Areas recently affected by volcanic activity may still be hot enough at depth for the geothermal gradient to be
higher than normal. Hot springs, geysers and fumaroles are fed by water rising from depth which is hotter than
normal.
A geothermal field needs
- a heat source - magma relatively close to the surface
- a supply of water from rain, snow, etc with a small percentage of juvenile water
- access to surface along faults and other fissures
If the underground passages are in the appropriate arrangement, geysers may form as fountains of hot water which
erupt at regular (or not-so-regular) intervals.
The geothermal heat provides a 'free' source of clean, renewable energy which may be
exploited by power stations and for heating homes and offices.
Geopix Study Topic "Geothermal Areas"
- gives full images of the examples shown below, and others, to illustrate the main types of geothermal features
- explains the occurrence of hot springs and geysers
- describes the deposits formed in these areas
- illustrates the main economic uses of geothermal energy
The Geothermal Area Study Topic contains the following pages:
'Geothermal Areas' is part of the Igneous Processes Study Guide CD.
To order this CD go to the Geopix Online Store
