Ambient noise surface wave tomography of the Makran subduction zone, south-east Iran: Implications for crustal and uppermost mantle structures

Abstract

Seismic ambient noise of surface wave tomography was applied to estimate Rayleigh wave empirical Green's functions (EGFs) and then to study crust and uppermost mantle structure beneath the Makran region in southeast Iran. 12 months of continuous data from January 2009 through January 2010, recorded at broadband seismic stations, were analyzed. Group velocities of the fundamental mode Rayleigh wave dispersion curves were obtained from the empirical Green's functions. Multiplefilter analysis was used to plot group velocity variations at periods from 10 to 50 s. Using group velocity dispersion curves, 1-D v S velocity models were calculated between several station pairs. The final results demonstrate significant agreement to known geological and tectonic features. Our tomography maps display low-velocity anomaly with SW-NE trend, comparable with volcanic arc settings of the Makran region which may be attributable to the geometry of Arabian Plate subducting beneath the overriding the Lut block. The northward subducting Arabian Plate is determined by high-velocity anomaly along the Straits of Hormuz. At short periods (\20 s), there is a sharp transition boundary between low-and high-velocity transition zone with the NW trending at the western edge of Makran which is attributable to the Minab fault system.

New Constraints for the On‐Shore Makran Subduction Zone Crustal Structure

“…(2018) inverted the Abdetedal et al. (2015) dispersion data jointly with free‐air gravity data, finding that the crust varied from an average V s ∼3.95 km s −1 and ∼33 km thick near the coast to an average V s ∼3.75 km s −1 and ∼48 km thick beneath the volcanic arc. There are three published receiver function results for CHBR (Figure 1).…”

Upper and Middle Crustal Velocity Structure of the Colombian Andes From Ambient Noise Tomography: Investigating Subduction‐Related Magmatism in the Overriding Plate

“…Indeed, an ever increasing number of ambient seismic noise studies have been produced during the last decade mapping different parts of the globe (e.g., Abdetedal et al, ; Bensen et al, ; Boué et al, ; Haned et al, ; Lin et al, ; Mottaghi et al, ; Saygin & Kennett, ; Shapiro et al, ; Stehly et al, ; Villaseñor et al, ; Ward et al, ; Yang et al, ; Yao et al, ). These studies have conclusively demonstrated that empirical Green's function recovery from average cross correlations of ambient noise between pairs of seismic stations is capable of providing tight constraints on upper and middle crustal structure.…”

High‐Resolution Lithospheric Structure of the Zagros Collision Zone and Iranian Plateau

“…Previous studies suggest a crustal thickness of ∼20–33 km for the coastal Makran (Abdetedal et al., 2015; Abdollahi et al., 2018). Our Moho map shows that in the coastal Makran, the Moho exhibits considerable undulations (Figure 5d).…”