PhD in Computational Seismology, 2011 - 2015
PhD thesis topic: Bayesian inference for deep Earth structure using body waves and free oscillations of the Earth.
Research School of Earth Sciences, The Australian National University

Postgraduate Diploma in Earth System Physics, speciality in Seismology, 2010
The Abdus Salam International Center for Theoretical Physics (ICTP), Trieste, Italy

M.Sc. in Physics, speciality in Solid State Physics, 2007
Central Department of Physics, Tribhuvan University, Kathmandu, Nepal

B.Sc. in Physics, speciality in Mathematical Physics and Quantum Mechanics, 2004
Birendra Multiple Campus, Trubhuvan University, Chitwan, Nepal

Publications:

Pachhai, S., H. Tkalčić, and J. Dettmer, Bayesian inference for ultra-low velocity zones in the Earth's lowermost mantle: complex ULVZ beneath the East of the Philippines, Journal of Geophysical Research, 11 (119), 8346-8365, 2014.

Pachhai, S., J. Dettmer, and H. Tkalčić, Ultra-low velocity zones beneath the Philippine and Tasman Seas reaveled by a trans-dimensional Bayesian waveform inversion, Geophysical Journal International, 203 (2), 1302-1318, 2015.

Pachhai, H. Tkalčić, and G. Masters, Estimation of splitting functions from Earth's normal mode spectra using the neighbourhood algorithm, Geophysical Journal International, doi:10.1093/gji/ggv414, 2015.

Conference abstracts:

Masters, G., Pachhai, S., and H. Tkalčić, A new non-linear technique for measurements of splitting functions using normal modes of the Earth, AGU Fall Meet. Suppl., Abstract DI31B-4270, San Francisco, 2014.
Pachhai, S., H. Tkalčić, and J. Dettmer, New insights into ULVZs using a Bayesian inference: a case study for ULVZs beneath the east of Australia, AGU Fall Meet. Suppl., Abstract DI41A-4313, San Francisco.
Pachhai, S., H. Tkalčić, and G. Masters, A new non-linear technique for measurements of splitting functions using normal modes of the Earth, SEDI meeting, 2014.
Pachhai, S., H. Tkalčić, and J. Dettmer, Trans-dimensional Bayesian inversion for ultra low velocity zones: complex ULVZ beneath the east of the Philippines, SEDI meeting, 2014.
Pachhai, S., H. Tkalčić, and J. Dettmer, Bayesian Inversion for Ultra Low Velocity Zone Parameters in the Earth's Lowermost Mantle: Multiple-Layered Structure Confirmed Beneath the East of the Philippines, Vol. 16, EGU2014-3114, 2014.
Pachhai, S. and H. Tkalčić, Beyond Waveform Forward Modeling: The Lowermost Mantle Beneath the East of Australia, Eos Trans. AGU, 93(52), Fall Meet. Suppl., Abstract DI13A-2403, San Francisco, 2012.
Tkalčić, H., M. Sambridge, M.K. Young, T. Bodin and S. Pachhai, What Really Lies Beneath? Defying Conventional Geophysical Inversion and new Observations From the Crust to the Core, Eos Trans. AGU, 93(52), Fall Meet. Suppl.,Abstract S31C-01, San Francisco, 2012.

Scholarship and awards:

2014 ANU Vice-Chancellor's HDR Travel Grant - To attend AGU meeting in USA
2014 SEDI meeting travel grant - Present research at SEDI meeting in Japan
2012 Paterson Travel Fellowship - Visit to Harvard University
2011 King Abdullah University Excellency Award
2010 King Abdullah University Provost Award
2009 UNESCO Scholarship
2000-2006 Tribhuvan University Merit Scholarship
1999 School Leaving Certificate Exam Excellence Medal, Nepal

Research Interests:

Bayesian inference- uncertainty analysis, model selection, hierarchical Bayesian inversion, trans-dimensional Bayesian inversion.
Core mantle boundary- Non linear inversion for ultra low velocity zones (ULVZs) structure using Bayesian inference from core reflected waves.
Structure and dynamics of the inner core - Linear and non-linear inversion for inner core structure using free oscillations of the Earth, non-linear inversion based on neighbourhood algorithm and Bayesian inference from normal mode data.

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