Geophysics Collection · Physics · UTSIC
An electrical assembly consisting of a cylindrical plastic platform with two circuit boards mounted along its length. The boards are joined by two connectors. At one end of the assembly is an Ethernet connector. The assembly’s cylindrical form permits it to be mounted and deployed in a cylindrical pressure vessel typical of seafloor instruments.
Accession Number: 2024.ph.891
Alternative Name:
Primary Materials: Plastic (possibly Delrin).
The Ethernet port is marked by a small label featuring a blue stripe and a written number “1”.
Dimensions (cm): Length = 31, Max Diam. = 7.2.
This is the power and communications electronics (receiver controller, or RC) of the receiver system for a time-domain controlled source electromagnetic (CSEM) instrument. It is designed to be housed in a pressure vessel and was used to power up to 5 receiver circuit boards inside other pressure vessels spread at various offsets on the seafloor. It also collected electric field data from those receivers as voltage values.
CSEM is a time-domain technology that uses a dipole transmitter to send an electrical current into the earth’s crust. Induced electric fields created by this current are detected by receivers. By interpreting this data, features within the earth’s crust can be deduced based on resistivity. This system is designed to map resistive hydrates within the seafloor.
This system was designed for deployment to the Canadian North-East Pacific Time-series Undersea Network Experiment (NEPTUNE) underwater marine observatory.
This artifact is in good cosmetic condition. The mounting posts attaching the larger of the two circuit boards to the plastic frames have broken. Two have been reattached with glue. The circuit board is solidly attached.
Associated Instruments:
Physics Electronics Resource Center, University of Toronto Department of Physics.
Date of Manufacture: c. 2009
This artifact is part of a small collection gathered from the office of Dr. Andrei Swidinsky of the University of Toronto Department of Physics in March of 2022.
Reza Mir (2011), Design and Deployment of a Controlled Source EM Instrument on the NEPTUNE Observatory for Long-term Monitoring of Methane Hydrate Deposits. PhD Thesis. Toronto, Ontario : University of Toronto.
Reza Mir and Nigel Edwards (2011), “The assessment and evolution of offshore gas hydrate deposits using seafloor controlled source electromagnetic methodology,” SEG Technical Program Expanded Abstracts : 682-686.
The NEPTUNE CSEM instrument was designed as a component of the NEPTUNE underwater observatory located on the seafloor on the Cascadia Margin offshore Vancouver Island. NEPTUNE, an 800km undersea network, was installed beginning in 2007 to provide power and network connections for undersea instruments.
The CSEM instrument was installed on the NEPTUNE network on September 18-19 of 2009 using the Canadian ROPOS submersible. This artifact may have been used for testing and debugging the version of the receiver controller that was deployed. The instrument was designed by Reza Mir and Nigel Edwards to measure the long-term evolution of undersea gas hydrates, especially the processes of fluid and gas expulsion from the seafloor. NEPTUNE sits on well-studied deposits of gas hydrates.
Gas hydrates are ice-like crystalline compounds of natural gas and water that are formed at low temperature and high pressure. They are an ideal target for the CSEM method due to their resistivity. Gas hydrates are abundant sources of hydrocarbons and may be exploited as a future energy source. They also represent vast concentrations of methane, an important contributor to global warming. Understanding the stability of these hydrate deposits under conditions of global warming is critical for predicting future effects of climate change.
- Donated to UTSIC