The Makran Subduction Zone (Figure 1), which extends ∼1,000 km from the Strait of Hormuz in the west to Sonmiani Bay near Karachi in the east, results from the ongoing northward subduction of the Arabian Sea Plate beneath southeastern Iran and southwestern Pakistan. It is characterized by a shallow, gently-dipping subduction interface (e.g., Kopp et al., 2000;Smith et al., 2012), a high sedimentation rate (e.g., Ellouz-Zimmermann, Deville, et al., 2007;McCall, 1997), an extremely broad accretionary prism which is largely sub-aerial and no bathymetric trench. While great historic earthquakes (e.g., Byrne et al., 1992) accompanied by tsunamis (e.g., Hoffmann et al., 2013) have occurred on the Makran Subduction Zone, in general, seismicity is low, especially in the western Makran (e.g., Engdahl et al., 2006). A number of studies have focused on the structure of the offshore Makran accretionary prism (e.g., Kopp et al., 2000;Smith et al., 2012) and teleseismic tomographic studies show a high-velocity, steep northward-dipping feature in the upper mantle beneath southern Iran and Pakistan (e.g., Van der Meer et al., 2018). However, although the Makran Subduction Zone is the primary seismological