Before it became the world’s largest geothermal power-producing site, The Geysers was known as the “Gates to Hades,” drawing visitors with its healing waters, steam vents, and wild legends.
Normal Fault
High angle fault that results from extensional stress and forms a steeply dipping planar structure. Slip movement during an earthquake is vertical and down dip. The down-dropped block is called the hanging wall and the uplifted block is called the footwall.
Geothermal Glossary
Word of the Week – Brine
Brine In producing geothermal fields, this term refers to the hot water that is produced from wells. It is rarely as salty as implied. Instead, the salinities of most natural hot waters are commonly less than seawater, but they contain a wide range of rock-forming...
Word of the Week – Cap Rock
Cap Rock A poorly permeable or impermeable layer that overlies a geothermal reservoir. The term is borrowed from the oil industry and was once considered an essential feature of a producing geothermal resource in confining the flow and pressure of hot water....
Word of the Week – Casing Shoe
Casing Shoe In geothermal wells, this is the bottom of the cemented casing string. Below the casing shoe, the well may be unprotected and open to the surrounding rock or lined with a slotted liner. The depth of the casing shoe generally coincides with the top of the...