王新 (Wang Xin)

Postdoc scholar in Geophysics, Caltech Seismological Laboratory

About Me
Research
Research

1 JGR-2019 (JGR Featured Articles)

A 3‐D Shear Wave Velocity Model for Myanmar Region

We use the newly deployed Earth Observatory of Singapore‐Myanmar broadband seismic network and other seismic stations in and around Myanmar to study the station‐based 1‐D velocity structure through a joint inversion of receiver functions, H/V amplitude ratio of Rayleigh waves, and surface wave dispersion measurements. Our results reveal a highly variable crustal structure across Myanmar region, characterized by a series of N‐S trending sedimentary basins, with thicknesses up to ~15 km in central Myanmar and an ~5‐km step in the depth of the Moho across the Sagaing‐Shan Scarp fault system. We interpolate our station‐based 1‐D velocity profiles to obtain an integrated 3‐D velocity model from southern Bangladesh to Myanmar. Using three regional earthquakes located to the south, within, and north of the seismic network, we show that our proposed model performs systematically better than the CRUST 1.0 model for both Pnl waves and surface waves.

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2 EPSL-2018

Active backstop faults in the Mentawai region of Sumatra, Indonesia, revealed by teleseismic broadband waveform modeling

Our study shows that the 2005 and 2009 “backthrust” sequences in Mentawai region actually occurred on steeply (∼60 degrees) landward-dipping faults that intersect the Sunda megathrust beneath the deepest part of the forearc basin, contradicting previous studies that inferred slip on a shallowly seaward-dipping backthrust. Static slip inversion on the newly-proposed fault fits the coseismic GPS offsets for the 2009 mainshock equally well as previous studies, but with a slip distribution more consistent with the mainshock centroid depth (∼20 km) constrained from teleseismic waveform inversion. We interpret these earthquakes as ‘unsticking’ of the Sumatran accretionary wedge along a backstop fault separating imbricated material from the stronger Sunda lithosphere. Alternatively, the reverse faults may have originated as pre-Miocene normal faults of the extended continental crust of the western Sunda margin.

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3 EPSL-2017

Double-ramp on the Main Himalayan Thrust revealed by broadband waveform modeling of the 2015 Gorkha earthquake sequence

We use the newly deployed Earth Observatory of Singapore‐Myanmar broadband seismic network and other seismic stations in and around Myanmar to study the station‐based 1‐D velocity structure through a joint inversion of receiver functions, H/V amplitude ratio of Rayleigh waves, and surface wave dispersion measurements. Our results reveal a highly variable crustal structure across Myanmar region, characterized by a series of N‐S trending sedimentary basins, with thicknesses up to ~15 km in central Myanmar and an ~5‐km step in the depth of the Moho across the Sagaing‐Shan Scarp fault system. We interpolate our station‐based 1‐D velocity profiles to obtain an integrated 3‐D velocity model from southern Bangladesh to Myanmar. Using three regional earthquakes located to the south, within, and north of the seismic network, we show that our proposed model performs systematically better than the CRUST 1.0 model for both Pnl waves and surface waves.

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4 JGR-2017

Topography of the 410 km and 660 km discontinuities beneath the Japan Sea and adjacent regions by analysis of multiple‐ScS waves

The Northwest Pacific subduction region is an ideal location to study the interaction between the subducting slab and upper mantle discontinuities. Due to the sparse distribution of seismic stations in the sea, previous studies mostly focus on Mantle Transition Zone (MTZ) structures beneath continents or island arcs, leaving the vast area of the Japan Sea and Okhotsk Sea untouched. In this study, we analyzed multiple-ScS reverberation waves, and a common-reflection-point stacking technique was applied to enhance consistent signals beneath reflection points. A topographic image of the 410-km and 660-km discontinuities is obtained beneath the Japan Sea and adjacent regions.

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5 SRL-2016

Seismic Sensor Misorientation Measurement Using P‐Wave Particle Motion: An Application to the NECsaids Array

Seismic sensor orientation is one of the most critical parameters for modern three‐component seismological observation. However, this parameter is easily subject to error imposed by strong magnetic anomalies near the station or by human error in declination calibration. It is therefore very important to inspect and correct for sensor misorientation before utilizing three‐component waveform data. We applied principal component analysis and the minimizing transverse energy method to measure the epoch‐dependent sensor misorientation for our temporary seismic array. Our results show high consistency with the direct gyrocompass measurements, with a correlation coefficient of 0.95. Our statistical analysis suggests that we can estimate robust sensor misorientation utilizing 10 earthquakes with high signal‐to‐noise ratio records and highly linear P‐wave polarizations. We also find that the influence of anisotropy or a dipping interface produces a periodical pattern with back azimuth and is relatively small for our misorientation estimation.

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Publications

Submitted

?. Wang, X., Q. F. Chen, F. Niu, S. Wei, J. Y. Ning, J. Li, W. Wang, Sub-slab Partial Melting within the Hydrous Mantle Transition Zone (Under review, NatureGeoscience)

2019

11. Ross, Z. E., Idini, B., Jia, Z., Stephenson, O. L., Zhong, M., Wang, X., et al. (2019). Hierarchical interlocked orthogonal faulting in the 2019 Ridgecrest earthquake sequence. Science, 336(6463), 346-351

10. Wang, X., Zhong, Z., (2019). Moving from 1-D to 3-D velocity model: automated waveform-based earthquake moment tensor inversion in the Los Angeles region Geophysical Journal International, 220.

9. Adebayo Oluwaseun Ojo, Li Zhao, X. Wang, (2019). Estimations of Sensor Misorientation for Broadband Seismic Stations in and around Africa. Seismological Research Letters, 90.

8. Wang, X., Wei, S., Wang, Y., Maung Maung, P., Hubbard, J., Banerjee, P., et al. (2019). A 3‐D Shear Wave Velocity Model for Myanmar Region. Journal of Geophysical Research: Solid Earth, 124.

2018

7. Materna, K., S. Wei, X. Wang, H. Luo, T. Wang, R. Salman, R. Bürgmann (2018), Source characteristics of the 2017 Mw 6.4 Moijabana, Botswanan earthquake, a rare lower-crustal event within an ancient zone of weakness, Earth Planet. Sci. Lett., 506:348-359

6. Wang, X., K. Bradley, S. Wei (2018), Active backstop faults in the Mentawai region of Sumatra, Indonesia, revealed by teleseismic broadband waveform modeling, Earth Planet. Sci. Lett., 483, 29-38.

2017

5. Wang, X., S. Wei, and W. Wu (2017), Double-ramp on the Main Himalayan Thrust revealed by broadband waveform modeling of the 2015 Gorkha earthquake sequence, Earth Planet. Sci. Lett., 473, 83-93.

4. Wang, X., J. Li, and Q. F. Chen (2017), Topography of the 410 km and 660 km discontinuities beneath the Japan Sea and adjacent regions by analysis of multiple‐ScS waves, Journal of Geophysical Research: Solid Earth, 122(2), 1264-1283

3. Wang, Y., S. Wei, X. Wang, E. O. Lindsey, F. Tongkul, P. Tapponnier, K. Bradley, C.-H. Chan, E. M. Hill, and K. Sieh (2017), The 2015 Mw 6.0 Mt. Kinabalu earthquake: an infrequent fault rupture within the Crocker fault system of East Malaysia, Geoscience Letters, 4(1), 6.

2013-2016

2. Wang, X., Q. F. Chen, J. Li, and S. J. Wei (2016), Seismic Sensor Misorientation Measurement Using P-Wave Particle Motion: An Application to the NECsaids Array, Seismological Research Letters, 84(4), 901-911, doi:10.1785/0220160005.

1. Li, J., X. Wang, X. J. Wang, and D. A. Yuen (2013), P and SH velocity structure in the upper mantle beneath Northeast China: Evidence for a stagnant slab in hydrous mantle transition zone, Earth Planet. Sci. Lett., 367, 71-81, doi:10.1016/j.epsl.2013.02.026.

Resource

2019 AGU Poster - Seismotectnoics and fault geometries of the 2019 Ridgecrest sequence: insight from aftershock moment tensor catalog using 3D Green’s functions Download

Contact Me

Seismological Laboratory,    California Institute of Technology

1200 E. California Blvd.,     MC 252-21, Pasadena, CA 91125

Phone: (626)395-1436        Email: xinwang@caltech.edu