Structural and heat-flow implications of infrared anomalies at Mt. Hood, Oregon

Technical Report · Sat Jan 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/6789284· OSTI ID:6789284

Friedman, J D; Frank, D

Surface thermal features occur in an area of 9700 m/sup 2/ at Mt. Hood, on the basis of an aerial line-scan survey made April 26, 1973. The distribution of the thermal areas below the summit of Mt. Hood, shown on planimetrically corrected maps at 1 : 12,000, suggests structural control by a fracture system and brecciated zone peripheral to a hornblende-dacite plug dome (Crater Rock), and by a concentric fracture system that may have been associated with development of the present crater. The extent and inferred temperature of the thermal areas permits a preliminary estimate of a heat discharge of 10 megawatts, by analogy with similar fumarole and thermal fields of Mt. Baker, Washington. This figure includes a heat loss of 4 megawatts (MW) via conduction, diffusion, evaporation, and radiation to the atmosphere, and a somewhat less certain loss of 6 MW via fumarolic mass transfer of vapor and advective heat loss from runoff and ice melt. The first part of the estimate is based on two-point models for differential radiant exitance and differential flux via conduction, diffusion, evaporation, and radiation from heat balance of the ground surface. Alternate methods for estimating volcanogenic geothermal flux that assume a quasi-steady state heat flow also yield estimates in the 5-11 MW range. Heat loss equivalent to cooling of the dacite plug dome is judged to be insufficient to account for the heat flux at the fumarole fields.

• Research Organization: Geological Survey, Denver, CO (USA); Geological Survey, Seattle, WA (USA)
• OSTI ID: 6789284
• Report Number(s): USGS-OFR-77-599
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150301* -- Geothermal Exploration & Exploration Technology-- Geophysical Techniques & Surveys
AERIAL SURVEYING
COOLING
DISTRIBUTION
ENERGY LOSSES
FAILURES
FRACTURES
FUMAROLES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
Geothermal Legacy
HEAT FLOW
HEAT FLUX
HEAT LOSSES
INFRARED SURVEYS
LOSSES
MASS TRANSFER
NORTH AMERICA
OREGON
PACIFIC NORTHWEST REGION
PHYSICAL PROPERTIES
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
USA
VOLCANOES