Tropical Karst on the Mekong - for Foozi
|Copyright: James Parker (Jamesp)
|Date Taken: 2004-09|
|Categories: Rain Forest, Mountain, River|
|Exposure: f/5.6, 1/250 seconds|
|More Photo Info: [view]|
|Photo Version: Original Version|
|Date Submitted: 2010-01-24 8:22|
|[Note Guidelines] Photographer's Note|
|Foozi has been posting a series of tropical Karst landforms from Malaysia. This is a more massive example from Laos by the Mekong River - the forset covered mountains in the BG(I included the river boat at the time as a sense of scale). Karst or limestone topography is an important feature in many areas of the world - in the UK, the Peak District and Yorkshire Dales National Parks, in France the Gorges of the Tarn, much of Croatia ..... and in the tropics the features are far more extreme because of higher rainfall and temperatures - one of the most famous examples in Gilin in China.|
This was one of my first outings with a digital SLR and still exhibits many of the features of my film photography - film was expensive, bulky and difficult to store, so I included as many features as possible in the frame!
Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite.
Due to subterranean drainage, there may be very limited surface water, even to the absence of all rivers and lakes. Many karst regions display distinctive surface features, with sinkholes or dolines being the most common. However, distinctive karst surface features may be completely absent where the soluble rock is mantled (covered - in more northerly areas), such as by glacial debris, or confined by a superimposed non-soluble rock strata.
Karst topography is charactarized by subterranean limestone caverns, carved by groundwater.The geographer Jovan Cvijić (1865–1927) was born in western Serbia and studied widely in the Dinaric Kras region. His publication of Das Karstphänomen (1893) established that rock dissolution was the key process and that it created most types of dolines, "the diagnostic karst landforms". The Dinaric Kras thus became the type area for dissolutional landforms and aquifers; the regional name kras, Germanicised as "karst", is now applied to modern and paleo-dissolutional phenomena worldwide. Cvijić related the complex behaviour of karstic aquifers to development of solutional conduit networks and linked it to a cycle of landform evolution. He is recognized as "the father of karst geomorphology".
Different terms for karst topography exist in other languages—for example, yanrong in Chinese and tsingy in Malagasy. The international community has settled on karst, the German name for Kras, a region in Slovenia partially extending into Italy, where it is called "Carso" and where the first scientific research of a karst topography was made. The name has an Indo-European origin (from karra meaning "stone"), and in antiquity it was called "Carusardius" in Latin. The Slovene form grast is attested since 1177, and the Croatian kras since 1230.
Karst landforms are generally the result of mildly acidic water acting on soluble bedrock such as limestone or dolostone. The carbonic acid that causes these features is formed as rain passes through the atmosphere picking up CO2, which dissolves in the water. Once the rain reaches the ground, it may pass through soil that may provide further CO2 to form a weak carbonic acid solution: H2O + CO2 → H2CO3 (the acid). Recent studies of sulfates, in karst waters, suggests sulfuric acid and hydrosulfuric acid may also play an important role in karst formation (so volcanic activity and acid rain can also have an effect).
This mildly acidic water begins to dissolve the surface along with any fractures or bedding planes in the limestone bedrock. Over time, these fractures enlarge as the bedrock continues to dissolve. Openings in the rock increase in size, and an underground drainage system begins to develop, allowing more water to pass through the area, and accelerating the formation of underground karst features.
Somewhat less common than this limestone karst is gypsum karst, where the solubility of the mineral gypsum provides many similar structures to the dissolution and redeposition of calcium carbonate.
The karstification of a landscape may result in a variety of large or small scale features both on the surface and beneath. On exposed surfaces, small features may include flutes, runnels, clints and grikes, collectively called karren or lapiez. Medium-sized surface features may include sinkholes or cenotes (closed basins), vertical shafts, foibe (inverted funnel shaped sinkholes), disappearing streams, and reappearing springs. Large-scale features may include limestone pavements, poljes and blind valleys. Mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers or haystack/eggbox landscapes. Beneath the surface, complex underground drainage systems (such as karst aquifers) and extensive caves and cavern systems may form.
Erosion along limestone shores, notably in the tropics, produces karst topography that includes a sharp makatea surface above the normal reach of the sea and undercuts that are mostly the result of biological activity or bioerosion at or a little above mean sea level. Some of the most dramatic of these formations can be seen in Thailand's Phangnga Bay and Halong Bay in Vietnam.
Calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide. Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time. In caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals.
This was taken with a Canon 10D
marianas, Dis. Ac., siggi, Adanac, zulfu, anemone, boreocypriensis, foozi, corjan3 has marked this note useful
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- [2010-01-24 8:55]
beautiful landscape. What I wanted to be there on the boat and I therefore ... !!
Exceptional employment and playback of photo, congratulations.
Have a beautiful evening,
What a great place!
And what a lovely both!
Great landscape, wonderful ans mysterious light!
i am more a fan of nature photos wher there is no sign of
civilisation but i understand your point of view by including the boat,
a lovely landscape photo with the mountains covered by the Rain Forest,
fine POV, DOF and wide angle framing, i love the clouds of the photo,
- [2010-01-24 10:54]
Nice perspective picture. When it is not raining you can expect bright sun in this tropical zone. Lovely scene of this winding water way. Very well done and tfs.
Best regards Siggi
- [2010-01-24 19:09]
It is great to look back at times, this is a wonderful landscape from your archives. What a magical looking place, thank you for sharing.
- [2010-01-24 23:01]
Very lovely and excellent scene shot. Colours, details and composition are very beautiul. Nice dedication too.
TFS ang G's,
Hello James. Beautiful scenery. I love the foggy mountains and colour of the water here. Fine composition too.
TFS. Kind regards,
Hi again Bro James,
Great landscape capture of these tropical Karst landforms with great notes as usual. Delightful composition and pleasant dedication to our friend Foozi too.
TFS and have a nice day!
- [2010-01-25 4:41]
first of all...this is a real surprise for me to have a wonderful karst shot from an experience and knowledgeable person. Im touched by the dedication. How appreciate it I cant really measure it. I feel so excited too.
you have presentedit so lovely with the Mekong river as it foreground and the tropical karst and forest.
Besides the photo, it is the notes that really educate me on natural phenomena.
Thanks a lot Mr. Parker, I really appreciate your excellent
photos from various countries.
I am very familiar with Karstic regions as I have worked on several and I am very impressed with your thorough research on the occurrence and development of Karst. I commend you for the excellent note and the photo, taken on the Mekong, one of the major rivers of the world, complements it very well. Thank you.