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Posts tagged with "hot springs"

Hot Springs in Greenland

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Hat tip to Jón Frímann for reminding me of Greenland’s hot springs.

Hot springs in Greenland have no breaking news value. There are thousands of them, and they have been known ever since the first Scandinavians emigrated to Greenland about a thousand years ago. On the Island of Disko alone there are over 2000 hot springs. The most famous and one of the warmest of them all are however situated on the Uunartoq Island near the village of Alluitsup Paa (in my youth known as Sydprøven in Danish). Over the last 150 years it has been regularly studied by biologists, and over this period measurements at the bottom have constantly shown temperatures ranging from 40°C to 41.9°C, and there is no reason to believe that this temperature range has changed over the last thousand years. Compared with the around 800 hot springs in Iceland with an average water temperature of around 75°C this is not extremely hot - but more like warm, I would say. The difference lies in the volcanic activity in Iceland -- the Greenlandish hot springs are not related to any volcanic activity. Geothermal springs without any connections to volcanoes or hot magmas are however not at all unusual. The water issuing from a hot spring is heated by geothermal heat. In general, the temperature of rocks within the earth increases with depth. If water percolates deeply enough, it will be heated as it comes into contact with hotter rocks, The now warmer water will seek its way upwards through cracks and faults and, if still hot enough, emanate as a hot spring. The water from hot springs in non-volcanic areas is heated in this manner and such springs are known all over the world. Some authors make a distinction between hot springs with water above 37°C and warm springs with water below 37°C (normal human body temperature). There is however no universally accepted definition of a hot spring, so that a hot spring may just mean any spring with water temperatures above its surroundings. Probably the most general definition of a hot spring is that it has the same temperature all year round and is warmer than the location's average temperature.

There are ruins of a nunnery built near the hot springs on the Uunartoq Island after Greenland was Christianized, around 1000, the choice of construction site may have been related to the hot springs. The surface water is usually between 34 and 38 °C and thus well suited for bathing. That the water should contain radium and for that reason have healing properties is a myth however. Radium has never been found in the water, so if it makes you feel well it is rather because of its temperature. Gas bubbles of pure nitrogen are however rising from the bottom. The nitrogen feeds a.o. nitrogen fixating cyanobacteria, that form thick gelatinous microbial mats.

Before the second world war there were plans to utilize the hot water for various purposes, and they even started digging with the intention of building a public swimming bath, but the war made an end to that.



By the way the Greenlandic word uunartoq means something like “is warming”.





Academics

Kamchatka - Geyser Valley

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In Mudslide Buries Geysers I reported about a large landslide that destroyed much of the Geyser Valley in Kamchatka.
For those of you who are not quite sure where Kamchatka is - here is a situation map (centered on the North Pole).

The Valley of the Geysers in Kamchatka is considered one of the great natural wonders of the world. It is the second largest concentration of geysers in the world. The 6 km long basin has approximately ninety geysers and many hot springs. On 3 June 2007 the Valley of Geysers was seriously damaged by a landslide. Here are some photos taken a year later - in July 2008.


The slide dumped millions of m3 of mud and rocks on the valley. One of the landslide's tongues came close to tourist camp buildings in the Geyser Valley. Part of the household buildings were destroyed, while three main houses (hostel, scientist's house and ranger's house) did not suffer. The landslide stopped few meters from the hostel. The photo shows the rim of the landslide a few meters from a house that escaped from being destroyed. Practically the only way of getting to the valley is by helicopter.

The landslide is well covered by text (Russian + English), maps and photos here.


Boardwalk through the valley. The Valley of the Geysers 6,700 km from Moscow, was only discovered in 1941. It was opened to tourists 50 years later, that is only about 17 years ago.


A couple of mud pots. There are many mud pots, both small and large. A mudpot, mud pool or paint pot is a sort of hot spring or fumarole consisting of a pool of usually bubbling mud. Water rises to the surface at a spot where the soil is rich in volcanic ash, clay and other fine particulates. The thickness of the mud usually changes along with seasonal changes in the water table. The mud takes the form of a viscous, often bubbling, slurry. As the boiling mud is often squirted over the brims of the mudpot, a sort of mini-volcano of mud starts to build up. Although mudpots are often called "mud volcanoes", true mud volcanoes are very different in nature. The mud is generally of white to greyish color, but is sometimes stained with reddish or pink spots from iron compounds. When the slurry is particularly colorful, the feature is then called a "paint pot". The slopes of the mud pots in this photo have beautiful mud cracks. Mud cracks form when muddy sediment dries up. They have a characteristic polygonal shape. They are also called desiccation cracks (desiccation is the state of extreme dryness, or the process of extreme drying).

http://www.ewpnet.co.uk/kamchatka/geyser.htm
http://www.kamchatka.org.ru/geysers.html
http://spanishflyer.livejournal.com/7519.html
http://news.bbc.co.uk/2/hi/europe/6723567.stm



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