Crustal structure beneath the Sumatra Island from teleseismic receiver functions
Danh-Hung Tran1,2 and Ting Yang1
1
State Key Laboratory of Marine Geology, Tongji University, Shanghai, PR China
E-mail: 36hungtd@tongji.edu.cn
2
Oil and Gas Faculty, Hanoi University of Mining and Geology, Hanoi, Vietnam
Sumatra Island is an active subduction zone where the Indian-Australian Plate is subducted into
the Eurasian Plate along the Sunda Trench. The crustal structure beneath this region is important
to our understandings of the dynamic processes of subduction and its seismogenic zone. In this
study, we use the technique of teleseismic receiver function to investigate the crustal thickness
and Vp/Vs ratio of this region. The H- algorithm using the delay times of the Moho P-to-S
converted phases is employed to determine the thickness and the Vp/Vs ratio. To enhance the
signal-to-noise ratio of the receiver function, we compute and stack receiver functions from a
group of earthquakes for each station. Our preliminary result shows that crustal thickness has a
strong variation along the trench. The average thickness of the crust is 42.3 km with a ranges of
37 km to 47 km. A relatively low Vp/Vs ratio (1.63) is derived. These results may have
implications on the characteristics of the rupture zone along the trench.