A generalized theory for full microtremor horizontal-to-vertical [H/V(z, f)] spectral ratio interpretation in offshore and onshore environments

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 ne...

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Autores:
Tipo de recurso:
Fecha de publicación:
2019
Institución:
Universidad de Medellín
Repositorio:
Repositorio UDEM
Idioma:
eng
OAI Identifier:
oai:repository.udem.edu.co:11407/5760
Acceso en línea:
http://hdl.handle.net/11407/5760
Palabra clave:
Earthquake hazards
Numerical modelling
Seismic interferometry
Site effects
Theoretical seismology
Wave propagation
Computation theory
Hazards
Interferometry
Marine applications
Matrix algebra
Numerical models
Offshore oil well production
Surficial sediments
Wave propagation
Earthquake hazard
Exploration seismology
Fundamental frequencies
Horizontal-to-vertical spectral ratios
Sedimentary environment
Seismic interferometries
Site effects
Theoretical seismologies
Earthquakes
algorithm
Green function
marine environment
microtremor
numerical model
offshore structure
radar interferometry
seismic hazard
site effect
surficial sediment
theoretical study
wave propagation
Rights
License
http://purl.org/coar/access_right/c_16ec
Description
Summary: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. © The Author(s) 2019.