An interesting and little-known fact is that the Danube in Germany does exactly the same for roughly 155 days per year [1], which is called "Donauversinkung" ("swallowing of the Danube"). Between the towns of Immendingen and Fridingen on the Swabian Alb the water just disappears underground [2]. This started to happen around 300 years ago, and until the 1870s nobody knew exactly where it went. They then did experiments with Uranin and ultimately proved that the water re-surfaces in the Aachtopf [3]. Now, the water from the Aachtopf flows directly into Lake Constance, therefore into the Rhine, and therefore into the North Sea. Normally, the Danube flows into the Black Sea, which essentially means that on roughly 155 days per year, the disappearing water moves the European watershed [4], which I find highly fascinating.
E: as the Danube laters flows through the once independent state of Württemberg, and the Rhine through the once independent state of Baden, there was also a nice court battle between them because of the lost water in the 1920s - the "Donauversinkungsfall" [5] ("the court case of the swallowing of the Danube")
Am I understanding correctly that the Danube always seeps into the ground near Immendingen (since 300 years), but if the conditions are dry enough there is not enough water to flow past this sink hole, so all of it drains into the European watershed?
It should be noted that this only the first few hundred meters of the Danube and it's relatively flat there so the exact way the water sheds is probably always subject to changes up there (at least across large spans of time). There are relatively small masses of water that flow up there, so things are not set in stone as much (literally).
For the Doubs, this is well-known that it is losing water under its bed and that the Loue river is this water coming out at a different point.
You can see the source of the Loue[0] on the Wikipedia page. The river is basically coming out of the mountain with already a very high flow rate. This is one of the nicest river in the east part of France, it is a pleasure to walk along or navigate it.
Edit: Found videos[1] where you can see the holes sucking the water in the river bed.
This is one reason why it's prudent to scout rapids before running them. For example, sections of the Brule River in Minnesota are runnable above and below Devil’s Kettle.[0] And by the time you saw the drop, it'd be too late to avoid the falls or sinkhole.
Even so, sinkholes can be subtle enough to miss, and still fatal.[1] Karst is some dangerous geology for boating. Although riverbeds are generally quite smooth, which is pleasant enough if you go for a swim.
There is very likely a sizable cave that exists beneath the river bed, the entrance to which had heretofore been clogged by sediment, which has been washed away by recent rains. Could also be that a choke deep in the cave itself has been washed out, joining it to another cave, which provided enough throughput to drain the river entirely underground.
A Karst[1] geology usually consists of water-soluble rocks and sediment. Over time, water dissolves the rock and creates new passage ways, both above and under-ground.
Sometimes this can be affected by human activities(such as mining, as has happened with aquifer withdrawals and phosphate mining in Central Florida and Clear Springs[2]
Eurasia has lost enough groundwater to affect the movement of the North Pole. That's my theory: groundwater is being consumed by people faster than it's being replenished.
> geologists say the river disappearance is due to large cracks in the karstic riverbed, which empty the river underground like a siphon. It is perhaps the important spring floods that washed away the sediment patches that blocked the holes and fissures.
In Florida, one of the branches of the Suwannee disappears into the Santa Fe River sink at O'Leano [0], supposedly travels 5 more miles underground, then comes back up three miles away at River Rise [1].
In Detroit the buried rivers are called the ghost waters. There has been talk on and off about resurfacing some of them where practical. Can you imagine a gondola ride in the Motor City? Something that I'd sure like to see in my lifetime.
Sensationalism all the way. At least one of the rivers has seen it already in 1 976 (quite recently as far as Geology and Topography go) and several other rivers in several parts of the world do the same or similar things.
Worst case scenario, the water permanently goes elsewhere, either to an aquifer or to another river or lake. People adapt. End of history.
[+] [-] lqet|7 years ago|reply
E: as the Danube laters flows through the once independent state of Württemberg, and the Rhine through the once independent state of Baden, there was also a nice court battle between them because of the lost water in the 1920s - the "Donauversinkungsfall" [5] ("the court case of the swallowing of the Danube")
[1] https://en.wikipedia.org/wiki/Danube_Sinkhole
[2] https://upload.wikimedia.org/wikipedia/commons/2/20/Donauver...
[3] https://en.wikipedia.org/wiki/Aachtopf#/media/File:AachTopfP...
[4] https://en.wikipedia.org/wiki/European_watershed
[5] https://de.wikipedia.org/wiki/Donauversinkungsfall
[+] [-] sophistication|7 years ago|reply
It should be noted that this only the first few hundred meters of the Danube and it's relatively flat there so the exact way the water sheds is probably always subject to changes up there (at least across large spans of time). There are relatively small masses of water that flow up there, so things are not set in stone as much (literally).
[+] [-] dmix|7 years ago|reply
https://en.wikipedia.org/wiki/Stream_capture?oldformat=true
[+] [-] Loic|7 years ago|reply
You can see the source of the Loue[0] on the Wikipedia page. The river is basically coming out of the mountain with already a very high flow rate. This is one of the nicest river in the east part of France, it is a pleasure to walk along or navigate it.
Edit: Found videos[1] where you can see the holes sucking the water in the river bed.
[0]: https://en.wikipedia.org/wiki/Loue
[1]: https://www.estrepublicain.fr/edition-haut-doubs/2018/07/31/...
[+] [-] wott|7 years ago|reply
Suits my definition of drinking water.
[+] [-] mirimir|7 years ago|reply
Even so, sinkholes can be subtle enough to miss, and still fatal.[1] Karst is some dangerous geology for boating. Although riverbeds are generally quite smooth, which is pleasant enough if you go for a swim.
0) http://www.startribune.com/scientists-think-they-ve-solved-t...
1) https://www.boston.com/news/national-news/2018/06/12/sinkhol...
[+] [-] newswriter99|7 years ago|reply
[+] [-] mml|7 years ago|reply
There is very likely a sizable cave that exists beneath the river bed, the entrance to which had heretofore been clogged by sediment, which has been washed away by recent rains. Could also be that a choke deep in the cave itself has been washed out, joining it to another cave, which provided enough throughput to drain the river entirely underground.
[+] [-] sathackr|7 years ago|reply
Sometimes this can be affected by human activities(such as mining, as has happened with aquifer withdrawals and phosphate mining in Central Florida and Clear Springs[2]
[1] https://en.wikipedia.org/wiki/Karst
[2] https://en.wikipedia.org/wiki/Kissingen_Springs
[+] [-] MithrilTuxedo|7 years ago|reply
https://www.jpl.nasa.gov/news/news.php?release=2016-100
[+] [-] davio|7 years ago|reply
https://en.wikipedia.org/wiki/Karst
[+] [-] pcl|7 years ago|reply
> geologists say the river disappearance is due to large cracks in the karstic riverbed, which empty the river underground like a siphon. It is perhaps the important spring floods that washed away the sediment patches that blocked the holes and fissures.
[+] [-] al_ramich|7 years ago|reply
https://www.quora.com/What-is-a-sinkhole-when-it-is-in-water...
[+] [-] jguimont|7 years ago|reply
[+] [-] duxup|7 years ago|reply
Talks about a very visual thing .... doesn't have any photos.
It's crazy because all those media companies fired their photographers and in the age of the internet ... PHOTOS AND VIDEOS ARE IMPORTANT!
[+] [-] chiffre01|7 years ago|reply
[1] https://en.wikipedia.org/wiki/Sinks_Canyon_State_Park
[+] [-] glup|7 years ago|reply
I don't know how common seasonal variation is (per the other comment about the Danube doing a similar thing to the French river).
[+] [-] fuzzfactor|7 years ago|reply
[0] https://www.floridastateparks.org/park/Oleno https://www.youtube.com/watch?v=0JiXOk1pXus
[1] https://www.floridastateparks.org/park/River-Rise
[+] [-] neonate|7 years ago|reply
[+] [-] rmason|7 years ago|reply
http://www.modeldmedia.com/features/ghostwater413.aspx
[+] [-] leandrod|7 years ago|reply
Worst case scenario, the water permanently goes elsewhere, either to an aquifer or to another river or lake. People adapt. End of history.
[+] [-] irrational|7 years ago|reply
So, you are saying this is an Armageddon level event?
[+] [-] MithrilTuxedo|7 years ago|reply
https://www.jpl.nasa.gov/news/news.php?release=2016-100
[+] [-] Zancarius|7 years ago|reply
[+] [-] deedubaya|7 years ago|reply
[+] [-] adictator|7 years ago|reply
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