Throughout its history, the University of Toronto has been a world leader in applied geophysics. It has trained hundreds of scientists, many of whom have worked in industry, and has contributed to the development of many other geophysics programs.
The History of Geophysics in Toronto predates the U of T’s founding by a considerable interval. In the first half of the 19th century, growing interest in the earth’s magnetic field, prompted by the observations of the German scientist Carl Friedrich Gauss (1777–1855), led the British authorities to establish a network of magnetic observatories across the British colonies.
In 1840, the first Canadian magnetic observatory was established near the settlement of Fort York. Essentially, this building was the first of what would become the University of Toronto campus. In 1853, this project was transferred to the University of Toronto. Soon after, the original wooden building was replaced by a stone structure that is now located in front of Hart House. The arrival of streetcars, with their powerful electric motors, put an end to magnetic data gathering in Toronto near the end of the 19th century.
The foundation of mining geophysics at the U of T in the late 1920s was driven by a need to bring order to Canadian mining. U of T Professor of Physics Lachlan Gilchrist (1875-1962) was one of three Canadian professors selected by the Geological Survey of Canada to explore magnetic and electrical methods for assessing claims. This effort kicked off decades of research and teaching in electromagnetic (EM) geophysics directed at prospecting in hard rock environments.
Gilchrist’s successor, John Tuzo Wilson (1908–1993), was a celebrated geophysicist who greatly advanced the department’s research in theoretical geophysics. Wilson is famous for his contribution to the understanding of plate tectonics based on the evidence of magnetic striping of the seafloor. He was an adept public figure and administrator, advancing projects such as the Ontario Science Centre.
The geophysics program at the University of Toronto thrived into the 21st century, with graduate students helping to found geophysics programs across Canada and around the world. Several have gone on to found local prospecting companies based on instruments developed during their graduate research.
The UTEM system was developed through graduate research. It is an example of applied EM geophysics.
This receiver is part of an EM prospecting instrument developed by Dr. Yves Lamontagne (1944-2023) during his doctoral research in geophysics in the mid 1970s. One Professor Gordon West’s many graduate students, Lamontagne used this industry-funded technology to establish a thriving local prospecting company.
This instrument measured the magnetic and electric fields induced by a fixed transmitter system over a relatively wide band of frequencies. It was designed to locate deposits of conductive minerals to a greater depth than previous systems.
As a field instrument, this unit is well insulated for use outdoors. An interesting feature of this instrument is the magnetic tape storage, which records field data for later computer analysis.
A Vertical Loop Benchtop Experiment (late 20th c.)
This benchtop teaching experiment was used to teach the process of finding conductive ore deposits.
Over the second half of the 20th century, University of Toronto became a major centre for developing and teaching the electromagnetic (EM) prospecting techniques used to find conductive ores. This was led by Professor Gordon West, who completed his PhD at the Department of Physics under John Tuzo Wilson in 1960.
This Vertical loop experiment represents an early EM prospecting technique. In this basic teaching experiment, students would measure distortions in a magnetic field produced by an electromagnetic coil. Such distortions could be produced by a conductive plate hidden within a table.
Such benchtop teaching instruments represent simplified versions of field equipment. Such experiments are necessary because field instruments are far too sensitive and otherwise impractical to use in an urban campus.
Gravity Meter Model CG-2 (c. 1961 – 1967)
The sensitive instrument for measuring gravity was made in Toronto in the 1960s.
This is a Worden-type gravimeter, an instrument that measures the local pull of gravity using an exquisitely delicate and sensitive handmade quartz mechanism. Such instruments are typically used to locate relatively mineral and petroleum deposits.
This instrument was made in the 1960s by Toronto-based E.J. Sharpe Instruments of Canada Ltd. (later Scintrex Ltd.) It was used by U of T physics graduate student Allan Spector when he took part in a survey of piercement structures found on the Queen Elizabeth Islands of the Canadian Arctic Archipelago. Piercement structures, also known as diapirs, are unusual dome-like geological features.
For decades, research in applied geophysics at the University of Toronto has involved close relationships with a number of companies developing prospecting instruments in Southern Ontario.