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TAS

TAS tech talk - Insights into the 2018 eruption of Kilauea Volcano from ambient seismic noise and the application of seismic noise for imaging and monitoring in mines.

Thursday, February 27, 2020
1730
1900

On Thursday 27 February, Dr Gerrit Olivier will present Insights into the 2018 eruption of Kilauea Volcano from ambient seismic noise and the application of seismic noise for imaging and monitoring in mines.  This is a joint meeting with the Tasmanian branch of the GSA.  As ever, it will be preceded by drinks and nibbles at 5:30 pm in the Earth Science tea room (upstairs from the main entrance), with the main event following at 6 pm in the lecture theatre (back downstairs).  Gerrit’s abstract is also attached.

Gerrit obtained his PhD in Geophysics from the University Grenoble Alpes in France after completing an MSc and BSc in Theoretical Physics at the University of Stellenbosch in South Africa. He is currently a Director and heads up the Applied Geophysics group at the Institute of Mine Seismology – the world’s leading provider of seismic monitoring technologies for mines. He also serves as a Senior Adjunct Researcher at the University of Tasmania and and an Associate Researcher at University Grenoble Alpes in France. He has received awards from the American Geophysical Union and the Institution of Civil Engineers for his research in applying seismic noise interferometry to monitor and image underground mines and tailings dams.

Abstract:

Insights in to the 2018 eruption of Kilauea Volcano from ambient seismic noise and the
application of seismic noise for imaging and monitoring in mines

Ambient seismic noise interferometry is a method that enables seismologists to extract useful
information from faint background seismic noise. The method can be used to image the
subsurface with high resolution and/or monitor time-lapse changes in seismic velocity with
high accuracy in nearly any environment, without the need for active sources or earthquakes.
In this presentation, I will show how applying seismic noise interferometry has helped us
gain valuable insights in to 2018 eruption of Kilauea volcano. The 2018 Kilauea eruption was
a complex event that included deformation and eruption at the summit and along the East Rift
Zone. The eruption lasted three months and emitted around 800 million cubic meters of lava,
destroying more than 700 homes in the process. We used ambient seismic noise
interferometry to measure time-lapse changes in seismic velocity of the volcanic edifice prior
to the eruption. Our results show that 10 days before the eruption, there is a clear change in
the response of the seismic velocities to applied pressure. We also applied ambient seismic
noise tomography to image the state of the volcano after the eruption. The results of this
study will have implications for forecasting volcanic eruptions and our understanding of the
behaviour of volcanoes leading up to major eruptions. Finally, I show how the methods we
applied to Kilauea volcano are currently being used by the Institute of Mine Seismology to
monitor underground mines and tailings dams, while also being used as a cost effective and
environmentally friendly method for mineral exploration.

TAS tech talk - How the Canadian Metal Earth project strives to improve our knowledge of mineralization: an overview of multidisciplinary geophysical methods.

Tuesday, February 25, 2020
1300
1500

Just before he leaves us for the second time, Dr Esmaeil Eshaghi will tell us of How the Canadian Metal Earth project strives to improve our knowledge of mineralization: an overview of multidisciplinary geophysical methods.  Esi’s insider perspective of this huge effort getting underway to improve Canadian discovery rates will be at 1300 on Tuesday 25 February in the CODES conference room (UTas Sandy Bay).  An abstract is attached.  Members are invited to join the speaker and president for lunch at the Uni Staff Club afterwards.  Please RSVP to me or Matt Cracknell (tassecretary@aseg.org.au) if you’d like to come.

As many of you will well remember, Esi was in the airborne geophysics group at the Geological Survey of Iran before completing his PhD in regional potential field modelling at UTas a few years ago and proceeding to a postdoc stint at Laurentian University in Sudbury.  Currently he is with Thomson Aviation as a geophysicist.

Abstract:

How the Canadian Metal Earth project strives to improve our knowledge of mineralization:
an overview of multidisciplinary geophysical methods

Since 2005, there was a marked increase of costs to explore new economical mineral occurrences,
while the success of discovery of new deposits has diminished. Metal Earth, led by the Mineral
Exploration Research Centre at the Harquail School of Earth Sciences, Laurentian University,
Canada, is a seven-year $104 million applied research project with the main goal of improving the
understanding of mineral endowment in Precambrian greenstone belts. An essential part of this
project is to use geological observations and geophysical data to define crust to mantle scale
differences between transects that cross metal endowed and lesser endowed Archean greenstone
belts to define key mechanisms responsible for the genesis of base and precious metal deposits.
For this purpose, high resolution datasets are acquired and combined with existing data to create a
multidisciplinary database containing different geological and geophysical information (e.g.
geological observations, targeted mapping, seismic, gravity, magnetic survey, electromagnetic,
and petrophysics).
In this talk, I preview multidisciplinary geophysical data acquisition, processing and initial models
across different transects, both minerally enriched and less endowed, and provide an overview of
findings so far. It includes a brief discussion of seismic, magnetotelluric and potential field data
(i.e. gravity and magnetic) data and models along some transects as well as petrophysical
characterisations within Abitibi Greenstone Belt. The initial models indicate some distinct
differences between minerally prospective and less-prospective areas at depth. The findings are
promising in terms of identifying new components contributing to mineral deposition.

Tasmania Geoscience Forum

Thursday, December 5, 2019
0900
2200

Seminar Overview

The AusIMM Tasmania Branch, GSA, IAG and Tasmanian Government are pleased to bring you the Geoscience Forum.

The purpose of this forum is to assemble Geoscientists in one pleasant place to share their progress in exploration, mining and research.

This event is for sharing results and ideas in the geosciences and learning more about geology, in particular the geology of Tasmania.

Field Trip Friday, 6 December 2019

A field trip is planned the day after the Forum to visit historic and geological sites of interest in north east Tasmania.

Further details will be available shortly.

Accommodation

Delegates will need to book their own accommodation with the venue (Tidal Waters Resort) or at a venue of their choice.

Expressions of Interest for Guest Speakers

Please contact the Tasmanian Branch if you have any suggestions for speakers.

Sponsorship Opportunities

We welcome sponsors to assist in this event. Display tables will be available at the venue.

Contact the Tasmanian Branch to become a sponsor.

Registration details available here: https://ausimm.com/news/registrations-now-open-tasmania-branch-geoscienc...

TAS - AGS Workshop on InSAR and its Application for Understanding Ground Movement

Wednesday, February 12, 2020
0800
1900

AGS Tasmania Radar Interferometry Workshop

Registrations now open: AGS Workshop on INSAR and its Applications for Understanding Ground Movement

Radar interferometry (InSAR) is a rapidly expanding technique that offers valuable insight into ground deformation for a range of applications, particularly in the field of geotechnics. Due to advancing radar technology and increasing numbers of satellites, the quality and frequency of spaceborne radar coverage available for InSAR is continually improving. An increasing range of radar datasets are becoming freely available, further increasing application potential in geotechnical studies of various scale. However, InSAR is a technically complex technology necessitating appropriate planning, processing, and interpretation. This workshop is aimed at providing end-users and those commissioning imagery a basic understanding of the technique and its limitations in order to improve success and avoid disappointment. Those interested in conducting their own processing using commercially available software require further theoretical and applied background that is beyond the scope of this workshop.

Presenters

Dr. Bernhard Rabus is a Professor in the School of Engineering Science, Simon Fraser University, Canada. He has a geophysics background and is an internationally recognised expert in InSAR technology and processing with numerous academic publications to his credit, plus prior experience in government and industry roles. He teaches graduate and undergraduate courses in synthetic aperture radar applications, including InSAR, and undertakes a range of radar-based research activities.

Dr. Nicholas Roberts is a natural hazards geologist in the Geological Survey Branch of Mineral Resources Tasmania. He has strong interests in landslides and Quaternary geology with a range of academic publications and previous industry and government roles. Nick is also an Adjunct Professor at Simon Fraser University and collaborates with Dr. Rabus as an end-user to apply InSAR to a range of geological applications in diverse settings, including Tasmania.

Registration now open

An expressions of interest process earlier this year indicated strong support for the workshop to the point that the course is theoretically at capacity. Registrations are now open with priority given to those who previously responded if they register within 1 month of this notice being issued. Others are welcome to apply immediately should any spaces be available once the priority period is finished.

Day 1 (12 February) – The basics:

Providing high-level understanding of InSAR and its applications for a range of ground deformation questions through key lecture topics. The session will be held in central Hobart starting at 8:30

Basic introduction to synthetic aperture radar and its differences from remote sensing techniques conventionally used in geotechnical investigations (e.g. aerial photography, optical satellite imagery, LiDAR).

Overview of various InSAR techniques, their processing chains, and their strengths and weaknesses for particular applications.

Case studies of InSAR applications for slope stability and ground subsidence including discussion of specific considerations relevant to particular project types (e.g. pit mine stability, ground subsidence, landslide mapping, urban geohazards).

Merits of outsourcing and in-house processing (e.g. what to ask for when commissioning third party providers; assessing tenders from third party providers; what skill sets and resources are required for in-house processing; what data formats to specify from your provider).

Analysing and integrating InSAR data with other spatial data sets in a GIS environment (interested parties can bring laptops with Google Earth and QGIS installed and do some basic hands-on exercises).

Day 2 (13 February) – One-day field exercise:

Relating features in the field with their representation in InSAR datasets and building on the understanding of InSAR’s utility for addressing geotechnical questions in various environments.

Field sites will include locations for which various radar data and, where possible, InSAR results are available.

Please note that the field exercise will involve short walks over uneven ground to various sites. You are strongly advised to bring warm clothing.

Day 3 (14 February) – Technicalities of InSAR:

Providing greater detail on the processing chain for various InSAR techniques as well as specifics of data selection and access.

This final, lecture-based component of the workshop targets more advanced users including those with interest in conducting their own InSAR processing. Activities and topics will include:

Defining geotechnical problems in a way your InSAR provider will understand.

Selecting suitable imagery and satellites in greater detail.

Processing methods in more detail.

Advanced quality assessment of delivered products.

Registration fees

Standard Member rates*

Day 1 – The basics of InSAR $AUD700

Day 2 – Field Exercise $AUD500

Day 3 – Technicalities of InSAR $AUD500

Note: a $250 loading on the total fee applies to those who are not AGS members

Members of the NZ Geotechnical Society will qualify for AGS member rates

Student discount negotiable on application.

For all questions regarding registration and payments please contact the Secretary. For all technical questions please contact Colin Mazengarb at colin.mazengarb@stategrowth.tas.gov.au

See details at AGS’s website ( https://australiangeomechanics.org/courses/ags-tasmania-radar-interferom...) for registration. 

TAS Tech talk - The development and implementation of drones for magnetic surveys

Wednesday, October 16, 2019
1200
1400

Dear ASEG Tasmania members and potential members,

Come and hear about Anton Rada’s work at the forefront of the development and implementation of drones for magnetic surveys.  Noon in the CODES Conference Room (UTas Sandy Bay campus), Wednesday 16th October.   Please let branch president Mark Duffett or branch secretary Matt Cracknell know if you’d like to join the speaker and Mark Duffett for lunch at the Uni Staff Club after the talk.

SEG Distinguished Lecturer Tour: Boris Gurevich

Wednesday, March 13, 2019
17:30
19:00

2019 Pacific South Honorary Lecturer Tour

Seismic attenuation, dispersion, and anisotropy in porous rocks: Mechanisms and Models
Boris Gurevich, Curtin University and CSIRO, Perth, Australia

Understanding and modeling of attenuation of elastic waves in fluid-saturated rocks is important for a range of geophysical technologies that utilize seismic, acoustic, or ultrasonic amplitudes. A major cause of elastic wave attenuation is viscous dissipation due to the flow of the pore fluid induced by the passing wave. Wave-induced fluid flow occurs as a passing wave creates local pressure gradients within the fluid phase and the resulting fluid flow is accompanied with internal friction until the pore pressure is equilibrated. The fluid flow can take place on various length scales: for example, from compliant fractures into the equant pores (so-called squirt flow), or between mesoscopic heterogeneities like fluid patches in partially saturated rocks. A common feature of these mechanisms is heterogeneity of the pore space, such as fractures, compliant grain contacts, or fluid patches. Using theoretical calculations and experimental data, we will explore how this heterogeneity affects attenuation, dispersion, and anisotropy of porous rocks. I will outline a consistent theoretical approach that quantifies these phenomena and discuss rigorous bounds for attenuation and dispersion.

Time table

Date State Venue Start time Contact
13 March WA Celtic Club, 2nd floor, 48 Ord Street, West Perth 18:00 Heather Tompkins
15 March ACT Geoscience Australia 12:30 James Goodwin
19 March Qld XXXX brewery (Alehouse), Black Street, Milton 17:30 Ron Palmer
20 March NSW 95-99 York St 18:00 Mark Lackie
21 March Vic The Kelvin Club 18:00 Seda Rouxel
25 March SA/NT Coopers Alehouse 18:00 Kate Robertson
27 March Tas Geology Lecture Theatre, University of Tasmania 13:00 Mark Duffett

Biography

Boris Gurevich has an MSc in geophysics from Moscow State University (1976) and a PhD from Institute of Geosystems, Moscow, Russia (1988), where he began his research career (1981–1994). In 1995–2000 he was a research scientist at the Geophysical Institute of Israel, where he focused mainly on diffraction imaging problems. Since 2001, he has been a professor of geophysics at Curtin University and advisor to CSIRO (Perth, Western Australia). At Curtin he has served as Head of Department of Exploration Geophysics (2010–2015) and since 2004 as director of the Curtin Reservoir Geophysics Consortium. He has served on editorial boards of Geophysics, Journal of Seismic Exploration, and Wave Motion. He is a Fellow of the Institute of Physics and has more than 100 journal publications in the areas of rock physics, poroelasticity, seismic theory, modeling, imaging, and monitoring of CO2 geosequestration. His research achievements include development of advanced theoretical models of seismic attenuation and dispersion in heterogeneous porous rocks.

Sponsors

Platinum sponsors
Gold sponsor

2018 SEG/AAPG Distinguished Lecturer: Satish Singh

Tuesday, August 7, 2018
17:30
19:00

Seismic Full Waveform Inversion for Fundamental Scientific and Industrial Problems.

Seismic waveform inversion is a powerful method used to quantify the elastic property of the subsurface. Although the development of seismic waveform inversion started in the early 1980s and was applied to solve scientific problems, it became popular in industry only about 15 years ago. One of the key elements in the success of seismic waveform inversion has been the increase of the acquisition of long offset seismic data from 3 km in the early 1990s to more than 15 km today. Not only did long offset data provide refraction arrivals, but it also allowed recording of wide-angle reflections, including critical angles, providing unique information about the subsurface geology.

In this talk, I will elaborate on the early development of the seismic full waveform inversion (FWI) and its application to solve fundamental scientific problems. The first big success of FWI was its application to gas hydrate reflections, also known as bottom simulating reflection (BSR), which showed that the
BSRs are mainly due the presence of a small amount of free methane gas, not a large amount of hydrates stored above the BSR, and hence the total amount of methane stored in marine sediments should be much less than previously estimated. A second major success of FWI was its application to quantify the characteristics of the axial melt lens observed beneath ocean spreading centers. The seismic full waveform inversion results show that one can distinguish between pure melt and partially molten mush within a 50 m thick melt lens, allowing to link the melt delivery from the mantle with the hydrothermal circulation on the seafloor. The application of full waveform inversion to spreading center problems has become an important area of research.

Unlike in sedimentary environment, the seafloor in general scientific environment could be very rough and water depth could be deep, making it very difficult to use the conventional method of background velocity estimation. To address this issue, the surface seismic data could be downward continued to the seafloor, as if both streamer and sources were placed on the seafloor, similar to land geometry. This method allows to bring the refraction starting from zero offset to far offset, which is extremely useful for full waveform inversion of first arrivals. The downward continuation also allows to reduce the seafloor diffraction, increase the moveout of reflection arrivals, and enhance wide-angle reflections, all important for seismic full waveform inversion. The application of a combination of downward continuation and FWI has allowed to quantify gas anomalies in sedimentary basins and fluids at subduction fronts. The waveform inversion also has been used to monitor CO 2 sequestration.

I will explain the intricacy of FWI, based on the physics of waves, specifically the role of amplitudes and converted waves in addressing fundamental scientific problems. The presentation should interest professionals working in the oil and gas sectors, or crustal studies and global seismology.

More details and biography.

Date City Address
30 July Brisbane  
1 August Canberra Scrivener Room, Geoscience Australia, CANBERRA
2 August Victoria Kelvin Club, 18-30 Melbourne Place, MELBOURNE
7 August Adelaide Coopers Alehouse, 316 Pulteney St ADELAIDE
8 August Sydney The University of Sydney
14 August Hobart CODES Conference Room, University of Tasmania, Sandy Bay
15 August Perth Ground Floor, 1 Ord St, WEST PERTH