KEGS February Talk
Our next KEGS talk is happening on February 14th at 4:00 PM. The talk will be hosted online.
Title: Introducing Geonics EM38-4 for environmental studies and geophysical explorations
Speaker: Farzad Shirzaditabar
Authors: Farzad Shirzaditabar, Richard Heck, and Mike Catalano
Date: Tuesday February 14th at 4:00 PM
Location: Online. Register for the virtual session below:
Abstract: Geonics Ltd. has recently designed and manufactured EM38-4; a new version of the most popular handheld electromagnetic (EM) instrument EM38. This new instrument has one transmitter and four receiver coils at distances of 0.5, 0.75, 0.88 and 1 m apart from transmitter. Transmitter coil is energized by an alternating electric current of 14.5 kHz and produces an alternating primary electromagnetic field. The magnetic component of this EM field penetrates to the subsurface and induces electric currents in it. These currents are proportional to electrical conductivity (EC) and magnetic susceptibility (MS) of the subsurface materials. All receivers have the ability to sense, simultaneously, in-phase and out of phase components of secondary magnetic field created by the induced currents. The instrument is connected to a tablet, which works in windows operating system and has a built-in GPS, via a cable where the data and position of each data point are recorded together. Although there are manual adjusting knobs on the instrument, calibration of all receivers can be automatically done using an appropriate software when the instrument is placed on a monopod 1.5 m above surface. Since the transmitter-receiver separations in EM38-4 are much less than skin depth of the electromagnetic wave of the transmitter, the in-phase and out of phase components are directly proportional to MS and EC of subsurface materials. Each receiver has also its own depth of penetration. So, the instrument can reveal apparent MS and EC of the ground under the measuring point at four different depths. This feature makes the instrument a proper and efficient tool for environmental and agricultural studies as well as archaeological and even near surface geophysical explorations. Inversion of recorded data are also possible where details of the subsurface are required.
We had the chance to borrow the instrument from Geonics Ltd., in September 2022 and test it over an agricultural land, located at Haldimand County in southern Ontario, to map variations of both MS and EC of soil by depth. Plotting the maps of measured MS and EC revealed a depressional area having high EC and low MS at all receivers. We also inverted the data using nonlinear Occam’s inversion method to calculate EC and MS variations with depth. Results of inverting the data showed that EM38-4 is more sensitive to EC than MS of materials under the instrument.
Upcoming KEGS talks and events
KEGS is pleased to announce a list of confirmed talks and events going forward:
March 4th, 2023: KEGS PDAC Symposium
KEGS is currently looking for speakers for the Fall 2023 meetings. If you are interested to speak at a KEGS monthly talk, please contact any of the Executive.
Find out about more geoscientific events in GTA Geoscience calendar here.
KEGS PDAC Symposium Registration is OPEN
The KEGS Symposium is back, in person, on March 4th, 2023 - the Saturday preceding the 2023 Prospectors and Developers Association of Canada (PDAC) Convention in Toronto, Canada. This is our first, full-length, in-person symposium held in three years! The preliminary program can be downloaded below. A reception will follow the days talks.
When: Saturday, March 4, 2023
Where: InterContinental Hotel, 225 Front St W, Toronto, ON M5V 2X3.
$300.00 CAD for Members
$375.00 CAD for Non-Members
$50.00 CAD for Students
Registration includes breakfast, coffee, lunch and one drink ticket at the reception.
KEGS Executives extend their condolences to the family, friends and colleagues of Dr. Yves Lamontange. President of Lamontagne Geophysics, an important innovator in ground EM and BHEM instrumentation and applications that enabled (inter alia) discovery of multiple deep Ni-Cu deposits in the Sudbury camp. Yves was also a founding Director of the KEGS Foundation and a very generous sustaining supporter. Various tributes and memorials are in preparation or being actively considered by former colleagues. They will begin with a talk on UTEM and its history by Bruce McMonnies of Lamontagne Geophysics at Queen’s University, on February 8 at 2:30 pm in Miller Hall, which will also be livestreamed, and can be accessed via the link below.
UTEM and its History
2023 J. Tuzo Wilson Lecture
Please join us for this exciting lecture, celebrate the distinguished contributions and achievements by the late Prof. J. Tuzo Wilson, and meet old/new friends in-person (after 3.5 years). Refreshments will be provided after the lecture. Further Information here.
Title: 2022-2023 J. Tuzo Wilson Lecture: Carbon Capture and Sequestration: Panacea or Indulgence?
Date/Time:Feb 28 2023, 7:30-9 pm (also live-streamed)
Location: Isabel Bader Theatre, Victoria University
Speaker: Prof. Roel Snieder (W.M. Keck Distinguished Chair of Professional Development Education at CSM)
Affiliations: Colorado School of Mines
Abstract: Current events show that climate change is upon us. The mechanism of global warming was already explained fairly accurately by Arrhenius in 1896. An alternative to reducing greenhouse gas emissions by burning less fossil fuels is to capture CO2 and then store it in the subsurface. This technology relies on our expertise in injecting fluids in the subsurface and to monitor the fluids and their fate in the subsurface. This technology has been presented as "a well-accepted leading mitigation strategy against climate change.” In order to understand to what extent this optimism is warranted one needs to consider the following factors: (1) the amount of CO2 that needs to be captured and sequestered to have a significant impact on climate change, (2) the cost of CO2 capture and sequestration compared with other technologies for avoiding CO2 emissions, (3) the reason why CO2 capture is expensive and energy-intensive, and (4) the extreme accuracy with which CO2 in the subsurface needs to be monitored. As with many complicated problems, the devil is in the details, and we need to understand these details to assess the impact of carbon capture and storage that can be expected. This determines whether this technology is a panacea or an indulgence.
Seequent: Airborne Magnetic Levelling & QC Workshop - In-Person - PDAC March 2023
New to airborne magnetic quality control and levelling or just looking for a refresher? Join us in this workshop to learn a comprehensive workflow for quality control and levelling of airborne magnetic geophysical survey data in Oasis montaj.
Registration includes complimentary access to everything you need for the course, including Oasis montaj, Geophysics, Airborne QC and Levelling. Further information here.
Don't forget to renew your KEGS membership for 2023! The membership costs remains unchanged at $50 + HST for regular members and $25 + HST for students. While at it, why not consider a donation the KEGS Foundation to help foster and support geophysical education at Canadian Universities. Renew your membership here. We thank you for your continued support.
KEGS Foundation Update
Additional details can be on the Foundation’s website.