Tuesday, July 24, 2018

SearchResearch Challenge (7/25/18): The Mystery of the Salzburg Stream--does it flow uphill?


I've been in Salzburg, Austria
for the past week... 


It's just as lovely as you might imagine--the Alps surround a large river valley, it's endlessly green, and the Altstadt ("old town") is full of medieval streets, lined with churches and shops that have been around for hundreds of years.  And yes, the hills are alive with the sound of music--at least I went to enough concerts to convince me of this.  

The surrounding area has a web of bike/foot paths and streams that seem to run every possible way.  They're lovely, but it's a little confusing when you first arrive, although you learn the paths quickly.  That's when you start to notice the little things--the things that make you say "What?"  

My first big surprise (after I got to know the place a bit) was the peculiar behavior of a stream that I passed often on my walks.  As I walked to the foot of a pathway that climbed up to the castle wall, I had to pass over a small stream.  It was a beautifully flowing stream, just about the platonic ideal of a stream. 

One time while I walked this path I paused for a moment, looking down at the water and noticed that it was flowing from south to north.  That was so unexpected that I dropped a leaf into the water to verify that what I thought I was seeing was actually what was happening.  Why was it so unexpected?  

It looks like the water is flowing uphill!  What?  

The little bridge I was standing on is clearly downhill from the where the stream starts.  It looks for all the world like the stream is running up the hill towards the castle!  

Here's the place (from Google Maps, in 3D mode).  In reality, it's clear that the left part of the picture is uphill from the right part.  


The white building at the top of the image is the old city castle, the Festung Hohensalzburg (that is, the "high Salzburg fortress").  It sits atop the Festungsberg, a hill that rises up over the historic center of town.

Just below the fortress is a patch of forest, and below that is a meadow.  In the middle of the meadow is a stream that ends in a clump of trees and brush.  

Actually, that's what I noticed the first time I walked past--this looks like the source of the stream, the spring from which the stream flows.  As I passed I thought to myself, "Oh, there's a spring, the source of one of the many brooks..."  (Since I grew up in LA, I've always thought of springs as being somehow magical.  I never saw one until I was in my mid-20s, so I notice them.)  

Here's the map of that place.  See the blue line of the stream?  That dotted line is the pathway where I'd walk into the Altstadt.  This all makes sense--it follows exactly parallel to the path, and you can see the little bridge on Brunnhausgasse where I crossed it.  The map suggests that this is the spring source.  



Here's the same scene in the satellite view.   It sure looks like the source of a spring.  


As I walked past, I took a quick photo, just so I'd remember this for SRS. 


Location: https://www.google.com/maps/@47.7945965,13.0444718,18.33z 

But... as you see in this map, the water is flowing from south to north!  How is that possible?  The slope of the hill is increasing from south to north.  



This leads me to this week's SearchResearch Challenge.

How is it that this stream in Salzburg is apparently flowing uphill?  What's the real story behind this gentling flowing brook? How is this possible?  

Once you figure it out, be sure to let us know WHAT you did to come to this understanding.  (I have to admit I was rather surprised when I discovered the answer.) 

Hope you enjoy this Challenge!  


Search on! 


22 comments:

  1. A canal, bottom of which elevates from north to south, hence the water flows uphill.

    Search protocol:
    1. Set a walking path on google map, confirming the north is higher than the south.
    2. Keyword search 'Almkanal' leads to salzburg.info, revealing it's a man-made construction, and flows into River Salzach.
    3. River Salzach being north of the 'Spring', suggesting it's actually the entrance of an underground passage connecting to River Salzach.

    ReplyDelete
    Replies
    1. How did you figure out the term "almkanal"?

      Delete
  2. Based on my research, although I didn't find specific mention of this stream, I would postulate that the stream disappears into an opening in the ground caused by the erosion of surrounding limestone, while also demonstrating a "gravity hill" affect where the topography creates an illusion of water flowing uphill.

    7:43 AM stream OR river THAT FLOWS INTO HOLE IN GROUND - Google Search

    7:43 AM indian river disappears underground - Google Search

    7:44 AM 8 bizarre places on Earth where water disappears | MNN - Mother Nature Network

    7:48 AM Which way direction do (most) rivers flow? | Naked Science Forum

    7:52 AM Hydraulic Jump Calculation

    7:53 AM which direction does water flow - Google Search

    7:53 AM how many rivers flow south to north - Google Search

    7:53 AM Rivers Flowing North

    7:55 AM optical illusion of river flowing uphill - Google Search

    7:55 AM List of gravity hills - Wikipedia

    7:56 AM salzburg gravity hill - Google Search

    7:56 AM Rainberg Hill, Salzburg (Austria)

    "The hill is composed of the "Salzburger Konglomerat" rock, a conglomerate of mainly lime stone rubble that was mined here for millennia."

    7:57 AM stream disappears into limestone - Google Search

    7:58 AM Karst Glossary

    7:58 AM salzburg sinking stream - Google Search

    7:59 AM salzburg "sinking stream" lime stone - Google Search

    7:59 AM salzburg "sinking stream" limestone OR karst - Google Search

    7:59 AM Karst Hydrology Lexicon

    8:07 AM Paleokarst: A Systematic and Regional Review - Google Books

    8:07 AM TENNENGEBIRGE KARST stream disappear* - Google Search

    8:07 AM disappearing streams karst topography - Google Search

    8:08 AM USGS Geology and Geophysics
    "Disappearing streams are streams which terminate abruptly by flowing or seeping into the ground. Disappearing streams are evidence of disrupted surface drainage and thus indicate the presence of an underground drainage system."

    8:00 AM salzburg Glaciokarst - Google Search

    THE GENESIS OF THE TENNENGEBIRGE KARST AND CAVES (SALZBURG, AUSTRIA)

    "The Tennengebirge consists of an overthrust sheet, in which the normal flank has resulted in a gently inclined plateau, slightly higher in the south. The frontal saddle accounts for the sudden northerly slope."

    8:05 AM TENNENGEBIRGE KARST - Google Search

    8:05 AM TENNENGEBIRGE KARST stream disappear - Google Search

    ReplyDelete
  3. Hi Dan
    It looks as though you found part of the old Almkanal of Salzburg based on this map:
    http://ontheworldmap.com/austria/city/salzburg/salzburg-city-center-map.jpg There is a nice description of them here: https://www.atlasobscura.com/places/almkanal-of-salzburg Since it is mainly a tunnel system that rises to the surface only at various places, it may not really be running uphill at this location. Oddly enough you can actually "surf" on it in some spots: https://www.surfertoday.com/surfing/9832-the-worlds-narrowest-wave-ride

    ReplyDelete
    Replies
    1. nice find on the wave potential of the Almkanal! - kinda like Mavericks without the sharks, size, fatalities, etc.… winter must be something… like surfing in Sweden…?
      SURF SERP
      Mavericks
      KQED - bigguns… science

      Delete
  4. How I found it was searching for stream salzburg north south. When this did not turn up any odd phenomenon, I decided to go for a detailed map of the area in case the thing was not a stream. That got me the term Almkanal in the right area of the map and my basic German skills (mountain canal) told me to look closer at that word.

    ReplyDelete
  5. [salzburg stream geology hydrology] finds https://www.sciencedirect.com/science/book/9781856175029 Groundwater hydrology of springs a book from 2010. The abstract from Chapter 10 provides what I had suspected: "About 22 percent of the nation's [Austria's] surface consists of karstic rocks. Most of the large cities like Vienna, Salzburg, Graz, Linz, and Innsbruck are significantly supplied by karst waters."

    It goes on to say that Southeastern Europe is one of the most water rich regions of the world and characterized by numerous large springs. Karst is limestone and similar rocks with large caverns made the water dissolving the rock. Vancouver Island has a huge amount of Karstic rock. The boys in Thailand were stranded in a karstic cavern.

    So, I suggest your spring arises in the south and flows north to disappear down a karst 'rabbit-hole'

    j

    ReplyDelete
    Replies
    1. You went down the same "trail" that I did. What is interesting to me is how this illustrates how important theory is to searching (as Michael P. Lynch talks about in Internet of Us). There is plenty of data on almkanal and on Karst, whether you find one or the other depends on what theory you begin your search with.

      Delete
  6. How is it that this stream in Salzburg is apparently flowing uphill? What's the real story behind this gentling flowing brook? How is this possible?
    Location: https://www.google.com/maps/@47.7945965,13.0444718,18.33z

    First decided to visit the link with the maps you provided. Changed view to satellite and found a name. Searched for that

    [Salzburg Almkanal]

    The Stiftsarmstollen is one of the oldest still operational subterranean aqueducts in Central Europe.

    There [Define Grosses Festspielhaus]

    Opera House which opened in 1960

    The Almkanal and The Big Clean-Up: Why did they go with the name “Almkanal”

    [Almkanal water direction] and [Almkanal water flow direction]

    Atlas Oscura: The medieval network of canals hidden underneath the city is opened to explorers each year.

    [Almkanal water south to north]

    Links to History of the Almkanal in PDF. The file gives the link to

    Almkanal Our Dr. Russell is one of the fews curious about this “Die Fragen nach dem "woher" und "wohin" des Wassers, dem "warum" und "wozu" werden selten gestellt und bleiben meist unbeantwortet. “

    [Salzburg Almkanal where water begins]

    It even powers three hydropower plants:

    [Austria stream flow uphill]

    Explaining uphill rivers scientifically?

    Also learned that Salzburg means: "salt fortress"

    ReplyDelete
    Replies
    1. Tried [Intext:Almkanal unknown facts]

      Schloss Hellbrunn
      Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.
      Almkanal just mentioned in the site as another link to click. Which I did. Sadly was the same already posted from Atlas Oscura

      SALZBURG PHOTOS: ALMKANAL (UNDERGROUND CANAL)

      [intext:almkanal how it works] in All and in books. 3 good links. Sadly 2 have only small fragments

      [Almkanal Salzburg] in videos

      Abtauchen in den Salzburger Almkanal/Dive into the Salzburger Almkanal I don't understand anything but is good way to look inside

      Also searched for #almkanal on different Social Media to view more photos of the place

      Delete
    2. It looks like BBC also reads Dr. Russell's SearchResearch blog and got inspired to also wrote about Avocados, Megafauna and Avocado Toast

      A cultural history of the avocado. A toast to the berry - yes, it's a berry - on National Avocado Day

      Delete
    3. funny find/cross link, Ramón… Dan may get a "big head" if he is acting as a stringer for the BBC, but the writer "seed" has been planted…
      donkey britches
      in Scotland
      stringer
      7 facts
      7/31/18
      on twitter

      Delete
    4. Thanks, Remmij. I like the posts you shared, specially, the one explaining "stringer" not word in Spanish to translate. I think here they are called corresponal. And also the Ponies in sweaters. They look cute

      About avocados:
      Fruits: Berries or Drupes

      Delete
  7. seems it is not a stream, rather part of a water tunnel system - you may want to consider a return trip/exploration in September…
    [looked at GMaps & searched the name…]
    Almkanal
    flowing water
    additional images
    Almkanales site/info

    ReplyDelete
  8. Is it capillary action?? Where small volumes of water to flow uphill, against gravity, so long as the water flows through narrow and small spaces?

    ReplyDelete
  9. There were a few keywords in the description which I used to do a search plus added the word for "stream" in German (from Google Translate) i.e. "Festung Hohensalzburg" brunnhausgasse strom

    The first couple of links mentioned something called the "Almkanal" and when I checked the Google map at https://goo.gl/c61QwC it clearly says the stream is the Almkanal.

    So next step is to Google Almkanal. Lots of references (many in German - but thanks to Google translate all is explained). It's the oldest canal system in Europe which served the area with water. There are several water mills - still operational - which can explain the uphill flow. "The Almkanal now supplies 14 turbines, including the oldest power station in the province of Salzburg.... " (Germany Wikipedia entry)

    ReplyDelete
  10. There were a few keywords in the description which I used to do a search plus added the word for "stream" in German (from Google Translate) i.e. "Festung Hohensalzburg" brunnhausgasse strom

    The first couple of links mentioned something called the "Almkanal" and when I checked the Google map at https://goo.gl/c61QwC it clearly says the stream is the Almkanal.

    So next step is to Google Almkanal. Lots of references (many in German - but thanks to Google translate all is explained). It's the oldest canal system in Europe which served the area with water. There are several water mills - still operational - which can explain the uphill flow. "The Almkanal now supplies 14 turbines, including the oldest power station in the province of Salzburg.... " (Germany Wikipedia entry)

    ReplyDelete