ESP GUEST SEMINAR - Wednesday, 12 February

[Earth System Physics Section]

Earth System Physics
SPECIAL GUEST SEMINAR
Wednesday, 12 February, 11:00 am
Euler Lecture Hall, ICTP Leonardo Building

Giampiero Iaffaldano
University of Copenhagen

Constraints on Earth's rheology from post-glacial rebound analyses can 
help mitigate seismic risk


Earth’s asthenosphere (the 100-200 km thick shell underlying the 
lithosphere) plays a major role in controlling how the motions of 
tectonic plates evolve through time. However, uncertainties in the 
asthenosphere geometrical and rheological properties (i.e., its 
thickness and viscosity) have in the past hampered our ability to make 
inferences on the forces controlling plate-motion changes, and thus on 
the geological processes ultimately responsible for them. Recent 
constraints on asthenospheric properties drawn from global analyses of 
post-glacial rebound data alleviate this problem, but the observations 
on which they rely span time periods in the order of 10^3 years that are 
significantly shorter than the typical time-scales of plate-motion 
changes (10^5 to 10^6 yr). I will initially bring evidence suggesting 
that the properties of Earth’s asthenosphere inferred from post-glacial 
rebound (i.e., over 10^3 yr) remarkably apply also to the more sluggish 
plate dynamics (i.e., over 10^6 to 10^7 yr). I will then show how this 
inference offers new opportunities for the use of plates and microplates 
dynamics in order to assess the hazard associated with earthquake-prone 
crustal faults.