Geology Department Postgraduate Web Pages

Name: Matthew Agius

Contact Details

Title of Project

Shear-Velocity Profiles Across the Tibetan Plateau, from Broadband Interstation Dispersion of Surface Waves.

Project details

When continents collide, they deform over hundreds and thousands of kilometers of earth’s outer layers extending over broad regions and areas – involving a three-dimensional process. Present examples of continental deformation are Tibet and the western part of North America. Much of western Europe has formed in the same way. The mechanisms of these continental deformations are not well understood, mostly due to insufficient information regarding the complex 3-D kinematics in the crust, lithospheric mantle, and asthenosphere.

In the proposed research, new surface-wave imaging methods will be applied to large new array datasets in order to constrain 3-D distributions of seismic anisotropy and infer finite strain across Tibet. The seismic constraints will be interpreted jointly with geodynamic models and then integrated into the thermomechanical modelling. The project will produce new insights into 3-D dynamics of continental deformation.

Name of supervisor

Ian Sanders (TCD)

Name of co-supervisor

Sergei Lebedev (DIAS)

Postgraduate personal details

I graduated from the University of Malta with a joint honours degree in physics and computer science. For my undergraduate project I designed a data acquisition system for a seismic station and my master’s project was developing an automated technique to locate local earthquakes using a single-station. I worked for a year as a technical officer at the University of Malta seismic unit and my job was to upgrade the acquisition systems, events database, and set up a website with various online tools. I am now following a PhD study focusing my research on Tibet.

Project Start Date

October 2008

Publications

Agius, M. R. and S. Lebedev. S-velocity structure and anisotropy of the Tibetan crust. (In prep.)

Agius, M. R. and S. Lebedev. Cold Indian shallow-angle subduction beneath Tibet from shear velocity profiles. (In prep.)

Galea P., S. D’Amico, M. R. Agius. Rift-Related  Seismicity in the Sicily Channel. (In prep.)

Fullea, J., S. Lebedev, M. R. Agius, A. G. Jones, J. C. Afonso. Lithospheric structure in the Baikal-central Mongolia region from integrated geophysical-petrological inversion of surface-wave data and topographic elevation. Geochemistry, Geophysics, Geosystems.

Agius, M. R. and P. Galea (2011), A single-station automated earthquake location system at Wied Dalam Station Malta, Seismol. Res. Lett., 82(4):545-559, doi:10.1785/gssrl.82.4.545.

Presentations:

Tibet

Agius, M. R. and S. Lebedev (2012), The shear velocity structure of the lithospheric mantle beneath Tibet. 55th IGRM, University College Cork, Ireland, 17-19 February.

Agius, M. R. and S. Lebedev (2011), The shear velocity structure of the lithospheric mantle beneath Tibet. AGU Fall Meeting, San Francisco, USA, 5-9 December.

Lebedev, S., M. R. Agius, A. J. Schaeffer (2011), Shallow-angle subduction of the Indian Plate beneath Tibet: New seismic images and implications for the evolution of the plateau. AGU Fall Meeting, San Francisco, USA, 5-9 December.

Vozar, J., J. Fullea, A. G. Jones, M. R. Agius, and S. Lebedev, (2011), Electromagnetic, seismic and petro-physical investigations of the lithosphere-asthenosphere boundary in central Tibet. AGU Fall Meeting, San Francisco, USA, 5-9 December.

Agius, M. R. and S. Lebedev (2011), The crustal and mantle structure beneath Tibet, from shear-velocity profiles. University of Malta, 4th March.

Agius, M. R. and S. Lebedev (2011), Crustal and mantle structure beneath Tibet, from shear-velocity profiles. 54th IGRM, NUI Galway, Ireland, 18-20 February.

Agius, M. R. and S. Lebedev (2010), Shear velocity profiles in the crust and lithospheric mantle across Tibet. AGU Fall Meeting, San Fransisco, USA, 13-17 December.

Agius, M. R. and S. Lebedev (2010), Lithospheric structure across the Tibetan Plateau, from broadband surface-wave analysis. Study of the Earth’s Deep Interior, 12th Symposium, Santa Barbara, California, USA, 18-23 July.

Agius, M. R. and S. Lebedev (2010), Lithospheric structure across the Tibetan Plateau, from broadband surface-wave analysis. Cooperative Institute for Dynamic Earth Research 2010 Summer Program, Kavli Institute for Theoretical Physics, University of California - Santa Barbara, USA, June 28 - July 18.

Agius, M. R. and S. Lebedev (2010), Shear-velocity profiles across the Tibetan Plateau from broadband, surface-wave, phase-velocity measurements, in Leech, M.L., and others, eds., Proceedings for the 25th Himalaya-Karakoram-Tibet Workshop: U.S. Geological Survey, Open-File Report 2010-1099, 2 p. http://pubs.usgs.gov/of/2010/1099/agius/.

Lebedev, S. and M. R. Agius (2010), Lithospheric structure and dynamics of Ti-bet: Constraints from shear-velocity distributions, in Leech, M.L., and others, eds., Proceedings for the 25th Himalaya-Karakoram-Tibet Workshop: U.S. Geological Survey, Open-File Report 2010-1099, 2 p. http://pubs.usgs.gov/of/2010/1099/lebedev/.

Agius, M. R. and S. Lebedev (2010), Crustal and lithospheric structure of Tibet from shear velocity profiles. 53rd IGRM, Belfast, Northern Ireland, 20 February.

Agius, M. R. and S. Lebedev (2009), Shear-velocity profiles across the Tibetan Plateau, from broadband interstation dispersion of surface waves. AGU Fall Meeting, 14-18 December.

Lebedev, S. and M. R. Agius (2009), Lithospheric structure of Tibet and East Asia: New constraints from surface waves. AGU Fall Meeting, San Francisco, 14-18 December

Agius, M. R. and S. Lebedev (2009), Shear-velocity profiles across the Tibetan Plateau, from broadband interstation dispersion of surface waves. INDEPTH Workshop, Dublin, Ireland, 28-30 October.

Agius, M. R. and S. Lebedev (2009), Surface-wave phase-velocity analysis across the Tibetan Plateau using broadband interstation dispersion measurements. BGA Postgraduate Research in Progress Meeting, London, Britian 10-11 September.

Agius, M. R. and S. Lebedev (2009), Surface-wave phase-velocity analysis across the Tibetan Plateau using broadband interstation dispersion measurements. The 5th International Symposium on Tibetan Plateau and the 24th Himalaya-Karakorum-Tibet Workshop, Beijing, China, 11-14 August.

Lebedev, S. and M. R. Agius (2009), Seismic structure of Tibet: new constraints from surface waves, The 5th International Symposium on Tibetan Plateau and the 24th Himalaya-Karakorum-Tibet Workshop, Beijing, China, 11-14 August.

Mongolia

Middleton D., M. R. Agius, S. Lebedev (2010) The cause of Cenozoic uplift and volcanism in Western Mongolia: A seismic study. 53rd IGRM, Belfast, Northern Ireland. 20 February.

Middleton, D., M. R. Agius, S. Lebedev (2009), Lithospheric structure of Mongolia and surroundings: A surface-wave study. AGU Fall Meeting, San Francisco, 14-18 December.

Pacific Ocean

Lynch, P., A. J. Schaeffer, M. R. Agius, S. Lebedev (2012), Robust shear-velocity profiles within oceanic lithosphere and asthenosphere: Implications for thermal and compositional structure. 55th IGRM, University College Cork, Ireland, 17-19 February.

Lynch, P., A. J. Schaeffer, M. R. Agius, S. Lebedev (2011), Robust shear-velocity profiles within oceanic lithosphere and asthenosphere: Implications for thermal and compositional structure. AGU Fall Meeting, San Francisco, USA, 5-9 December.

Ireland

S. Lebedev, C. Horan, P. W. Readman, A.J. Schaeffer, M. R. Agius, L. Collins, F. Hauser, B. M. OReilly, and T. Blake (2012), Ireland Array: A new broadband seismic network targets the structure, evolution and seismicity of Ireland and surroundings. EGU General Assembly, Vienna, Austria, 22-27 April.

Lebedev, S., P. Readman, C. Horan, A. Schaeffer, L. Collins, M. R. Agius, F. Hauser, B. O’Reilly, T. Blake (2011), Ireland Array: Broadband seismic investigation of the lithospheric structure and evolution of Ireland and surroundings. Atlantic Ireland 2011, A Petroleum Conference Organised by PIP-ISPSG, Dublin, 17 October.

Mediterranean

Neenan, E., A. J. Schaeffer, M. R. Agius, S. Lebedev (2012), The North Anatolian Fault and lithospheric deformation in eastern Mediterranean: A seismic surface- wave study. EGU General Assembly, Vienna, Austria, 22-27 April.

Neenan, E., M. R. Agius, A. J. Schaeffer, S. Lebedev (2012), The North Anatolian Fault and lithospheric dynamics in eastern Mediterranean: a seismic surface-wave study. 55th IGRM, University College Cork, Ireland, 17-19 February.

Neenan, E., M. R. Agius, A. J. Schaeffer, S. Lebedev (2011), Lithospheric anisotropy and deformation in Anatolia, Eastern Mediterranean: A seismic surface-wave study. AGU Fall Meeting, San Francisco, USA, 5-9 December.

Galea, P. amd M. R. Agius (2010), A new insight into the seismicity of the Sicily Channel. ESC 32nd General Assembly, Montpellier, France, 6-10 September.

Galea, P. amd M. R. Agius (2008), Automated Single-Station Earthquake Location in the Sicily Channel using WDD broadband station on the Maltese Islands. ESC 31st General Assembly, Crete, 7-12 September.

Agius, M. R. and Galea, P. (2008) The Seismic Monitoring and Research Unit (SMRU), University of Malta, Poster Presentation, ORFEUS Observatory Coordination Meeting, Barcelona, 5-8 May 2008.

Agius, M. R. and Galea, P. (2008) Digital Seismic Recording in Malta - 13 years on, Physics Seminar Presentation, University of Malta, 30 April 2008.

Agius, M. R. and Galea, P. (2007) Automated Single-Station Location of Earthquakes in the Central Mediterranean at WDD Station Malta, ORFEUS-NERIES Observatory Coordination Meeting, Romania, 7-10 May 2007.