Crustal thickness and velocity structure of southern Peninsular Malaysia


Author : Abdul Halim Abdul Latiff & Amin Esmail KhalilPublication : Bulletin of the Geological Society of MalaysiaNo. : 66Page : 7 - 13Year : 2018DOI : https://doi.org/10.7186/bgsm66201802


Description

Bulletin of the Geological Society of Malaysia, No. 66, December 2018, pp. 7 – 13

Crustal thickness and velocity structure of southern Peninsular Malaysia

Abdul Halim Abdul Latiff1,2,* & Amin Esmail Khalil2

1Department of Geosicences, UniversitiTeknologi PETRONAS, 32610 Bandar Seri Iskandar, Perak, Malaysia
2School of Physics, Universiti Sains Malaysia, Gelugor 11900 Pulau Pinang, Malaysia
*Corresponding author email address: abdulhalim.alatiff@utp.edu.my

Abstract: The tectonic setting of Peninsular Malaysia can be described by three distinctive stratigraphic belts, known as western, central and eastern belts. These western and eastern belts which were formed during the Paleo-Tethys subduction process in the Late Paleozoic are separated by the Bentong-Raub suture zone. Although various study had already evaluated this formation process, the geological detail of the region’s crust is still relatively unknown. The velocity and detail information of the Earth’s crust is crucial in determining the earthquake’s location and seismic hazard. The best way to acquire this information is through the receiver function method. The receiver function is computed from the tele-seismic earthquake waveform which involves P-wave, P-S wave as well as pPpS and pSpS + pPsS multiple phases recorded by a three-component seismogram. In this work, the data recorded at the two broadband seismometer stations located in Kota Tinggi, Johor and Bukit Timah, Singapore, were processed and analyzed through the receiver function methodology. Then the crustal thickness beneath the two seismometer stations were estimated through H-k stacking method before the waveform was inverted twice for the final 1-D velocity profile of the region. A total of 889 (for Kota Tinggi station) and 693 (for Bukit Timah station) tele-seismic earthquakes which occurred between 2005 and 2016, were evaluated for the crustal thickness and velocity structure analysis. From the H-k thickness analysis, the crust-mantle boundary was found at 34 km and 30 km for region beneath Kota Tinggi and Bukit Timah stations respectively. In addition, the 1-D velocity profile from the inverted waveform indicate a gradual velocity increment from Conrad boundary (around 10-12 km depth) to Moho thickness in both cases. The findings of these stations’ crustal thickness are consistent with the past findings which imply that the thickness for southern Peninsular Malaysia (Johor region) and Singapore is within the 30-35 km.

Keywords: Receiver function, crustal thickness, velocity structure, Peninsular Malaysia

https://doi.org/10.7186/bgsm66201802