April 2024 Monthly Talk

Speaker:Martyn Unsworth
University of Alberta
2023-2024 CSEG Distinguished Lecturer
Title:Magnetotellurics: Using natural radio waves to look inside the earth
Date:Thursday, April 4, 2024
Time:4:30pm to 5:30pm PDT
Location: Room 111 – 409 Granville Street
Vancouver, BC, V6C 1T2

Flyer

Unsworth CSEG DL Flyer 2023-2024

Abstract

Geophysical exploration provides important information for resource exploration, studies of geohazards, and investigations into how the Earth works. Seismic exploration is the most widely used geophysical technique and is an invaluable tool for oil and gas exploration. However, no single geophysical technique can answer all questions about Earth structure. An alternative method uses low-frequency electromagnetic (EM) signals to image the electrical resistivity of the Earth. This rock property is sensitive to the presence of fluids and a number of economically important minerals. For more than a century, EM techniques have been applied in areas including hydrogeology, mineral exploration, and geothermal energy development. EM methods focused on near-surface exploration utilize signals generated with a transmitter. For deeper exploration it is most efficient to use magnetotellurics (MT) – an EM method that uses natural EM signals to image subsurface structure. In this lecture, I will describe the physics of the MT method and outline its range of applications. This lecture will emphasize (1) how MT is now capable of working in 3-D to develop realistic models of subsurface resistivity (2) how MT is most effective when used in combination with other geophysical methods, and (3) introduce applications of societal relevance including include mineral exploration, volcanology, geothermal exploration, and tectonic studies.

Bio

Professor Martyn Unsworth is a faculty member in the Department of Physics / Earth and Atmospheric Sciences at the University of Alberta. His research focuses on the development of electromagnetic methods in geophysics. Applications in applied geophysics includes studies in mineral exploration, geothermal energy development and imaging permafrost. He has also used magnetotellurics extensively in investigations of plate tectonics, earthquake hazards and volcanoes. He received a BA in Natural Sciences (1986) and a PhD in Marine Geophysics (1991), both from the University of Cambridge. His postdoctoral research at UBC was focussed on the development of inversion methods for controlled source electromagnetic data. After working as a Research Professor at the University of Washington in Seattle, he joined the geophysics group at the University of Alberta in 2000.

BCGS Roundup Breakfast 2024

Speaker:Darren Burrows, BSc (Hons)
Senior Geophysicist, Fleet Space Technologies
Title:Exploring the Earth, Moon and Mars with Modern Geophysical Sensors
Date:Tuesday, January 23, 2024
Time:7:30am – 9:30am PST
Location:Pan Pacific Vancouver Hotel
Oceanview Suite 1-2
300 – 999 Canada Place
Vancouver, BC, V6C 3B5
Registration:Industry $50 / Student $20*

* Note: Student registration fees will be refunded following the breakfast. This has been made possible by generous sponsorship from Condor Consulting Inc.

Please register and pay via Paypal at the link below.
Registration will close on Fri, Jan 19 @ 12pm. Space is limited so register early!

Thank you to everyone for their support!
We have reached capacity and the breakfast is now sold out!


Abstract:

Exploring the Earth, Moon and Mars with Modern Geophysical Sensors
Darren Burrows, BSc (Hons), Fleet Space Technologies

Fleet Space Technologies is a leading Australian space exploration company with a mission to connect and explore the Earth, Moon, and Mars. We will begin this discussion by walking through our journey of designing, building, launching and operating Australia’s first commercial LEO nanosatellite constellation and how we are approaching its expansion. By using a combination of satellite communications, our purposefully designed geophysical sensors, and cutting edge software we are helping to accelerate mineral exploration on Earth. Next we move to our closest neighbour, the Moon, where Fleet will be deploying the Seismic Payload for Interplanetary Discovery, Exploration and Research (SPIDER) to collect seismic data from the lunar surface as part of NASA’s Commercial Lunar Payload Services (CLPS) initiative in 2026. The SPIDER design and testing process will be discussed, as well as our ideas on large scale lunar exploration. Lastly, we will share our ideas on how resource exploration will allow humans to build permanent bases on Mars.

About the Speaker:

Darren graduated from the University of the Witwatersrand in Johannesburg, South Africa with a Geophysics (Hons) degree. Initially he worked in deep Gold mines analysing mining induced seismicity, to ensure safe underground mining conditions. He then moved to Platinum exploration in the Bushveld Igneous Complex planning drillholes, logging core and managing exploration data. A large part of his career was spent in airborne geophysics with Fugro / CGG / Xcalibur where he has held various roles focusing on geophysical data processing & interpretation as well as business development. At Fleet Space Technologies he entered the emerging field of ambient noise tomography and applies it to solve mineral exploration problems.

2023 Annual General Meeting

Our 2023 annual general meeting (AGM) will be held:

at 4:30pm on Tuesday, December 12, 2023
at Moose’s Down Under, Basement 830 West Pender St., Vancouver BC. V6C 1J8

The main order of business will be to elect the Directors of the BCGS and review the past year’s activity. Our bylaws allow for between 4 and 7 Directors. The current directors are standing for re-election.

We are inviting interested persons to nominate themselves for election to join the Board of the BCGS. Please indicate your intent to do so by 23h59 on Thursday, December 7, 2023.  All names of prospective candidates will then be included on a revised AGM notice to be emailed out the following business day if any changes are required.

The BCGS directors standing for re-election are:

Chair / TreasurerRoss PolutnikSJ Geophysics Ltd.
Vice-ChairKyle PattersonConvolutions Geoscience
Scholarship CoordinatorFrancis JonesUBC
Technology SpecialistDominique FournierMira Geoscience Ltd.
DirectorGriff JonesGolder Associates
DirectorShawn LettsAnglo American Ltd.

We would like to remind you there are two classes of voting members in the BCGS:

  1. General members. An annual fee of $20. Will be returned as a discount should they choose to enroll in our annual symposium; and
  2. Student members. Free membership upon demonstration of enrollment in a post-secondary program at an accredited educational institution.

In order to participate in the vote, we ask that you pay your 2024 member dues online via Paypal on the “Join Us” page (link below). These member dues will provide membership in the BCGS through 2024. Eligible students, as defined above, are entitled to vote. If you are unsure of your current membership status please send us an email (info at bcgsonline.org) and we’d be happy to check for you.

http://www.bcgsonline.org/join-us/

The AGM is open to all members and non-members.

August 2023 – Monthly Talk

Speaker: Brendan Howe, Teck Resources Limited

Title: An Empirical Geophysical Model for Porphyry Copper Deposits in the Laramide Copper Province

Date: Thurs, August 24, 2023

Time: 4:30pm to 5:30pm PDT

Location: Room 111 – 409 Granville Street, Vancouver, BC, V6C 1T2

Abstract:

The Laramide copper province is located in southwestern North America, covering parts of Arizona, New Mexico, and Texas in the U.S, in addition to Sonora, Chihuahua, Sinaloa and Baja California in Mexico. Porphyry copper mineralization is associated with Laramide age (~80-45 Ma) magmatism and has been estimated to represent ~300 million tonnes of copper metal, making it a globally significant accumulation of the red metal. The geological and geochemical manifestation of these mineralizing systems have been well documented. Specifically, exploration models based on alteration zonation and trace element geochemistry have been developed and successfully deployed in the province since the late 1960’s. As a result of post Laramide extension and deposition, much of the province is covered by post-mineral rocks or sediments, and it can be argued that the greatest residual potential for future discoveries is located within the covered regions. Consequently, geophysical datasets are playing a more prominent role in integrated targeting of porphyry systems. In this extended abstract, we present a series of observations and interpretations of geophysical data from various deposits in the province with the goal of developing an empirical model to guide selection of geophysical method, interpret subsequent results and ultimately contribute to future exploration success.

Bio:

Brendan Howe is the Technical Manager of Exploration at Teck Resources. Prior to joining Teck he worked for Barrick Gold as a Senior Geophysicist. He completed a combined BSc. / B.Comm in Geology-Finance from the Australian National University. Brendan is a past chair of the BC Geophysical Society.

Webinar:

Late May 2023 – Monthly Talk

Speaker: Peter Fullagar, Fullagar Geophysics Pty Ltd.

Title: Beyond Plates – fast TEM inversion using conductive ellipsoides

Date: Thursday, May 25, 2023

Time: 4:30pm to 5:30pm PDT

Location: Room 111 – 409 Granville Street, Vancouver, BC, V6C 1T2

Abstract:

Interpreting TEM anomalies in terms of conductive rectangular plates is effective in many situations. However, not all conductors are thin and planar. Triaxial ellipsoid conductors represent an attractive alternative: geometrically simple (corner-free), mathematically tractable at early and late time limits, and able to encompass shapes ranging from poddy to tabular to lensoidal to elongate. Accordingly a fast  magnetostatics-based algorithm has been developed to compute ellipsoidal conductor responses in both resistive and inductive limits. Focusing on TEM data close to the resistive or inductive limit is attractive not only because it simplifies both the physics and the computations, but also because in many cases the late time or early time response is of particular interest in mineral exploration. Inversion of measured data entails adjustment of selected ellipsoid parameters, subject to user-imposed upper and lower bounds. The methodology is suitable for downhole, ground, or airborne TEM, either impulse or step response. In this presentation the conductive ellipsoid forward and inverse algorithms are briefly described and illustrated via application to TEM field data.

Bio:

Peter Fullagar holds a PhD in geophysics from UBC. He has over 40 years experience in base metal and precious metal exploration, and in metalliferous and coal mining geophysics. He worked for a total of 14 years with Western Mining Corporation (WMC) and Rio Tinto in Australia. Peter has also held academic and research positions, at Ecole Polytechnique in Montreal and with CSIRO Exploration & Mining in Brisbane. Since his tenure as Chief Geophysicist for WMC in the early 1990s he has promoted utilisation of geophysics in operating mines. He established Fullagar Geophysics Pty Ltd in Brisbane in 1998 and has consulted privately for the past 25 years. During that time he has developed geophysical modeling and inversion software, mostly for EM, potential fields and borehole logging, with a focus on integrated interpretation of geophysics and geology. He has also supervised several MSc and PhD students, and has taught undergraduate courses in potential fields, and electrical and EM methods, at the University of Queensland. He is currently based in Noosa, Queensland.

Webinar: