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Research School of Earth Sciences - Hrvoje Tkalčić - STUDENTS

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N.B. The scholarships are based on academic merit. Domestic studets with First-class Honors degrees are encouraged to apply for a PhD program and have a great chance to secure a financial support. The PhD admission process for international students is highly competitive, with only a small number of outstanding students receiving an ANU scholarship each academic year.

Current PhD students: Surya, Mallory, Marija and Tanja, autumn 2013, H.T.

Another photo taken in autumn, 2013, H.T.
To see other research interests in seismology at RSES, please visit home pages of my colleagues:

Link to Jan Dettmer's home page

Link to Malcolm Sambridge's home page

Link to Brian L. N. Kennett's home page

Link to Rhodri Davies' home page

Degree: PhD, PhB, Honours, M.Sc., Summer Scholar Projects, Internships

Subject: Deep Earth/Continent evolution, Physics, Geophysics, Seismology and earthquakes

New constraints on the Earth's inner core anisotropy from seismic body waves

We live in a decade of unprecedented quantity and quality of seismic data, which are easily accessible online. Although the quality of seismic records is improving constantly, there are still vast amounts of unanalysed seismic waveforms, which might hold a key to deciphering unresolved geophysical puzzles. One such puzzle is the inner core structure. The inner core was discovered in 1936, and inner core anisotropy (directional dependence of elastic properties) was hypothesised fifty years later, to explain anomalous travel times of core-sensitive seismic waves. Some recent results suggest the existence of "innermost inner core". However, inadequate spatial sampling of the central inner core by seismic waves makes further advances on this topic very challenging. This project will focus on finding new ways of sampling the centre of the Earth and interpreting the results in the context of our planet's dynamics and evolution. Interested students with a physics or maths background are invited to contact the supervisor directly at to discuss possibilities.

Degree: PhB, Honours, M.Sc., Summer Scholar Projects

Subject: Deep Earth/Continent evolution, Physics, Geophysics, Seismology and earthquakes

Planet's internal rotation

This topic is a subject of active research in geophysical community and was exploited in a recent science-fiction motion picture The Core (although the scientific facts in the movie were misrepresented to enhance entertainment). A differential rotation of the inner core with respect to the rest of the mantle was first suggested from numerical simulations of the geodynamo. Since then, seismological studies aiming to detect differential rotation of the inner core using temporal changes in seismic waveforms were controversial and often criticised. One reason for scrutinizing seismological results was inadequate precision to resolve small temporal changes in inner core properties. However, after the turn of the millennium, earthquake doublets (repetitive earthquakes that are much less subjected to uncertainties stemming from possible errors in source parameter determination and structure in the mantle) have been used to confirm the differential rotation of the inner core. At the same time, the results from normal modes of the Earth were in odds with the existance of a significant differential rotation. We have recently discovered that the differential rotation of the inner core with respect to the mantle is variable in time, which reconciled the old discrepancy in the results from the earthquake doublets and normal modes studies. We found that the inner core accelerated and decelerated more in recent years, but more data are needed to confirm this observation. This project is twofold: we will explore a unique dataset from the Australian seismic stations in a search for new doublets, and we will collect and explore a global dataset of normal modes to approach inner core rotational dynamics from an independent prospective. A highly motivated student with a background in geophysics, physics, astronomy or mathematics will find the project challenging and satisfying. Please contact the supervisor directly at for more information.

Degree: PhD, PhB, Honours, M.Sc., Summer Scholar Projects

Subject: Deep Earth/Continent evolution, Geophysics, Seismology and earthquakes, Computational

Studying crustal and upper mantle structure beneath Australia using multiple geophysical datasets

Seismologists combine the so-called receiver functions and surface wave data to improve the general understanding of crustal and upper mantle structure in various regions of the world. An important humanitarian objective of obtaining improved structural models is better understanding of the seismicity and hazard assessment for the region of study. Receiver functions are mostly sensitive to sharp gradients in Earth's elastic properties (such as the Moho discontinuity), while surface wave data contribute to a better understanding of overall seismic wave speeds. We are working to develop a reliable method for the joint modeling of these two types of data, possibly with independent information from seismic "noise". This project will focus on applying this method to the data collected by the seismic stations at various regions to better constrain crustal and upper mantle structure, including features such as the crustal thickness, upper mantle low-velocity zone and transverse isotropy (polarization anisotropy). Students with a strong computer science, physics or mathematics background including familiarity with Unix are invited to contact the supervisor at for more information.

Degree: PhD, PhB, Honours, M.Sc., Summer Scholar Projects

Subject: Seismology and earthquakes, Geophysics, Computational, Deep Earth/Continent evolution

The seismic sources

Improved structural models of the Earth and the knowledge about seismic wave propagation allow seismologists to study earthquake mechanisms. The earthquakes could most generally be divided to tectonic and volcanic. The far-field radiation of most tectonic earthquakes can be conveniently described with the so-called double-couple system of forces. However, a full seismic moment tensor representation is more complete form of the mathematical representation of seismic sources, especially in non-tectonic environments. Of particular interest are seismic events with anomalous seismic radiation and puzzling focal mechanisms, such as volcanic earthquakes, mid-ocean ridge events or explosions.Different computational methods are used to reveal statistically significant non-double-couple components of the moment tensor and model complex finite sources. A student with maths and physics background and strong analytical skills is invited to join the project and assist with analysis and interpretation of results. Please contact the supervisor directly at for more information.

Link to Project Finder (other research projects at RSES)
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