Estimation of seismic and elastic properties of the crust and upper
mantle beneath the Korean Peninsula
Abstract
It is important to perform the quantitative interpretation of the
continental margin lithosphere for a more accurate and comprehensive
understanding of its tectonic behavior. In this study, we derived the
seismic and elastic properties from the 2D seismic data recorded by the
Korea Meteorological Administration (KMA) in 2014. In general, most of
the previous researches have been based on travel time tomography or
Full Waveform Inversion (FWI) methods. However, these methods are not
robust to directly apply to the seismic ambient noise data due to its
low signal-to-noise ratio (SNR). Therefore, we conducted L2-norm
model-based impedance inversion to not only delineate the local
geological structures but also suppress the meaningless footprints in
the observed data. Moreover, we used FWEA18 models (Tao et al., 2018) as
initial velocity and density models to create the inversion result more
stable and accurate. Then, we interpreted the lithosphere and
asthenosphere from the inverted P-impedance model, which is more obvious
than the interpretation of the pre-existing data. The average depths of
Moho and Lithosphere-Asthenosphere-Boundary (LAB) are 30 km and 80km,
respectively. Furthermore, we estimated the change of bulk density as
well as P- and S-wave velocities of the crust, lithospheric mantle, and
asthenospheric mantle. Also, we predicted four elastic properties of
each layer from the inverted seismic properties, such as bulk modulus,
shear modulus, Young’s modulus, and Poisson’s ratio. These model results
can help to understand the physical state and elastic behavior
variations of the lithospheric and asthenospheric mantle as well as
local lithospheric structures beneath the peninsula.