BCGS Fall Workshop: 2017 SEG DISC Short Course

BCGS Fall Workshop: SEG 2017 DISC Short Course

DISC_Logo

Date: Tuesday – Wednesday, December 12-13, 2017
Time 8:00am PST to 9:00pm PST
Registration: Cost:
– Industry US$200
– Students US$50
Registration is through the SEG website. Click the button below to register.
Note: This is a 2-day event. Registration for Dec 12 includes Dec 13.
Location: UBC Robson Square, 800 Robson St, Vancouver, BC V6Z 3B7
Details: DISC 2017 website

SEG DISC 2017 course details

Coffee breaks and lunch will be provided.

Course Content:

Electromagnetics has applications in oil and gas exploration and production, mineral exploration, groundwater exploration and monitoring, geotechnical and environmental industries. Although it has widespread applications as a geophysical technique, it is not generally understood by the geoscience community. As a result it is underutilized, and in some cases, misused, as a technology.

The aim of this course is to provide over two days a fundamental understanding about EM geophysics so that practitioners can decide if an EM technique can help solve their problem, select which type of survey to employ, and set realistic expectations for what information can be gleaned. Case histories, spanning applications from many areas in the geosciences, are used as an underlying framework to bind the material together.  For more information, please see the DISC 2017 online resources at  http://disc2017.geosci.xyz.

We would like to encourage any of our members who have an EM case study at hand, and would like to contribute to the lab material, to contact the DISC 2017 lab team through their website: http://disc2017.geosci.xyz/#contribute.

Day 2: DISC Lab:

Attendees. Bring your EM problem or case study and lets discuss and analyze it as a group.

The DISC Lab days are designed for a smaller group of geoscientists. We ask participants to provide informal 5 min lightning talks about problems of local interest. We will then work as a group to break down the problems in terms of the 7-Step Framework introduced in course. If participants agree, their talks and results from discussions, will be uploaded to the web. By capturing these problems and state-of-progress onto the web, we hope to promote interaction between geoscientists worldwide.

About the Instructor:

Doug is a professor of Geophysics, director of the Geophysical Inversion Facility (GIF) and world leader in geophysical inversions. He is dedicated to making geophysics more useful for solving problems of relevance to society. Doug’s research career has focused upon the development of inversion methodologies and their application to solving applied problems in a variety of fields. Motivated to make geophysics more accessible and engaging, he has and continues to lead efforts for distributing software codes and learning resource material for students and practising geoscientists. In 2017, Doug will be on tour presenting the SEG Distinguished Instructor Short Course with the intention of promoting fundamental understanding about principles of electromagnetics and how the different surveys make use of these principles to tackle a broad spectrum of problems using EM geophysics.

Sponsorship Opportunities:

A big thank you to our sponsors!

Sponsor_Sheet_Export_Nov13crop

Sponsorship opportunities are available!

Your company sponsorship goes towards helping us put on the workshop and to keep registration costs as low as possible, especially for students. The BCGS operates on a not-for-profit basis. Any profit we make from our events goes towards the BCGS scholarship fund, administered by the KEGS Foundation.

Contact a BCGS Executive member to discuss current opportunities.

November 2017 – Technical Talk

BCGS Technical Talk – November 16, 2017

Speaker: Seogi Kang, PhD Candidate, UBC

Title: On recovering distributed induced polarization information from time domain electromagnetic data

Date/Time: Thursday November 16, 2017 @ 4:30pm

Location: 4th Floor Conference Room, Room 451, 409 Granville St. (UK Building at Granville and Hastings), Vancouver

Abstract:

The electrical conductivity of earth materials is frequency-dependent. This is due to a phenomenon known as induced polarization (IP), wherein electrical charges build-up under the application of an electric field. Macroscopically, earth rocks may be considered chargeable, as they act like electric capacitors. The goal of this thesis is to show how IP data can be extracted from geophysical data, then inverted to recover information about chargeable targets. Although both frequency and time-domain electromagnetic (EM) surveys measure IP signals, this presentation will focus solely on time-domain EM (TEM). To recover chargeability information, the following TEM-IP inversion workflow is developed. (1) Extracts a background conductivity model that is free of IP signals. (2) Decouple the TEM and IP signals by subtracting the fundamental responses estimated using the background conductivity. (3) Inverts the resultant IP data to recover pseudo-chargeabilities at multiple times for a set of 3D volumes. This is used to infer the location and dimensions of chargeable targets. (4) Carry out further analyses of pseudo-chargeabilities at multiple times to estimate intrinsic parameters such as a Cole-Cole chargeability and its associated time constant. For grounded sources, the workflow is implemented for a synthetic DC-IP example.

Results show that the early time signals, which are often discarded, can be used to estimate the background conductivity. Applying the workflow to inductive sources such as airborne EM (AEM) is more challenging, as steady-state electric fields are not produced. This was overcome by developing an IP function which (1) accurately characterizes how electric fields from inductive sources buildup in the earth and (2) allows the recovery of a 3D chargeability by solving a linear inverse problem. The efficacy of the aforementioned approach is validated using field AEM surveys over the Mt. Milligan porphyry deposit in British Columbia and Tli Kwi Cho kimberlite deposit in Northwestern Territories. For the kimberlite deposit, the recovered chargeability information is able to distinguish two distinct kimberlite units. To validate the approach, a 3D rock model is constructed using the recovered chargeability and background conductivity. This model is compared against geological models obtained through drilling and shows good agreement.

October 2017 Technical Talk

BCGS Technical Talk – October 12, 2017

Speaker: Joel Jansen, Anglo American plc

Title: Mineral exploration using natural em fields

Date/Time: Thursday October 12, 2017 @ 4:30pm

Location: 4th Floor Conference Room, Room 451, 409 Granville St. (UK Building at Granville and Hastings), Vancouver

Abstract:

Mineral Exploration using Natural EM Fields.

Jansen J. & Cristall J., Anglo American plc

The understanding of the geological processes behind the formation of mineral systems has advanced remarkably over the past two decades and has initiated a re-think with respect to the optimal geophysical methods required to both target and delineate economic ore bodies. The mineral system concept of McCuaig and Hronsky (2014) proposes four critical elements that must combine in various scales over space and time: whole lithosphere architecture, transient favourable geodynamics, fertility, and preservation of the primary depositional zone. They conclude that “[the mineral system concept] focuses mineral exploration strategies on incorporating primary datasets that can map the critical elements of mineral systems at a variety of scales, and particularly the regional to camp scales needed to make exploration decisions.”

With exploration evolving to take a holistic view of the complete mineral system in targeting, geophysics has adapted to making greater use of techniques that can explore scales ranging from deposit to lithospheric. While the geophysical toolbox is filled with many techniques, only a few of them are capable of the depth investigation required to expand our view past the deposit scale: active- and passive-seismics, and methods that make use of the Earth’s natural gravitational, magnetic, and EM fields. Gravity and magnetics are ubiquitous in datasets ranging from continental to prospect scales and the use of seismic techniques in mineral exploration is growing. But nothing compares to natural field EM methods if the goal is 3D conductivity imaging to kilometres depth combined with ease of data collection. Over the past decade, these have become mainstream in mineral exploration, and recent advances in the joint inversion of ground and airborne data are making natural field EM methods an even more powerful tool for resolving complete mineral systems.

Examples of natural field EM techniques applied to a variety of mineral systems over the past decade are presented, beginning with a crustal scale MT transect across the Gawler Craton and the super-giant Olympic Dam IOCG deposit of South Australia, and followed by illustrations from porphyry systems (Collahuasi, Pebble, El Salvador, Los Bronces, Cobre Panama, Resolution, Santa Cecilia, and Morrison) that dominate this paper owing to the economic significance of porphyry copper-gold deposits globally and because of their amenability to large-scale conductivity imaging. Further applications to sedimentary copper (Frontier and Kansanshi), magmatic polymetallic sulphide (Voisey’s Bay), and unconformity-related uranium (McArthur River) deposits are also presented. Together these examples demonstrate the value that natural field EM geophysics can bring to the exploration decision making process when interpreted in context of mineral systems.

Reference:
McCuaig, T.C, and Hronsky, J.M.A, 2014, The mineral system concept: the key to exploration targeting: Economic Geology, Special Publication 18, p. 153-175.

September 2017 University of Victoria Field Trip – CANCELLED

Join the BCGS on September 19 for a day field trip to Vancouver Island!

Participants will attend a behind the scenes tour of the Pacific Geoscience Center followed by a geophysical seminar at the University of Victoria. The day will conclude with a student-industry mixer on campus, providing an opportunity to connect with the next generation of geophysicists.

This is going to be a first class, “behind-the-curtain”, tour of the PGC, put on for BC Geophysicists by the senior research scientists at the facility and will be way beyond what usual visitors receive. Definitely not to be missed.

Event Poster: UVic_FieldTrip_Announcement

The BCGS is proud to support this event by providing a subsidized fee for all attendees. Bus seats are limited, so to avoid disappointment, early bookings are encouraged! If you have further questions please contact the BCGS Executive (info@bcgsonline.org).

Registration Deadline: September 6, 2017

Cost:  Industry $40    Students $20

*Covers roundtrip bus and ferry transportation from Vancouver to Victoria. Food is not included and is the responsibility of each participant.

Payment will be accepted through PayPal. Click on the “Buy Now” button below.

Pacific Geoscience Center Tour

  • The tectonics of western Canada with Dr. John Cassidy – Head of the Earthquake Seismology Section, Geological Survey of Canada
  • Earthquake monitoring and recent events with Dr. Alison Bird – Earthquake Seismologist (GSC and UVic)

University of Victoria Geophysical Seminar

  • “Investigating active crustal faults on Vancouver Island” with Dr. Kristin Morell, Assistant Professor at Uvic
Time Schedule
8:00  Depart from downtown Vancouver
8:30  Bus pickup @ Broadway and Cambie Street, Vancouver
10:00  Ferry from Tsawassen to Schwartz Bay
12:00  Tour of the Pacific Geoscience Center
14:00  Bus to University of Victoria
15:00  University of Victoria Seminar with Kristen Morell, PhD.
16:00  BCGS Panel Discussion – Careers in Geophysics
16:30  Student-Industry mixer on campus
17:45  Bus to Schwartz Bay
19:00  Ferry from Schwartz Bay to Tsawassen
21:00  Bus returns to downtown Vancouver via Cambie and Broadway

 

 

May 2017 Technical Talk

BCGS Technical Talk – May 18, 2017

Speaker: TBA

Title: Presentation of the SimPEG open-source inversion package and associated case studies.

Date/Time: Thursday May 18, 2017 @ 4:30pm

Location: 4th Floor Conference Room, Room 451, 409 Granville St. (UK Building at Granville and Hastings), Vancouver

Abstract:

The SimPEG team will introduce their open-source python geophysical inversion package. DC, potential fields and EM modelling capabilities will be presented along with some case studies. You can already check SimPEG out on their website: http://www.simpeg.xyz