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ACT Tech talk: My Journey in Geophysics

Thursday, November 30, 2023

Title: My Journey in Geophysics


Roger Miller / Geoscience Australia

Ravin Deo/ Geoscience Australia

Date and Time: 5:00pm (AEDT time), 30th Nov 2023


Roger Miller graduated from University of Leicester (UK) with BSc (Hons) in Geophysics (Geological) in 1993 at the height of an industry downturn in Europe. After 2 years of temporary work he got his first role in the geophysics industry as a field geophysicist acquiring CSAMT, TDEM and MT, before travelling to Australia and finding employment as a Geophysical Project Manager, responsible for safe operations of geophysical field crews, often in remote areas and overseas. He has predominantly worked in industry with Fugro Ground Geophysics, Fugro Engineering Services, Fugro Airborne Surveys, Seabed Geosolutions and Petronas Carigali before joining Geoscience Australia in October this year. He has over 25 years’ experience in the interpretation and integration of multiple geophysical, geological and supplementary datasets, specialised in hydrocarbon and mineral exploration and shallow geophysics, utilising a combination of gravity gradiometry (FTG and FALCON), gravity, magnetic, marine CSEM/MT, seismic, airborne TDEM and well log data.

Ravin Deo recently joined Geoscience Australia as a geophysicist and comes from academia with experiences in Fiji and Australia. His experiences from the wider applied physics field imparts in him skills to approach a complex and technically challenging problem from various perspectives simultaneously. He has experience in numerical modelling and developing instrumentation and sensors for measurement and assessment and has strong expertise in geophysical systems for practical near-surface applications.   

ACT Tech Talk: An Interactive workflow for MT data using open-source packages and HPC

Thursday, November 23, 2023
1600 AEST
1640 AEST

Title: An Interactive workflow for MT data using open-source packages and HPC

Presenters: Jared Peacock (USGS) and Karl Kappler (DIAS Geophysical and Space Science Institute)

Date and time: 4pm (AEST time), 23rd Nov 2023


The magnetotelluric (MT) community has traditionally been composed of specialists, however with the advancement of accessibility to equipment, data, and high-performance computing more non-specialists are interested in MT data.  Open-source tools exists for working with MT data; however no publicly available coherent workflow exists.  We present a workflow for MT data that demonstrates how to use existing open-source software packages to go from raw data to a 3D resistivity model. This workflow increases the capacity of MT data to be used for open science following FAIR principles.


  1. Jared Peacock is a research geophysicist at the Geology, Minerals, Energy, and Geophysics Science Center in Menlo Park, CA. He received his Ph.D. from the University of Adelaide and B.Sc. and M.Sc. from the Colorado School of Mines, all in geophysics. Since joining the USGS In 2013, his expertise is in magnetotellurics, focusing on characterizing volcanic, geothermal, and mineral systems in 3D.
  2. Karl Kappler has held roles in the development of remote sensing and digital data processing technologies, mostly in electromagnetics and acoustics with applications ranging from unexploded ordnance, resource exploration, and borehole investigations to measurements while drilling. Karl received MS and PhD degrees in Engineering Geoscience from the University of California at Berkeley after completing a BSc in Mathematics and Physics at the University of Victoria.  Karl is an active contributor to MTH5, mt_metadata and the main developer of aurora, hosted by UBC’s SimPEG. Karl currently acts in the role of Magnetotelluric Specialist within DIAS Geophysical's R&D team in his native Canada and is also an Affiliate Research Scientist at the Space Science Institute in the USA."

Teams link: 

Click here to join the meeting

Meeting ID: 473 171 286 566
Passcode: fyja3r

ACT tech talk: What we can and cannot know from unconstrained inversion of regional magnetic field data

Wednesday, September 27, 2023

Title: What we can and cannot know from unconstrained inversion of regional magnetic field data

Presenter: Clive Foss / CSIRO Mineral Resources

Date and time: 4pm (AEST time), 27th Sep 2023



For many years regional magnetic field data acquired by Geoscience Australia and State and Territory geological surveys has enabled and transformed geological mapping across Australia where many areas are beneath extensive cover and/or pervasive deep weathering. As computing power and availability have increased by orders of magnitude the same data that so successfully supports geological mapping is being re-purposed for building continuous three-dimensional magnetisation models. These models are in some cases accepted by their users in confidence that they are true representations of the subsurface achieved by spectacular powers of computing. However, while aeromagnetic surveys perform extremely well in mapping the horizontal locations and extents of magnetisations, recovery of models of subsurface magnetisation is severely restricted by extensive non-uniqueness. Magnetic field data is so useful for geological mapping because of the dominant expression of shallow magnetisations, in many cases directly beneath a basement unconformity. The sharp curvature of these field variations carries all the reliable information in the magnetic field data. Deeper magnetisations may cause the bulk of amplitude changes in the magnetic field without giving rise to diagnostic curvature of the field. These parts of the magnetisation cannot be reliably assigned to a specific depth or depth range. In space-filling voxel inversions this task is achieved by depth-weighting functions included in the inversion algorithms. It is these functions, not the distribution of magnetisation in the ground, that determine the depth distribution of magnetisation in the models.

I propose separation of features of sharp curvature that carry the most reliable source information (that I term ‘sweet spots’) from the remaining, much less informative field variations. This results in subsurface models that are much sparser in their apparent level of detail. It may seem a negative message, but it is not, because the distilled information can be treated with much higher confidence than continuous models in which it is not clear which aspects can be trusted and which cannot. I use examples of Australian regional magnetic field data to demonstrate analysis and interpretation of sweet-spots suitable for estimation of depth to magnetisation and sweet-spots suitable for estimation of magnetisation direction.      


Clive is a senior principal research scientist in CSIRO Mineral Resources where he works mostly on magnetic field inversion and interpretation. He has a BSc and PhD from two Earth Science departments where he learnt to integrate studies of physics and geology. His particular interest since his PhD (a long time ago) on Archean rocks of Southern Africa is in the magnetic field expression of remanent magnetisation and how direction of magnetisation can be recovered from magnetic field data. After his PhD Clive taught exploration geophysics at the University of Malaya in Kuala Lumpur where living between the geographic and magnetic equators provoked an interest in low inclination magnetic fields. Clive then moved to Bandung to work for the Bureau of Mineral Resources (BMR, now Geoscience Australia) on the AIDAB funded Indonesia – Australia Geological Mapping Project in Kalimantan. Following that Clive returned to Kuala Lumpur to work as a consultant and for ARK Geophysics based in Kuala Lumpur providing services in gravity and magnetic methods for petroleum companies throughout Southeast Asia. In 1995 Clive moved to Sydney, Australia to work with Encom Technology both contributing to the ModelVision development team and acting as senior consultant on gravity and magnetic projects worldwide. In 2009 Clive moved to his present position in CSIRO. 

SEG Distinguished Instructor Short Course (DISC) - Distributed acoustic sensing for seismic measurements – what geophysicists and engineers need to know

Tuesday, September 12, 2023

We are delighted to share with you the details for an upcoming SEG Distinguished Instructor Short Course (DISC) being hosted by the ASEG. 

This course will be run virtually over two days. 


Who: Dr Mark E Willis, Chief Scientific Advisor of Borehole Seismics at Halliburton

What: Distributed acoustic sensing for seismic measurements – what geophysicists and engineers need to know - DISC course

Where: Virtually. There will be a streaming of the virtual course in Brisbane at Anglo-American office, Brisbane, QLD. Please contact if you would like to join the streaming (ensuring that you also register for the virtual DISC)

When: September 12th and 13th 2023, 9am - 1pm ACST each day. 

Cost: $250 USD for SEG and ASEG members which includes access to software and a copy of the accompanying e-book. ASEG members need to use the code emailed to them, or contact Registration cost for non-members is $375 USD.

Register: Please register here by September 12th.


Course description: Geoscientists and engineers are very comfortable using seismic data sets acquired with geophones, hydrophones, and accelerometers because we have a long, well-defined set of standards for acquiring, processing, and interpreting them. However, distributed acoustic sensing (DAS) seismic measurements are rapidly augmenting, and in some cases replacing, the data from these conventional tools. Technologists are frequently unaccustomed to using DAS seismic data sets since it directly acquires relative strain or strain rate measurements and not the more familiar pressure, displacement, velocity, and acceleration data. There are also acquisition parameter selections that must be made to optimize the acquired data to accomplish the purpose of the seismic survey. This course is designed to build an intuition and understanding of the value, limitations, and applications of DAS seismic technology. In addition to the lecture and accompanying book, software will be provided, which will allow the student to interactively explore DAS seismic technology.


For more details visit Current DISC - SEG.

ACT Tech Talk: Scalable Streamlining of Ambient Noise Tomography: A Simple Automated Approach for Dispersion Curve Estimation and Quality Control in the Era of Big Data

Thursday, July 20, 2023

Title: Scalable Streamlining of Ambient Noise Tomography: A Simple Automated Approach for Dispersion Curve Estimation and Quality Control in the Era of Big Data

Speaker: Babak Hejrani

Date/Time: Jul 20, 2023 16:00


Babak Hejrani is a seismologist specializing in the field of geophysics within GA's Onshore Seismic and Magnetotelluric Section. With a decade-long background as a researcher in academia, Babak joined GA in 2018 and has since made contributions to developing new technologies for passive seismic imaging. He has established fruitful collaborations with international organizations in Europe, Asia and Australia with a primary focus around developing and implementing advanced imaging technologies that provide enhanced insights into the lithospheric structure of Australia. Babak strives to push the boundaries of seismic imaging, enabling more accurate interpretations of subsurface features.

Teams meeting:

Microsoft Teams meeting
Join on your computer, mobile app or room device
Meeting ID: 429 910 034 185
Passcode: jbC4ve
Or call in (audio only)
+61 2 8318 0003,,834313932#   Australia, Sydney
Phone Conference ID: 834 313 932#

ACT tech talk: Continental-scale multilayered chronostratigraphic interpretation of airborne electromagnetics

Wednesday, May 24, 2023

Title: Continental-scale multilayered chronostratigraphic interpretation of airborne electromagnetics

Presenter: Sebastian Wong

Date and time:  4pm (AEST time) on 24th May

Virtual attendees: Click here to join the meeting (Microsoft Teams) (Or call in (audio only) +61 2 8318 0003,,134611687# ) 


Induced Polarization effects in Electromagnetic data: opportunity or waste of time?

Thursday, March 30, 2023
1645 (ACT)
1745 (ACT)

Title: Induced Polarization effects in Electromagnetic data: opportunity or waste of time?

Speaker: Francesco Dauti, PhD student at University La Statale of Milan

Date/Time: 30/03/2023 @ 1645

Zoom Registration:


The possibility to model the Induced Polarization (IP) effects from the time-domain Airborne Electromagnetic (TD-AEM) data has gained considerable interest in the last two decades from both industry and academia. 

Recently, it has been physically demonstrated that IP effects can distort AEM data that, if not recognized and properly treated, can lead to artefacts in the modelled resistivities.   What it is still unclear though is if these distortions can be robustly recovered and modelled, providing useful information on polarisation effects within the ground.

Results on two aspects of airborne IP (AIP) modelling will be discussed:

(i) if modelled AIP effects can give significant information for exploration, and

(ii) if it is possible to measure and model AIP in AEM fixed-wing systems.

Francesco Dauti is a Ph.D. student in exploration geophysics at University La Statale of Milan. He took a bachelor’s and a master’s degree at University of Pisa, in geological sciences and in exploration and applied geophysics. His current research field is about the integration of galvanic and inductive Induced Polarization techniques for mineral exploration, both in terms of modelling, inversion, and interpretation.



Francesco Dauti is a Ph.D. student in exploration geophysics at University La Statale of Milan. He took a bachelor’s and a master’s degree at University of Pisa, in geological sciences and in exploration and applied geophysics. His current research field is about the integration of galvanic and inductive Induced Polarization techniques for mineral exploration, both in terms of modelling, inversion, and interpretation.

AuScope Special Seminar with ChEESE Program Leader Prof Arnau Folch

Monday, February 6, 2023
1200 AEDT
1330 AEDT

HPC is increasingly being used in solid Earth Geophysics in Europe and AuScope has organised this Special Seminar with Arnau Folch, leader of the EU ChEESE Program

ChEESE is the EU Centre of Excellence for Exascale in Solid Earth and develops translational research capabilities in High Performance Computing to the Exascale in geophysics, enabling multiscale, multiphysics and multi-hazard analysis.

In this seminar, Arnau will present the results of ChEESE-1P Exascale Pilot Demonstrators, including:

·  Rapid probabilistic forecasts of tsunami inundations; 

·  Earthquake source prediction; and

·  The atmospheric volcanic ash dispersal models validated in real time against high-resolution geostationary satellite data.

And, introduce ChEESE-2P and highlight its role in an ecosystem of projects that are shaping Europe’s Digital Future, including:

·  A Digital Twin for GEOphysical Extremes (DT-GEO);

·  Destination Earth (DestinE); and 

·  European Plate Observing System (EPOS)

Date: February 6th from 12 pm to 1:30 pm AEST.

Please register here via Eventbrite.



The first phase (ChEESE-1P) ran from 2018-2022 and addressed scientific and technical computational challenges in moving existing systems to Exascale in seismology, tsunami science, volcanology, and magnetohydrodynamics. ChEESE-1P initiated the optimisation of 10 Community flagship European codes for the European pre-Exascale and Exascale supercomputers and developed 12 Pilot Demonstrators (PD) that enabled services oriented to critical aspects of geohazards, including hazard assessment, urgent computing, and early warning forecasting.

Following the success of ChEESE-1P, a second 4-year phase (ChEESE-2P) with funding of € 7.8 million was launched in January 2023. Arnau will lead a team of Earth and Computer Scientists across multiple programs that will further develop the ChEESE-1P codes and new codes in geodynamics and glaciology.

We are delighted to be hosting Arnau and welcome you to join us in what will surely be a great seminar.

Is there a seismic refraction signature for sulphide mineralisation?

Wednesday, October 19, 2022

On Tuesday 19th October, 6:00pm AEDT, ASEG NSW is bringing you a talk by Derecke Palmer (UNSW) titled Is there a seismic refraction signature for sulphide mineralisation?

Although I accepted retirement from UNSW almost two decades ago, I have continued with my longstanding research interests in near surface refraction seismology. The major theme of my research has been full trace processing. Inexorably, full trace processing leads into detailed model building with traveltimes and amplitudes. My presentation addresses three important questions.

The first is “Is there a seismic refraction signature for sulphide mineralisation at the base of the regolith?” The second is: “Will full waveform elastic inversion rapidly replace traveltime acoustic tomographic inversion, and become routine with most geotechnical investigations?” The third is: “Would a detailed analysis of the refraction component of selected regional reflection profiles recorded by GA be useful?” The presentation employs seismic data recorded by GA near a major operational gold mine.

Attendance is by joint Zoom virtual + physical presentation at Geoscience Australia.

Register Here:

Please bring your own drinks and nibbles if attending online.

NExUS - Geological Interpretation of Aeromagnetic Data – a Practical Approach

Tuesday, August 2, 2022

Geological Interpretation of Aeromagnetic Data – a Practical Approach

2-Day Online Workshop, 1st – 2nd August 2022

(Limited to 30 places)


NExUS-Professional Development (NExUS-PD) is proud to be able to present this very highly regarded workshop online for the very first time.
• The specially designed two-day online workshop* will introduce the fundamentals of geological interpretation of aeromagnetic data.
• The workshop will feature lectures, practical activities and case studies all using integrated data sets.
• Each day will feature 3 x 2hr sessions with exercises to be completed between the sessions and time allocated for extended discussions.
• The format aims for open, transparent communication, with input from participants highly encouraged to share knowledge and experiences.
*This is a level-4 course (honours level) and is designed to be suitable for early career geoscientists, honours students and HDR students. The workshop is not assessed.


Day 1, Methodology of Aeromagnetic Interpretation – David Isles (1st Aug) :
• Sessions will include: Basic Principles, Physics and Concepts of Magnetics, Spatial Concepts, Survey Planning, Processing and Presentation of Data, Anomalies, RTP and Analytical Signal, Modelling and Inversion, Introduction to Golden Dyke Prospect Case Study
Day 2, Geological Interpretation and Structure – Leigh Rankin (2nd Aug) :
• Sessions will include: Golden Dyke Prospect Case Study, Magnetisation in Rocks, Charters Towers Case Study, Structures in Magnetics, Widgiemooltha Case Study, Unusual Magnetisation and Final Q+A session.

To Register, click here. 

Full Registration: $500

AIG and ASEG Members: $400

Students: $50

For further information view this flyer or, please contact: