Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: Gastrula to Glow discharge

Geyser

water pressure steam channels

A geyser is an intermittent or semi-regularly periodic spout of geothermally heated groundwater and steam.

Any subsurface encounter between water and heat produces a hydrothermal process. The heat is usually supplied by upwellings of magma from the mantle, the water by precipitation that percolates downward through surface rocks. Some oceanic water enters the mantle at subduction zones and becomes an important ingredient in upper-mantle magmas.

Most hydrothermal processes are driven by convection. Convection occurs because water, like most substances, expands when heated. The result is that hot water rises and cool water sinks. Convection occurs when any water-permeated part of the earth's crust is heated from below: heated water fountains upward over the hot spot and cool water descends around its edges. These movements occur through cracks and channels in the rock, forcing the water to move slowly and remain in constant contact with various minerals. Water convecting through rock is thus an effective means of dissolving, transporting, and depositing minerals. Most deposits of concentrated minerals, including large, shapely crystals, are created by hydrothermal processes.

Manifestations of hydrothermal processes can be dramatic, including the geysers and hot springs that sometimes occur where shallow magma is present. However, The geyser, Old Faithful, located in Yellowstone National Park (Wyoming). Photograph by John Noble. CORBIS/John Noble. Reproduced by permission.
most hydrothermal circulation occurs inconspicuously in the vicinity of large magmatic intrusions. These can cause water to convect through the rocks for miles around.

Some geysers erupt as perdictable intervals, others irregularly; a few send jets of water and steam hundreds of feet into the air, others only a few feet. There are fewer than 700 geysers in the world, all concentrated in a few dozen fields. More than 60% of the world's geysers are in Yellowstone National Park in the northwestern United States, including the famous geyser, "Old Faithful."

The word geyser comes from the name of a single Icelandic geyser, Geysir, written mention of which dates back to A.D. 1294.

Geysers form only under special conditions. First, a system of underground channels must exist in the form of a vertical neck or series of chambers. The exact arrangement cannot be observed directly, and probably varies from geyser to geyser. This system of channels must vent at the surface. Second, water deep in the system—tens or hundreds of meters underground—must be in contact with or close proximity to magma. Third, this water must come in contact with some rock rich in silica (silicon dioxide, SiO2), usually rhyolite.

Silica dissolves in the hot water and is chemically altered in solution. As this water moves toward the surface, it deposits some of this chemically altered silica on the inner surfaces of the channels through which it flows, coating and sealing them with a form of opal termed sinter. Sinter sealing allows water and steam to be forced through the channels at high pressure; otherwise, the pressure would be dissipated through various cracks and side-channels.

The episodic nature of geyser flow also depends on the fact that the boiling point of water is a function of pressure. In a vacuum (zero pressure), liquid water boils at 0°C; under high pressure, water can remain liquid at many hundreds of degrees. Water heated above 100°C but kept liquid by high pressure is said to be superheated.

The sequence of events in an erupting geyser follows a repeating sequence. First, groundwater seeps into the geyser's reservoirs (largely emptied by the previous eruption), where it is heated—eventually, superheated—by nearby magma. Steam bubbles then form in the upper part of the system, where the boiling point is lower because the pressure is lower. The steam bubbles eject some water onto the surface and this takes weight off water deeper in the system, rapidly lowering its pressure and therefore its boiling point. Ultimately, the deeper water flashes to steam, forcing a mixed jet of water and steam through the geyser's surface vent.

Many of the world's geysers are endangered by drilling for geothermal energy in their vicinity. Drilling draws off water and heat, disrupting the unusual balance of underground conditions that makes a geyser possible.

See also Bedrock.

User Comments

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or

Vote down Vote up

11 months ago

Packers and Movers Hyderabad @
http://packersandmovershyderabad.top3rd.co.in
Packers and Movers Bangalore @
http://packersandmoversbangalore.top3rd.co.in
Packers and Movers Pune @
http://packersandmoverspune.top3rd.co.in
Packers and Movers Mumbai @
http://packersandmoversmumbai.top3rd.co.in
Packers and Movers Chennai @
http://packersandmoverschennai.top3rd.co.in
Packers and Movers Delhi @
http://packersandmoversdelhi.top3rd.co.in

Vote down Vote up

11 months ago

Packers and Movers Hyderabad @
http://ipackersmovershyderabad.top4th.in
Packers and Movers Bangalore @
http://ipackersmoversbangalore.top4th.in
Packers and Movers Pune @
http://ipackersmoverspune.top4th.in
Packers and Movers Mumbai @
http://ipackersmoversmumbai.top4th.in
Packers and Movers Chennai @
http://ipackersmoverschennai.top4th.in
Packers and Movers Delhi @
http://ipackersmoversdelhi.top4th.in
Packers and Movers Gurgaon @
http://ipackersmoversgurgaon.top4th.in

Vote down Vote up

11 months ago


Packers and Movers Hyderabad @
http://packersmovershyderabad.top3rd.in
Packers and Movers Bangalore @
http://packersmoversbangalore.top3rd.in
Packers and Movers Pune @
http://packersmoverspune.top3rd.in
Packers and Movers Mumbai @
http://packersmoversmumbai.top3rd.in
Packers and Movers Chennai @
http://packersmoverschennai.top3rd.in
Packers and Movers Delhi @
http://packersmoversdelhi.top3rd.in
Packers and Movers Gurgaon @
http://packersmoversgurgaon.top3rd.in

Vote down Vote up

11 months ago


Packers and Movers Hyderabad @
http://packersmovershyderabad.top3rd.in
Packers and Movers Bangalore @
http://packersmoversbangalore.top3rd.in
Packers and Movers Pune @
http://packersmoverspune.top3rd.in
Packers and Movers Mumbai @
http://packersmoversmumbai.top3rd.in
Packers and Movers Chennai @
http://packersmoverschennai.top3rd.in
Packers and Movers Delhi @
http://packersmoversdelhi.top3rd.in
Packers and Movers Gurgaon @
http://packersmoversgurgaon.top3rd.in

Vote down Vote up

over 1 year ago

Thanks for more information about visit this link:
http://www.adword.co.in/packers-and-movers-hyderabad/
http://www.adword.co.in/packers-and-movers-mumbai/
http://www.adword.co.in/packers-and-movers-pune/

Vote down Vote up

over 1 year ago

Thanks for more information about visit this link:
http://www.adword.co.in/packers-and-movers-bangalore/
http://www.adword.co.in/packers-and-movers-delhi/
http://www.adword.co.in/packers-and-movers-gurgaon/
http://www.adword.co.in/

Vote down Vote up

over 1 year ago

Thanks for More information provide Top 3th Packers and Movers services
http://3th.co.in/packers-and-movers-delhi/
http://3th.co.in/packers-and-movers-noida/
http://3th.co.in/packers-and-movers-faridabad/
http://3th.co.in/packers-and-movers-ghaziabad/

Vote down Vote up

over 1 year ago

Thanks for More information provide Export5th in packing & moving services at best shifting
http://www.export5th.in/packers-and-movers-in-bangalore/
http://www.export5th.in/packers-and-movers-in-hyderabad/
http://www.export5th.in/packers-and-movers-in-pune/
http://www.export5th.in/packers-and-movers-in-mumbai/

Vote down Vote up

almost 2 years ago

Crystal X Mengatasi Keputihan
http://www.crystalxmengatasikeputihan.com
Keunggulan Produk Herbal Crystal X
http://www.crystalxmengatasikeputihan.com/2015/04/keunggulan-dari-crystal-x.html
Crystal X
http://distributor-resmi-nasa.blogspot.com/2013/05/manfaat-dan-bahaya-crystal-x.html
CRYSTAL X UNTUK PROGRAM HAMIL
http://www.crystalxmengatasikeputihan.com/2015/04/crystal-x-untuk-program-hamil-istri.html
Produk Terapi Untuk Suami Agar Istri Cepat Hamil
http://www.crystalxmengatasikeputihan.com/2015/04/produk-terapi-untuk-suami-agar-istri-cepat-hamil.html
Cara Pemesanan Produk Crytal X
http://www.crystalxmengatasikeputihan.com/p/blog-page.html
Cara Pemakaian Crystal X untuk Hasil Memuaskan
http://www.crystalxmengatasikeputihan.com/2015/04/cara-pemakaian-crystal-x-untuk-hasil.html
Crystal X Benar-Benar Aman
http://www.crystalxmengatasikeputihan.com/2015/04/apakah-crystal-x-benar-benar-aman_22.html
Khasiat Crystal X Merawat Organ Intim
http://www.crystalxmengatasikeputihan.com/2015/04/khasiat-crystal-x-merawat-organ-intim.html
Mengatasi Keputihan Dengan Crystal X
http://www.crystalxmengatasikeputihan.com/2015/04/mengatasi-keputihan-dengan-crystal-x.html
Peranan Crystal X Sebagai Pembunuh Bakteri Jahat
http://www.crystalxmengatasikeputihan.com/2015/04/peranan-crystal-x-sebagai-pembunuh.html
Fungsi Crystal X Untuk Memperlancar Menstruasi
http://www.crystalxmengatasikeputihan.com/2015/04/fungsi-crystal-x-untuk-memperlancar.html
Efek Samping Penggunaan Crystal X
http://www.crystalxmengatasikeputihan.com/2015/04/efek-samping-penggunaan-crystal-x.html
Mengatasi Keputihan Dengan Crystal X
http://www.crystalxmengatasikeputihan.com/2015/04/mengatasi-keputihan-dengan-crystal-x.html
Cara Mengatasi Keputihan Tanpa Efek Samping
http://www.crystalxmengatasikeputihan.com/2015/05/cara-mengatasi-keputihan-tanpa-efek.html