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Energy from Water

GEOTHERMAL ENERGY RESOURCES

MSH hot stream. 37 Kb

Hot stream flowing from the crater area, Mount St Helens. Photo by Roger Suthren


     
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Geothermal Energy slide show
(Geothermal Education Office)

 

Definitions

geothermal gradient is the vertical change of temperature with depth, measured in degrees Kelvin per kilometre, °K km-1

units of geothermal heat flow are Joules per square metre per second, Jm-2s-1. However, one Joule per second = 1 Watt (W), so that heat flow is usually expressed as Wm-2, or more conveniently, mWm-2 (milliwatts per square metre).

Heat flow is determined by measuring geothermal gradient in a borehole and thermal conductivity of the rock drilled.

Heat sources for geothermal energy are:

Classification of areas of the earth's surface, according to geothermal potential:
  1. non-thermal areas, geothermal gradient 10 to 40 °K km-1
  2. thermal areas semithermal areas, geotherm up to 70 - 80 °K km-1
  3. hyperthermal areas, geotherm many times greater than in non-thermal areas
Promising areas for geothermal exploration are associated with one or more of these indicators: Requirements for a hydrothermal field

Links to information sources on the Web

Below are just a few of the thousands of links to geothermal energy information on the Web.

General

Geothermal Exploration

Online books

Geothermal resources by region

Iceland

 

USA

Applications of Geothermal Energy

Consequences of Geothermal Exploitation



 

Selected references on geothermal energy

Books:

Periodicals:

Videos:


Case Studies

YELLOWSTONE GEOTHERMAL AREA, WYOMING/MONTANA/IDAHO, U.S.A.

Porkchop Geyser. 19 Kb Porkchop Geyser, Yellowstone, in 1989. Since this time, a large steam explosion has destroyed the geyser. Photo by Roger Suthren

Geology:

Geophysics:

A variety of geophysical anomalies coincide with the 0.6 Ma caldera:

All this indicates that the magmatic system is still active, and that magma underlies much of the caldera at 5-10 km depth (as little as 3 km in the east?).

The hydrothermal system:

References: FOURNIER, R.O. 1989. Geochemistry and dynamics of the Yellowstone National Park hydrothermal system. Annual Review of Earth and Planetary Sciences, 17, 13-53.

VALLES GEOTHERMAL AREA, NEW MEXICO, USA

Valles caldera. 22 Kb View of part of the Valles Caldera, New Mexico, showing the large resurgent dome where much hydrothermal activity is located. Photo by Roger Suthren

Geology:

Hydrology: The geothermal/hydrothermal system: The hot dry rock system: References:

This page is maintained by Roger Suthren. Last updated 1 March, 2017 11:04 PM