TY  - JOUR
A1  - Lontsi, Agostiny Marrios
A1  - Garcia-Jerez, Antonio
A1  - Camilo Molina-Villegas, Juan
A1  - Jose Sanchez-Sesma, Francisco
A1  - Molkenthin, Christian
A1  - Ohrnberger, Matthias
A1  - Krüger, Frank
A1  - Wang, Rongjiang
A1  - Fah, Donat
T1  - A generalized theory for full microtremor horizontal-to-vertical [H/V(z,f)] spectral ratio interpretation in offshore and onshore environments
JF  - Geophysical journal international
N2  - Advances in the field of seismic interferometry have provided a basic theoretical interpretation to the full spectrum of the microtremor horizontal-to-vertical spectral ratio [H/V(f)]. The interpretation has been applied to ambient seismic noise data recorded both at the surface and at depth. The new algorithm, based on the diffuse wavefield assumption, has been used in inversion schemes to estimate seismic wave velocity profiles that are useful input information for engineering and exploration seismology both for earthquake hazard estimation and to characterize surficial sediments. However, until now, the developed algorithms are only suitable for on land environments with no offshore consideration. Here, the microtremor H/V(z, f) modelling is extended for applications to marine sedimentary environments for a 1-D layered medium. The layer propagator matrix formulation is used for the computation of the required Green’s functions. Therefore, in the presence of a water layer on top, the propagator matrix for the uppermost layer is defined to account for the properties of the water column. As an application example we analyse eight simple canonical layered earth models. Frequencies ranging from 0.2 to 50 Hz are considered as they cover a broad wavelength interval and aid in practice to investigate subsurface structures in the depth range from a few meters to a few hundreds of meters. Results show a marginal variation of 8 per cent at most for the fundamental frequency when a water layer is present. The water layer leads to variations in H/V peak amplitude of up to 50 per cent atop the solid layers.
KW  - Numerical modelling
KW  - Earthquake hazards
KW  - Seismic interferometry
KW  - Site effects
KW  - Theoretical seismology
KW  - Wave propagation
Y1  - 2019
U6  - https://doi.org/10.1093/gji/ggz223
SN  - 0956-540X
SN  - 1365-246X
VL  - 218
IS  - 2
SP  - 1276
EP  - 1297
PB  - Oxford Univ. Press
CY  - Oxford
ER  -