A Helicopter-Borne Video Thermal Infrared Survey Of The Rotorua Geothermal Field
Journal Article: A Helicopter-Borne Video Thermal Infrared Survey Of The Rotorua Geothermal Field
AbstractDelineation and monitoring of surface thermal activity at geothermal development sites and in tourist and urban areas is important for safety, planning, scientific and field management reasons. Because the standard ground-based temperature measurement methods employed for such work are incomplete, expensive and often impractical, we have developed a helicopter-borne video thermal infrared scanner technique to replace them. The imagery obtained is conveniently stored on videotape and powerful image processing methods can be applied to it for analysis and interpretation. The first known helicopter-borne video thermal IR scanner survey of an entire geothermal field was conducted over Rotorua in March 1990. This 3 hour survey, which demonstrated the value of the method, covered a total area of 18 km2 at a ground resolution of about 2 m. All previously known thermal areas were clearly defined and several new ones delineated. Examples of features identified included: thermal ground, thermal springs and seepages discharging into streams and lakes, thermal water flowing through open channels and buried culverts, and hot spots in sealed roads and carparks constructed over thermal ground. An example of surface feature change detection is also provided. Large scale lake edge seepages, submerged thermal springs and thermal islets identified by this survey may discharge sufficient geothermal fluid to account for the missing 60% chloride input to Lake Rotorua. This technique has effectively established a baseline for monitoring change in surface thermal activity associated with the Rotorua geothermal field and the method is shown to be useful as a management tool for both exploration and monitoring.
- M. A. Mongillo and C. J. Bromley
- Published Journal
- Geothermics, Date Not Provided
- Not Provided
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M. A. Mongillo,C. J. Bromley. . A Helicopter-Borne Video Thermal Infrared Survey Of The Rotorua Geothermal Field. Geothermics. (!) .