Professor Hrvoje Tkalčić FAA

Head of Geophysics
Research School
of Earth Sciences,
The Australian National University
Canberra, ACT 0200, AUSTRALIA
tel: +61-2-6125 3213
fax: +61-2-6257 2737
Email: Hrvoje.Tkalcic @ anu.edu.au
orcid.org/0000-0001-7072-490X
I use seismology and mathematical geophysics tools to understand the internal workings of our
planet. You can think of these tools together as of an internal telescope through which we image Earth's structure and
dynamics.
| With students and postdoctoral researchers in Canberra (2023). From left to right:
Zhihan Liu, MSc student, Dr Xiaolong Ma, Dr Zhi Wei,Abhay Pandey, PhD student, Jiarun Zhou, MSc student,
Jinyin Hu, PhD student, Thuany Costa de Lima, PhD student, Dr Thanh-Son Pham, Tianyu Cui (visiting
student), Dr Sheng Wang. Photo credit: Nita Sebastian, PhD student. |
| Review paper on
Coda-correlation wavefield |
Review paper on
Earth's inner core |
Video on Inge Lehmann by AGU |
Video on Research Excellence Award by
Auscope |
| Video on discovery of J waves by ANU TV |
Seismological Society of America At Work column |
International Innovations article |
ABC news on discovery of shuffling inner core rotation |
Cover_inner_core_rotation1_small.jpg
Current and recent grants
2022-2024 ARC Discovery Grant DP220102815 ($$$$) "A new journey to the Earth's inner core: A planet within a planet" (Tkalčić, L. Waszek);
2020-2022 ARC Discovery Grant DP200101854 ($$$$) "Probing the Australian-Pacific plate boundary: Macquarie Ridge in 3D" (Tkalčić, C. Eakin, M. Coffin, N. Rawlinson, J. Stock);
2020-2021 ARC LIEF Grant LE200100086 ($$$) "Rapid Deployment Seismic Recorders for Interdisciplinary Antarctic Research" (Reading, A., S. King, H. Tkalčić, B. Kulessa);
2020-2022 USA DoE/AFRL Grant ($$$) "Towards improved understanding of seismic moment tensors: Utilizing high-resolution Earth model with accompanying uncertainty within hierarchical Bayesian inversion framework" (Tkalčić, H., S. Kim);
2020-2021 Marine National Facility Grant ($$$$) "Macquarie Ridge in 3D: Recovery" (Tkalčić, H., C. Eakin, M. Coffin,
N. Rawlinson, J. Stock);
2019-2020 Marine National Facility Grant ($$$$) "Macquarie Ridge in 3D: Deployment" (Tkalčić, H., C. Eakin, M. Coffin,
N. Rawlinson, J. Stock);
2014-2017 ARC Discovery Grant DP140102533 ($$) "Rapid determination of earthquake sources in Australia" (Tkalčić, H., A. Fichtner);
2013-2016 ARC Linkage Grant LP130100413 ($$$$) "Craton modification and growth: The east Albany-Fraser Orogen in 3-D" (Tkalčić, H., Kennett,
C. Spaggiari, K. Gessner);
2013-2015 ARC Discovery Grant DP130101473 ($$$) "Multi-array, multi-frequency probing of the Earth's heterogeneity" (Tkalčić, H., Kennett,
S. Tanaka);
2013-2016 USA DoD/AFRL Grant ($$$$) "Improved Earth structure in Northeast Asia and seismic moment tensor$
partition modeling" (Tkalčić, Y. Chen, J. Rhie, S. Ford)
A DETECTION OF RICOCHET WAVES & CONFIRMING THE INNERMOST INNER CORE
The image above illustrates the ricochet waves detection and sampling of the innermost inner core. Image credit: Drew Whitehouse (NCI Vizlab),
Thanh-Son Phạm and Hrvoje Tkalčić
Open Access to Article here.
News selection:
ANU Press Release
New York Times
CNN
SCANNING THE PLANETARY CORES: THE MARS' CORE
The image above illustrates the principle of the Mars' core detection using the inter-source correlation. Image credit: Sheng Wang and Hrvoje Tkalčić
Free Access to Article here.
News selection:
ANU Press Release
APAC Network
A DETECTION OF J (SHEAR) WAVES IN THE EARTH'S INNER CORE
The image above illustrates the principle of J waves detection. Image credit: Thanh-Son Phạm and Hrvoje Tkalčić
Free Access to Article on the Publications page (with a permission from AAAS/Science)
News selection:
ANU Press Release
ANU TV
ABC News
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STRONG, MULTI-SCALE HETEROGENEITY IN EARTH'S LOWERMOST MANTLE Click on the image above to find out more about heterogeneity in the lowermost mantle.
Free Software
IRFFM 2 - Interactive Receiver Functions Forward Modeller
2
v1.2
(JOINT INVERSION OF RECEIVER FUNCTIONS AND SURFACE WAVE DISPERSION)
Publications
Curriculum Vitae
News and media 
Opportunities for students
PHYS3070 Course material
Research Interests
The Australian Outback through my lens
A look inside a volcano: Le Piton de la Fournaise, La Reunion Island
Free Software
IRFFM (Interactive Receiver Functions Forward Modeller)
v1.1
RESEARCH HIGHLIGHTS
SHUFFLING ROTATION OF THE EARTH'S INNER CORE Click on the image above to find out more about rotational dynamics of
the inner core.
CANDY WRAPPER FOR THE EARTH'S INNER CORE Click on the candy to find out more about the reconciliation of mineral physics predictions and
seismological observations of inner core structure.
INNER CORE SAMPLING BY PKP WAVES VIDEO
Click on the image above to see an animation of our current spatial coverage of the inner core
by PKP waves. Uneven distribution of large earthquakes and seismic stations installed worldwide
limits this sampling. More installations are needed to help advance our understanding of the deep
Earth.
The PKP dataset and tomographic model are from Tkalčić et al.,
GJI 2002, Leykam et al., GJI 2010, and Tkalčić, GRL 2010. Green dots are station-,
while red dots are earthquake-locations. The yellow sphere is the Earth's inner core, seen through the
compressional velocity field observed for the lowermost mantle. Blue lines are fast,
and red lines are slow ray-paths through the Earth. This animation is made in collaboration with NCI's Rhys Hawkins.
Source: "The Earth's inner core: revealed by observational seismology>", H. Tkalčić, in preparation
Watch another video of inner core sampling (without lowermost mantle structure) on youtube
INNER CORE AS A CONGLOMERATE OF ANISOTROPIC DOMAINS Click on the image above to find out more about recent research on
the inner core.
BENFORD'S LAW IN GEOSCIENCES
More about this topic under News and media.
For more information, see research pages of Malcolm Sambridge.
VOLCANIC EARTHQUAKES IN ICELAND WITH ANOMALOUS SEISMIC
RADIATION Click on the image above to find out more about recent research on
anomalous earthquakes in Iceland.
SMALL-SCALE HETEROGENEITY OR PARTIAL
MELT IN THE UPPER MANTLE POSTULATED FROM FIRST OBSERVATIONS AND MODELING
OF "PODAL" PKPPKP WAVES AND THEIR PRECURSORS Click on the MPEG icon to watch a movie
showing PKPPKP main phase at lower frequencies, and prominent PKPPKP
precursors at higher frequencies, for an Alaskan earthquake observed at
the ILAR array. These precursors are interpreted as reflections from the
upper mantle heterogeneity between 150 and 220 km depth.
Click on
the image above to find out more about the first observations of "podal"
PKPPKP waves and their precursors.
LARGE POLARIZATION ANISOTROPY IN THE
MANTLE OBSERVED THROUGH MULTI-STEP MODELING OF RECEIVER FUNCTIONS AND SURFACE
WAVES Click on the image above to find out more
about multi-step modeling of receiver functions and surface wave dispersion, and
the observation of large polarization anisotropy in the upper mantle.
COMPRESSIONAL VELOCITY MODEL OF THE LOWERMOST
MANTLE Click on the
image above for more details on P wave tomography of the Earth's lowermost mantle using PKP
and PcP waves and implications for anisotropy in the inner core. You are welcome to
download TRH_KC model with plotting instructions and figures.
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