only provide she
 ar wave velocity\, but also additional information such as their density a
 nd attenuation. We find that the low velocity regions are partially dense 
 at their base and have weak attenuation\, requiring puzzling new interpret
 ations in terms of mantle dynamics.
LOCATION:Wolfson Lecture Theatre
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