“…The regional crustal structure of the RA‐trough system has been investigated mainly relying on seismic reflection/refraction profiles (Arai et al., 2018; Hirata et al., 1991; Iwasaki et al., 1990; Klingelhoefer et al., 2009; Kodaira et al., 1996; N. S. Li, 2001; T. K. Wang et al., 2004; K. McIntosh et al., 2005; Nishizawa et al., 2019), regional body wave and surface wave tomography (Chou et al., 2009; Friederich, 2003; Gorbatov & Kennett, 2003; Huang et al., 2014; Nakamura & Umedu, 2009; Nakamura et al., 2003; Tao et al., 2018; Wang et al., 2008, 2017), magnetic (J. Y. Gao et al., 2008; Liang et al., 2001), and gravity data analysis (J. Y. Gao et al., 2008; Han et al., 2007; Jin et al., 1983).…”