A large number of earthquakes have been modelled in detail using seismological, geological and u
z4P
geodetic information. Several common traits have been found for earthquakes kinematics at m:)v>v u
periods longer than 3s. At these frequencies, all large earthquakes (M>7) appear complex with M{3He)&
highly variable slip, and propagate with rupture velocities close to about 80 % of the shear wave ,g 6w2y7 ]
speed. Starting from these kinematic inversions, it is possible to use numerical wave propagation ^4_. 5~(
models in order to estimate the complete radiated field including near and far field effects. /b@8#p x
Radiation can be separated into two main components: a near field term responsible for the socalled j1Q G-Rs&
fling steps due to permanent, geodetic offsets; and the far field that produces pulse like ;6U=fBp7<
motions. Using seismological scaling relations it is possible to explain the main features of yFH)PQ_
displacement spectra using classical seismological models at long periods. Seismic simulations K82pWpR
may now be extended to the frequencies up to a few Hz by means of dynamic rupture propagation, &#w]
2~ |
where rupture is simulated starting from the kinematic models. In this talk I will review the main e%U0^! 8
results obtained so far and the new avenues of research that have been opened thanks to new near O9dIob u4
field earthquake data and the ability to simulate increasingly complex and realistic seismic vtv|H
ruptures in a computer.
