TY  - JOUR
A1  - Kieling, Katrin
A1  - Rößler, Dirk
A1  - Krüger, Frank
T1  - Receiver function study in northern Sumatra and the Malaysian peninsula
JF  - Journal of seismology
N2  - In this receiver function study, we investigate the structure of the crust beneath six seismic broadband stations close to the Sunda Arc formed by subduction of the Indo-Australian under the Sunda plate. We apply three different methods to analyse receiver functions at single stations. A recently developed algorithm determines absolute shear-wave velocities from observed frequency-dependent apparent incidence angles of P waves. Using waveform inversion of receiver functions and a modified Zhu and Kanamori algorithm, properties of discontinuities such as depth, velocity contrast, and sharpness are determined. The combination of the methods leads to robust results. The approach is validated by synthetic tests. Stations located on Malaysia show high-shear-wave velocities (V (S)) near the surface in the range of 3.4-3.6 km s (-aEuro parts per thousand 1) attributed to crystalline rocks and 3.6-4.0 km s (-aEuro parts per thousand 1) in the lower crust. Upper and lower crust are clearly separated, the Moho is found at normal depths of 30-34 km where it forms a sharp discontinuity at station KUM or a gradient at stations IPM and KOM. For stations close to the subduction zone (BSI, GSI and PSI) complexity within the crust is high. Near the surface low V (S) of 2.6-2.9 km s (-aEuro parts per thousand 1) indicate sediment layers. High V (S) of 4.2 km s (-aEuro parts per thousand 1) are found at depth greater than 6 and 2 km at BSI and PSI, respectively. There, the Moho is located at 37 and 40 km depth. At station GSI, situated closest to the trench, the subducting slab is imaged as a north-east dipping structure separated from the sediment layer by a 10 km wide gradient in V (S) between 10 and 20 km depth. Within the subducting slab V (S) a parts per thousand aEuro parts per thousand 4.7 km s (-aEuro parts per thousand 1). At station BSI, the subducting slab is found at depth between 90 and 110 km dipping 20A degrees +/- 8A degrees in approximately N 60A degrees E. A velocity increase in similar depth is indicated at station PSI, however no evidence for a dipping layer is found.
KW  - Receiver functions
KW  - Absolute shear-wave velocity
KW  - Sumatra
KW  - Subduction zone structure
Y1  - 2011
U6  - https://doi.org/10.1007/s10950-010-9222-7
SN  - 1383-4649
VL  - 15
IS  - 2
SP  - 235
EP  - 259
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Mechie, James
A1  - Ben-Avraham, Zvi
A1  - Weber, Michael H.
A1  - Götze, Hans-Jürgen
A1  - Koulakov, Ivan
A1  - Mohsen, A.
A1  - Stiller, M.
T1  - The distribution of Moho depths beneath the Arabian plate and margins
JF  - TECTONOPHYSICS
N2  - In this study three new maps of Moho depths beneath the Arabian plate and margins are presented. The first map is based on the combined gravity model, EIGEN 06C, which includes data from satellite missions and ground-based studies, and thus covers the whole region between 31 degrees E and 60 inverted perpendicular E and between 12 degrees N and 36 degrees N. The second map is based on seismological and ground-based gravity data while the third map is based only on seismological data. Both these maps show gaps due to lack of data coverage especially in the interior of the Arabian plate. Beneath the interior of the Arabian plate the Moho lies between 32 and 45 km depth below sea level. There is a tendency for higher Pn and Sn velocities beneath the northeastern parts of the plate interior with respect to the southwestern parts of the plate interior. Across the northern, destructive margin with the Eurasian plate, the Moho depths increase to over 50 km beneath the Zagros mountains. Across the conservative western margin, the Dead Sea Transform (DST). Moho depths decrease from almost 40 km beneath the highlands east of the DST to about 21-23 km under the southeastern Mediterranean Sea. This decrease seems to be modulated by a slight depression in the Moho beneath the southern DST. The constructive southwestern and southeastern margins of the Arabian plate also show the Moho shallowing from the plate interior towards the plate boundaries. A comparison of the abruptness of the Moho shallowing between the margins of the Arabian plate, the conjugate African margin at 26 degrees N and several Atlantic margins shows a complex picture and suggests that the abruptness of the Moho shallowing may reflect fundamental differences in the original structure of the margins. (C) 2012 Elsevier B.V. All rights reserved.
KW  - Moho depths
KW  - Arabian plate
KW  - Red Sea
KW  - Velocity models
KW  - Receiver functions
KW  - Satellite gravity data
Y1  - 2013
U6  - https://doi.org/10.1016/j.tecto.2012.11.015
SN  - 0040-1951
SN  - 1879-3266
VL  - 609
SP  - 234
EP  - 249
PB  - ELSEVIER SCIENCE BV
CY  - AMSTERDAM
ER  -