Springs

This category includes natural sites where water, other liquids, and/or gases reach the surface of the Earth, including locations underwater.

Springs belong to the most "practical" monuments of nature – freshwater springs often serve as important sources of potable water. Thousands of localities with hot springs and mineral springs around the world have developed health care and resort services.

This has led to an unusual situation, wherein the word "springs" is associated with calm and expensive health resorts; whereas the real springs of long ago are instead covered with magnificent buildings.

Powerful natural freshwater springs belong to the most fascinating monuments of nature. Even more exciting is the diversity of unusual springs – mineral springs, hot springs, submarine springs as well as the unusual black smokers. Especially beautiful are such natural rarities as travertine, silica or salt terraces created by warm and hot springs and, especially, geysers.

Springs are a comparatively less studied and explored group of natural phenomena. While it is widely announced that the largest freshwater springs in the world are in Florida; it is less common knowledge that there are even larger ones in the Balkans and Papua New Guinea. We cannot be even sure that we know the largest ones. Even such much sought-after landmarks as geysers are discovered anew – in 2009 a new geyser was discovered in Kamchatka.

Criteria

This diverse category of landmarks does not have a single criterion. Springs need to have very unusual features and/ or to be exceptionally powerful to be included here. All geyser fields and large spring-formed silica/travertine/salt terraces and other unusual formations fit here.

As most springs contain some dissolved substances, mineral springs should also need to have exceptional characteristics to be included here.

Classification

The most common springs are "cold" freshwater springs: in general, the water of these springs tends to have temperatures that are similar to the average yearly temperatures of their respective localities. Such springs mark locations where the aquifer surface meets the ground surface. If a spring is coming from a confined aquifer, it might be forced to flow to the surface. This is an artesian well.

Some of the most powerful springs of the world are river rises – resurgences of rivers after traveling for shorter or longer distances underground. River rises in a way are not true springs and they contain brownish surface water.

Often it happens that the roof of the underground river at some places collapses. These locations are karst windows. Sometimes part of the stream in karst windows is discharged to the surface, while a major part of the stream continues to flow under the ground (see Indian Spring in Florida). This certainly is a true spring – but only the part, which is discharged to the surface, is counted.

Somewhat less common are thermal springs, which have a significantly higher temperature than the mean yearly temperature of their respective localities. In some polar regions, even a 7 °C warm spring is considered a thermal spring.

The water of mineral springs contains dissolved substances and can have an altered taste and various other characteristics. Mineral springs are divided further according to chemical composition e.g. salt springs, chalybeate springs, soda springs etc.

Mineral springs sometimes create unusual formations. Especially impressive are travertine terraces, silica terraces and the very rare salt terraces, but there are also other unusual formations.

Geysers are erupting springs and belong to the most unusual geological attractions. Although geysers are very rare (approximately only 1000 active geysers known), they are found in 20 – 22 countries of the world – more than people generally imagine.

Fumaroles are locations near volcanoes where steam and diverse gases are emitted. Fumaroles emitting sulfurous gases are named also solfataras. In a few cases, these landmarks can be unusual. Such is the case with the fumaroles around Mount Erebus in Antarctica, which have formed towers of frozen ice up to 18 meters in height.

Mudpot – This is a location where weak hot springs or fumaroles reach the surface, containing fine particles. Sometimes these landmarks have unusual colors due to the specific chemical composition of the spring water.

On the ocean floor there are sea vents, or, locations where superheated water from beneath the Earth’s crust is discharged. These springs are of a fascinating variety and are often called black smokers, with some varieties being called white smokers. Other kinds of little-known landmarks are cold seeps, or locations where the ocean bed is slowly seeping hydrocarbon (e.g. methane) rich fluids.

Subcategories

The category of springs has the following subdivisions:

• Geysers
• Thermal springs
• Mineral springs
• Submarine springs
• Spring tufa, travertine and other formations

Wondermondo has the following articles about springs: