geysers, springs, Artesian well

Isostatic rebound :-

This rise of a part of the crust is due to an isostatic adjustment. A large mass, such as an ice sheet/glacier, depresses the crust of the Earth and displaces the mantle below. The depression is about a third the thickness of the ice sheet. After the glacier melts the mantle begins to flow back to its original position pushing the crust back to its original position. This post-glacial rebound, which lags melting of the ice sheet/glacier, is currently occurring in measurable amounts in Scandinavia and the Great Lakes region of North America.

An interesting geomorphological feature created by the same process, but on a smaller scale, is known as dilation-faulting. It occurs within rock where previously compressed rock is allowed to return to its original shape, but more rapidly than can be maintained without faulting, leading to an effect similar to that which would be seen if the rock were hit by a large hammer. This can be observed in recently de-glaciated parts of Iceland.

Geyser :-

A geyser is a hot spring characterized by intermittent discharge of water ejected turbulently and accompanied by a vapour phase (steam).

The formation of geysers is due to particular hydro geological conditions, which exist in only-a-few places on Earth, and so they are a fairly rare phenomenon. Generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Generally, surface water works its way down to an average depth of around 2,134 meters (7,000 ft) where it meets up with hot rocks. The resultant boiling of the pressurized water results in the geyser effect of hot water and steam spraying out of the geyser's surface vent.

About a thousand geysers exist worldwide, roughly half of which are in Yellowstone National Park, United States. A geyser's eruptive activity may change or cease due to ongoing mineral deposition within the geyser plumbing, exchange of functions with nearby hot springs, earthquake influences, and human intervention.

Erupting fountains of liquefied nitrogen have been observed on Neptune's moon Triton, as have; possible signs of carbon dioxide eruptions from Mars' south polar ice cap. These phenomena are also often referred to as geysers. Instead of being driven by geothermal energy, they seem to rely on solar heating aided by a kind of solid-state greenhouse effect. On Triton, the nitrogen may erupt to heights of 8 kilometers (5 mi).

Springs :-

A spring is a point where groundwater flows out of the ground, and is thus where the aquifer surface meets the ground surface.Dependent upon the constancy of the water source (rainfall or snow melt that infiltrates the earth), a spring may be ephemeral (intermittent) or perennial (continuous).

Water issuing from an artesian spring rises to a higher elevation than the top of the confined aquifer from which it issues. When water issues from the ground it may form into a pool or flow downhill, in surface streams. Sometimes a spring is termed a seep.

Minerals become dissolved in the water as it moves through the underground rocks. This may give the water flavor and even carbon dioxide bubbles, depending upon the nature of the geology through which it passes. This is why spring water is often bottled and sold as mineral water, although the term is often the subject of deceptive advertising. Springs that contain significant amounts of minerals are sometimes called 'mineral springs'. Springs that contain large amounts of dissolved sodium salts, mostly sodium carbonate, are called 'soda springs'. Many resorts have developed around mineral springs known as spa towns.

stream carrying the outflow of a spring to a nearby primary stream is called a spring branch or run. The cool water of a spring and its branch may harbor species such as certain trout that are otherwise ill-suited for a warmer local climate.

Water emanating from karst topography is another type of spring, often called a resurgence as much of the water may come from one or more sinkholes at a higher altitude. Karst springs generally are not subjected to as great a degree of ground filtering as spring water which may have continuously passed through soils or a porous aquifer.

Artesian aquifer :-

An artesian aquifer is a confined aquifer containing groundwater that will flow upwards through a well without the need for pumping. Water may-even spurt out of the ground if the natural pressure is high enough. An aquifer provides the water for an artesian well. An aquifer is a layer of soft rock, like limestone or sandstone, that absorbs water from an inlet path. Porous stone is confined between impermeable rocks or clay. This keeps the pressure high, so when the water finds an outlet, it overcomes gravity and goes up instead of down.

In recharging aquifers, this happens because the water table at its recharge zone is at a higher elevation than the head of the well.

"Fossil water" aquifers can also be artesian if they are under sufficient pressure from the surrounding rocks. This is similar to how many newly tapped oil wells are pressurized

Artesian wells were named after the former province of Artois in France, where many artesian wells were drilled by Cartesian monks. The technique was also known much earlier in Syria and Egypt, although whether the monks of Artois learned of it from outside sources or discovered it independently is unknown

The Great Artesian Basin is the largest and deepest artesian basin in the world, occupying 23% of the continent