characterizing basin scale wavefields using a dense ... · characterizing basin scale wavefields...
TRANSCRIPT
![Page 1: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/1.jpg)
CHARACTERIZING BASIN SCALE WAVEFIELDS
USING A DENSE SEISMIC ARRAY
Pierre BOUÉ
Marine DENOLLE
Naoshi HIRATA
Shigeki NAKAGAWA
Greg .C. BEROZA
![Page 2: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/2.jpg)
The Kanto Basin and
the MeSO-net
Tokyo
One year (2012)
of 3-components
continuous data
![Page 3: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/3.jpg)
The Kanto Basin and
the MeSO-net
Tokyo
A (very) good a priori
velocity model
(Koketsu et al., 2009)
![Page 4: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/4.jpg)
Ground Motion in the Kanto Basin
Fururuma &Hayakawa
(2007), M6.6 Niigata-ken
Chuetsu
Koketsu & Kikuchi
(2000), M5.7 offshore
Izu peninsula
Denolle et al. (2014)
Amplification in the basin
as a function of basin
depth (Long period)
From Earthquake Data From Simulations From Ambient Noise
and/or Interferometry
![Page 5: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/5.jpg)
Ground Motion in the Kanto Basin
From Ambient Noise?
• Can we extract more than the
amplification from reconstructed
noise-based Green’s function in
such heterogeneous medium?
• Reconstruction of surface wave
higher-modes? • Savage et al. (2013) in the Canterbury region (NZ)
• Rivet et al. (2015) in the valley of Mexico
• Complex dispersion pattern?
• Basin edge effects?
From Ambient Noise
and/or Interferometry
Denolle et al. (2014)
Amplification in the basin
as a function of basin
depth (Long period)
![Page 6: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/6.jpg)
Averaged Correlation Tensor
Hi-net Only
• Filter [1,10]s
• Rayleigh wave (ZZ,RR,ZR,RZ)
• Love wave (TT)
• Low dispersion (~3 km/s)
![Page 7: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/7.jpg)
Averaged Correlation Tensor
MeSO-net Only
• Filter [1,10]s
• Rayleigh waves (ZZ,RR,ZR,RZ)
• Love waves (TT)
• Strong dispersion between
300 m/s and ~3 km/s
![Page 8: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/8.jpg)
Averaged Correlation Tensor
Observed Dispersion
![Page 9: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/9.jpg)
Averaged Correlation Tensor
Theoretical Dispersion
• Rayleigh waves
• Mode 0,1… and 2?
• Osculation point at ~4.7s
• Love wave
• First 3 modes
![Page 10: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/10.jpg)
Particle Motion Analysis
Prograde Vs Retrograde
• Computed from the eigenfunctions at
the surface
• Identification of the 1st higher mode
Rayleigh wave in the data?
![Page 11: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/11.jpg)
Particle Motion Analysis
Prograde Vs Retrograde
![Page 12: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/12.jpg)
Particle Motion Analysis
Prograde Vs Retrograde
![Page 13: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/13.jpg)
Propagation Across
the Basin
• Example for a radial excitation
• Fundamental and 1st higher mode
• Bending and reflection
![Page 14: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/14.jpg)
Reflected Surface Waves at the
Basin Edge Love Rayleigh
fundamental
Rayleigh
1st higher mode
![Page 15: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/15.jpg)
Transmitted Surface Waves
Inside the Basin
Love Rayleigh
fundamental
Rayleigh
1st higher mode
• For a Virtual source outside the Basin
• Transmission of both Love and Rayleigh waves
• Excitation of the first higher-mode Rayleigh wave at the basin edge
![Page 16: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/16.jpg)
C3-like Kernels
• An other way to observe the wavefield
• Recipe:
• Two stations as receivers (A-B)
• A backbone array as virtual sources (Z)
using noise correlations (C1)
• Correlation of correlations (C3-like) using
both ballistic and coda parts
• Result:
Map the contribution of each virtual source Z
to the C3AB at a given time τ
L. STEHLY
![Page 17: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/17.jpg)
Kernel
3-9s
Expected Fresnel zone for a ballistic
surface wave between two stations:
ZA – ZB > AB – λ/4
• One C3 for
each virtual
source
• Comparing
theoretical
and empirical
Fresnel zones
A B
Z
A B
Z
![Page 18: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/18.jpg)
Kernel
3-9s
• Comparing
theoretical
and empirical
Fresnel zones
• One C3 for
each virtual
source
![Page 19: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/19.jpg)
Kernel
1-3s
• Comparing
theoretical
and empirical
Fresnel zones
• One C3 for
each virtual
source
![Page 20: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/20.jpg)
Kernel
1-3s
• Comparing
theoretical
and empirical
Fresnel zones
• One C3 for
each virtual
source
![Page 21: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/21.jpg)
Conclusions
• Ambient noise correlation functions catch complex propagation features in the Kanto basin
• Higher-mode surface waves following the basin shape
• Reflections of surface waves (West of Tokyo)
• Higher mode excitation at the basin edge
• It can be used both for high resolution imaging and ground motion prediction (At least up to 1s)
• Ambient noise Imaging Vs. Simulation …
• Migration to map the basin edge reflector …
SPECFEM 3D
Work in
progress ...
Andrea Colombi
![Page 22: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/22.jpg)
A1 - Theoretical Dispersion
in the 3km Deep Basin
![Page 23: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/23.jpg)
A2 – Osculation Point
![Page 24: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/24.jpg)
A3 - Propagation from the
Array Center
![Page 25: CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE ... · CHARACTERIZING BASIN SCALE WAVEFIELDS USING A DENSE SEISMIC ARRAY Pierre BOUÉ Marine DENOLLE Naoshi HIRATA Shigeki NAKAGAWA](https://reader033.vdocuments.us/reader033/viewer/2022060313/5f0b75107e708231d4309cd0/html5/thumbnails/25.jpg)
A4 - Reflected Surface Waves
Inside a Caldera