New insights into the structural heterogeneity and geodynamics of the Indo-Burma subduction zone from ambient noise tomography

The January 11, 2018, Mw 6.0 Bago‐Yoma, Myanmar Earthquake: A Shallow Thrust Event Within the Deforming Bago‐Yoma Range

“…The Pnl segment shows multiple arrivals possibly from a mix of reflected and depth phases, making it difficult to determine the depth phases for constraining the focal depth (Figure 6b). The surface wave segment shows a relatively large amplitude coda that extends for tens of seconds for stations located on hard rock and longer for stations located within the CMB (Figure S10), as also revealed by previous studies (X. Wang et al., 2019; Wu et al., 2021). Therefore, a 1D velocity model is not able to adequately model the waveforms recorded at these stations at sufficiently high frequencies to replicate the complicated Pnl arrivals.…”

Azimuthal Anisotropy Tomography of the Southeast Asia Subduction System

“…Seismic tomography is a powerful tool to image the crustal and mantle structure of the Earth, which has been used by many researchers to study the three‐dimensional (3‐D) velocity structure of the SE Asia subduction system (e.g., Harmon et al., 2012; Huang et al., 2015; Koulakov et al., 2016; Lebedev & Nolet, 2003; Li & van der Hilst, 2010; Li et al., 2018; Liu et al., 2019; Wu et al., 2021; Zhao et al., 2021). Global and regional tomographic studies have detected significant high‐velocity (high‐V) zones in the MTZ beneath much of the SE Asia region, which are interpreted as subducted slabs trapped within the MTZ (e.g., Simmons et al., 2012; Zhao, 2004).…”

Seismic structure across central Myanmar from joint inversion of receiver functions and Rayleigh wave dispersion

“…However, the majority of these studies concentrate on the upper mantle velocity features beneath Myanmar, and thus provide limited information on the shallow (i.e., <100 km depth) structure of the study region. Since digital broadband networks began to be set up in 2016, regional 3-D crustal shear velocity model of Myanmar have been obtained by either joint inversion of receiver functions (RFs), Rayleigh wave dispersion and ellipticity (Wang et al, 2019) or ambient noise tomography (Wu et al, 2021). These models provide constraints on the main structures such as the sedimentary basin and the Moho discontinuity, but the average station spacing in these studies was ~150 km.…”