Publication Date:
2017-04-04
Description:
Seismic surface waves with periods of 15 to 20 s are reflected laterally at the northern Apennines. For earthquakes originated and
recorded in the wider Alpine area, a few hundred kilometres north of the Apennines, we can directly observe late arrivals of reflected
regional surface waves. These have a characteristic polarization of particle motion and often dominate the intermediate-period surface
wave coda. Love waves are the most prominent coda arrivals, while reflected Rayleigh waves show smaller amplitudes, and become
clear only after rotation of the recordings to the reflection incidence direction. We can track the development of the Love wave
reflection along a temporary broad-band transect across the northern Apennines, indicating the location of the reflector near to the
highest topography. From spectral element simulations of three-dimensional wave propagation, we attribute the reflection to a
continuous, !270 km long offset in the crust-mantle boundary under the mountain belt with vertical throw of !20 km, thus
supporting a deep crustal root under the outer side of the Apennines fold and thrust belt, and significant crustal thinning on the inner
side. Amplitude reflection coefficients for near-normal incidence can be estimated as !7% for both Love and Rayleigh waves.
Description:
EC Marie-Curie Research Training Network SPICE
(MRTN-CT-2003-504267)
Description:
Published
Description:
149–158
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
reserved
Keywords:
seismogram coda
;
surface waves
;
multipathing
;
3d waveform modelling
;
deep crustal structure
;
04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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