BCGS Technical Talk – October 8, 2020

Speaker: Patrick Mah & Robert Perrin, DMT Geosciences

Title: An Integrated approach to Geophysics for near surface Engineering and Exploration Applications

Date/Time: Thursday, October 8, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

DMT Geosciences presents a case study where we successfully map a series of near-surface and deep features for a risk analysis project. An integrated approach that included a combination of airborne surveying, ground TDEM, and an extensive seismic reflection/refraction survey allowed us to identify features that would not be possible with a single system. The flexibility of the state-of-the-art SUMMIT X-1 seismic system enabled the field crew to optimize acquisition parameters in real time to ensure the near surface and deep survey objectives were satisfied. This approach can be applied to a variety of project types to reduce field acquisition time, improve overall data quality, and reduce project risk.

Webinar:

A recording of this webinar is available on Youtube.

BCGS Talk, Friday September 25, 2020

Speaker: Sergio Espinosa, Ph.D, SEGeoscience & Exploration

Title: Multivariate Statistical Risk Analysis during the COVID-19 Pandemic

Date/Time: Friday, September 25, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

“Multivariate Statistical Risk Analysis during the COVID-19 Pandemic”
Sergio Espinosa, Ph.D, SEGeoscience & Exploration

The risk of a disaster can be quantified with the probability  of occurrence of the catastrophic event within a time period (UNDRR).
This study examines the risk of death from COVID-19 of a healthy person during the on-going pandemic caused by the new coronavirus SARS-CoV-2.
 
In any Risk (R) assessment, e.g. earthquake-related, three elements are always  analyzed:

• Hazard (H)
• Exposure (E)
• Vulnerability (V)

Those three elements relate to Risk as follows: R = H + E + V

This means, the higher the Hazard level (H), the higher the  Exposure (E), and the higher the Vulnerability (V) of a  single person or of a community, the higher will be the Risk (R) of dying from the disease.

Furthermore, the probability of falling critically ill and from eventually dying from COVID-19 depends firstly on the  probability of getting infected. So, these two different risks, of firstly getting infected (R1) and of secondly dying (R2),  is described separately, starting with a single healthy non-infected person, called the susceptible host,  who is exposed to the new coronavirus SARS-CoV-2.

Bio:

Sergio studied Applied Geophysics at the School of Mines “Bergakademie” in Freiberg, Germany completing a BSc (Hauptstudium) in 1988 and a MSc (Diplom) in 1989. 

Besides being a mineral exploration geophysicist with almost 25 years of experience working for major and junior mining companies across various commodities, deposit styles and in diverse geological settings, Sergio has also a background in Seismology (PhD 1993, Freiberg, Germany), with also some training in Volcanology (e.g. Canary Islands) and Meteorology (FU Berlin), as well as a postdoc in Earthquake Hazards (1994/1995, GFZ Potsdam, Germany).

BCGS Technical Talk – August 27, 2020

Speaker: Jonathan Rudd, Dias Airborne

Title: Introducing two airborne systems with SQUID sensor technology

Date/Time: Thursday, August 27, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

Dias Airborne is introducing the QMAGT full tensor magnetic gradiometer (FTMG) system, and the QAMT passive EM system. These helicopter-borne systems are both built around low temperature SQUID sensor technologies that provide low-noise data acquisition. Ground-based low temperature and high temperature SQUID systems are well-established in mineral exploration industry, and their low noise advantage has brought significant benefits to many exploration programs. The QMAGT FTMG system is the product of over 20 years of research and development by the Supracon-IPHT and Anglo American – DeBeers groups. Anglo-DeBeers are operating this FTMG technology widely on their various exploration projects worldwide. The QMAGT system delivers all 9 magnetic tensors, from which the 5 independent tensors are derived for final delivery. The FTMG method brings clear advantages to exploration for kimberlites, but is also valuable in the exploration and characterization of iron ore deposits, ultramafic intrusions, and in complex structural settings – particularly where remanent magnetization is present. The QAMT system measures the Earth’s response to natural EM energy – principally lightning and solar events. The QAMT system measures all three components of the magnetic field, and uses a full-tensor MT base station, necessary for the processing, modeling and final products. The principal advantage of the QAMT system over other natural field airborne EM systems are in its ability to accurately measure all three components of the magnetic field, which significantly improves the resolution of the final imaging and modeling.

Webinar:

A recording of the webinar is available on Youtube.

BCGS Technical Talk – June 18, 2020

Speaker: Dr. Richard Lynch & Dr. Charlie Beard, Sisprobe

Title: Imaging and Monitoring using Ambient Seismic Noise – Dam Wall Monitoring using Fibre Optic (Distributed Acoustic) Sensor, and Mineral Exploration using Nodes

Date/Time: Thursday, June 18, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

While active seismic methods have been used successfully for many decades in mineral and hydrocarbon exploration, passive seismic methods are still in their infancy.  In the past 10 years a popular method in the academic community has been seismic interferometry, in which ambient seismic noise – from traffic, small tremors, ocean waves, etc – is used to create virtual controlled seismic sources.  This method is inexpensive and environmentally friendly since no active seismic equipment is necessary and new ultra-portable seismic nodes can be used to collect the data.  Ambient seismic noise is now being used to construct 3D S-wave velocity images of the subsurface, typically from a few meters down to depths of a few kilometers.  It can also be used to monitor very small velocity changes in the subsurface for applications in dynamic engineered geologic environments, for example CO2 injections, hydrocarbon production and tailings dam wall stability.

This presentation will cover the basic theory of seismic interferometry and how it is used to image and monitor the subsurface.  Two case studies will be shown to illustrate the method: a dam wall in Sweden which is permanently monitored by a Distributed Acoustic Sensing fibre-optic system and a mineral exploration site in Canada where a one month deployment of 1000 seismic nodes was used to image an intrusive body that hosts Cu-Pd mineralisation.

Webinar:

A recording of the webinar is available on Youtube.

BCGS Technical Talk – May 21, 2020

Speaker: Dr. Benjamin Birt, Qteq

Title: Borehole Magnetic Resonance Method and Applications

Date/Time: Thursday, May 21, 2020 @ 4:30pm PST

Location: Online Webinar

Abstract:

One of the more advanced tools in oil and gas industry is the nuclear magnetic resonance tool which has been used since the 70’s to characterise reservoirs for resource estimates. The measurement allows a better understanding/characterisation of a formation with a lithology independent total porosity value. In the last 5+ years this technology has been made available to other resource sectors through decreased size and costs and can play a critical role in determining resources and information required in geotechnical application. Especially in industries where the resource is stored with in the porosity system, whether it be as simple as water or more complex in-situ recovery mines. The log can also be combined with other geophysical logs to get better understanding of dry bulk density and salinity. This presentation introduces the physics of magnetic resonance measurement and the interpretation of the tool’s output. The Borehole Magnetic Resonance measurement can be further analysed using global or core calibrated coefficients to give information about grain size distribution, moveable water (fluid), bound water (fluid), and permeability or hydraulic conductivity as the measurement is sensitive to pore size geometry. The Borehole Magnetic Resonance log can be used by multiple disciplines in the same project – utilized for in situ moisture for mine production, greenfield exploration or a mine extension, while also providing information on tailings settling and geotechnical data on dam wall and downstream ground investigation for potential seepage paths. This presentation will walk through the BMR measurement, how to interpret a basic log and give some examples from several different industries.

Webinar:

A recording of this months webinar is available on Youtube.