(SI) Čudovit dvopramenski slap v svojih najlepših letih!
PRED ZACETKOM:
Opis tega Geološkega zaklada je dolg. Prosimo, preberite ga in si zapisite naloge za vpis se pred obiskom zaklada!
NALOGE ZA VPIS OBISKA
1. Ozrite se nad izvir slapa. S pogledom lahko jasno sledite smeri prelomnice, vse od izvira slapa do vrha stene. Kako so usmerjene plasti kamnin levo, oziroma jugozahodno od prelomnice?
2. Visji slap najprej drsi po skali pod kotom 50 stopinj. Koliksna je dolzina tega dela slapa preden se prelomi v skoraj navpicen padec proti tolmunu? Odgovor najdete na informacijski tabli ob poti k slapu.
3. Kolikšna je nadmorska višina kraškega izvira od katerega pada višji slap? Odgovor najdete tudi na informacijski tabli.
4. Zelo bomo veseli, ce kaksno zanimivo fotografijo z mesta zaklada prilozite svojemu vpisu (logu) obiska.
POMEMBNO!
- Preden vpisete obisk zaklada, posljite odgovore preko GC profila ali neposredno na e-naslov vane.si.geo@gmail.com. Takoj potem lahko vpisete obisk zaklada na spletu – ne potrebujete dodatnega dovoljenja. Ce ste fotografirali, prosimo, prilozite kaksno fotografijo.
- Vpisi brez ustrezne spremljajoce e-poste, ki vsebuje pravilne odgovore, bodo najprej trajno kodirani, kasneje izbrisani!
- Vpisi, ki vsebujejo odgovor bodo izbrisani!
(ENG) Beautiful double waterfall in its prime!
BEFORE THE BEGINNING:
This EarthCache has a long description! Please, read it and write down logging tasks before visiting the EarthCache site!
LOGGING TASKS
1. Take a look above the waterfall spring. You can clearly see the direction of the fault, all the way from waterfall up to the top of the cliff. The rock layers on the left, South-Western side of the fault are inclined. How?
2. First part of higher waterfall slides down at an angle of 50 deg. What is the length of the slide before water plunges almost vertically? Consult information board on the trail to waterfall.
3. What is the altitude of the karst spring which delivers water to the higher part of waterfall? You can find answer on the info board too.
4. We would be glad if you added interesting photos from the EarthCache location to your log.
IMPORTANT!
- Send answers through GC profile or directly to e-mail vane.si.geo@gmail.com
before logging. After that you can log - you don't need an additional permission to log. Please, upload photos if you have taken them.
- Logs without an accompanying e-mail containing correct answers will be encrypted and later deleted!
- Logs containing the answer will be deleted!
slovensko besedilo / Slovenian text
tocke poti in dnevniki / waypoints and logs
Visit our web-site Geološki zakladi / EarthCaches
for a complete list of our EarthCaches and a lot of additional information.
(ENG) FAMOUS WATERFALL
Savica is one of the most beautiful Slovenian waterfalls, and definitely the most famous one! It is one of the stars among the natural wonders in many tourist guides and brochures. One can not deny its beauty, but in the minds and hearts of Slovenian people it is painted as THE waterfall, because it has a special place in the literature! The fame of Savica started to spread in the 17th century, when Janez Vajkard Valvasor, member of the Royal Society, described it as one of the natural wonders in his extensive work The Glory of the Duchy of Carniola. While already our first poet, Valentin Vodnik, has been inspired by the waterfall, the most cherished and renowned Slovenian poet France Preseren, has been completely enchanted by it! Enough to devote his masterpiece, The Baptism at The Savica, to the waterfall. Every Slovenian child is taught about Savica and those poems in primary school, many children visit waterfall during their natural science field-excursions, the rest together with parents. So, almost every Slovenian has visited Savica at least once.
Figure 1: A - an old photo, cca 1900, Karel Hinterlechner, reference 4; B - normal water level, Stane Klemenc, from book Slapovi, reference 5; C - high water level and a nice rainbow, gregax, reference 6;
BITS OF SPLENDID HISTORY
Triglav lakes valley lies between 1350 and 2000m a.s.l., Bohinj lake basin (at lake surface) is at 525m i.e. today. Geologists think both valleys have been one long, continuous valley in Lower Pliocen, about 6 million years ago, and Sava Bohinjka river has been flowing on the surface along length of the valley. At that time, the collision of Adria micro-tectonic plate and Eurasian tectonic plate produced South-Alpine thrusting episode – in other words, it caused uplift of Julian Alps. Bohinj lake basin has not followed this uplift – it has been left behind due to its tectonic disposition. During ice ages Bohinj lake basin has been widened and carved even deeper. Water, with its erosion and dissolution ability had no trouble to find new ways from higher valley to the basin floor – underground, widening fissures and carving caves through limestone.
INTERESTING SITUATION TODAY
Savica is a double waterfall and, one could say, in its best age now! At normal water level higher waterfall springs at about 836m a.s.l. and lower at 790m. At first glance you could think, lower waterfall is somehow just branching from the large one in the middle of the cliff. Yet, it is not so! Especially since at low water levels only lower waterfall springs! How is that and why? Researchers have found an answer to that question in 1949, when they managed to penetrate about 100m into the cave behind (higher) waterfall source.
Waters of Savica have carved their way through stone along the fault line, which cuts cliffs in direction SE - NW, with fault plane slanted about 45 degrees towards South. The cave, or the water channel behind the waterfall spring, is almost horizontal.
Cross-sections of the channel (see Image 2) clearly show that it follows the fault. There is a lake 40m long and 4m deep not far from the cave entrance. Behind it is the second lake, just 5m long and some meters further, two more small lakes.
Figure 2: Numbers (1 to 4) indicate subsequent lakes in the direction of the water flow; Letters (a to f) indicate cross sections; Black arrow shows direction of the incoming water; Blue arrows show direction of the water that drains through fissure to the lower waterfall; Dashed red lines indicate fault plane direction.
Sketch from book Slapovi Slovenije, Anotn Ramovs, see reference No.1; Part of the water channel researched until 1949 is shown; Cross section lines and fault plane lines added by vane_si.
Researchers have discovered that not all of the water flows into the large lake (number 4 at the image 2), because there is an open fissure at the bottom of the small lake (No. 3)! This fissure is the fault line itself, widened by water! So, rather large quantity of water escapes main water channel, flows down the fault plane, and springs as the small waterfall! Still, the fissure is too narrow to drain all the water at normal water level. Therefore usually major part of water still reaches larger lake and source of the higher waterfall from there.
Compare photos B and C at Image 1 – it is clear, that amount of water in the lower waterfall doesn’t change even when the water level rises dramatically from normal to very high! This fact is additional confirmation that lower waterfall is only fed by water draining through fissures in the main water channel – which can only drain limited amount of water – everything else must come to light in the source of higher waterfall!
In decades that followed, cave divers reached even deeper into the mountain (see Image 3). First they had to swim through 300m long siphon and continued somewhat further. They have reached about 560m deep into the mountain so far.
Figure 3: Section of the Savica waterfall and the water channel explored until now.
FUTURE SPELLS THE END OF GLORY
At the time of drought when water level is low, or in the winter when headwaters freeze, visitors can glimpse into the future! In time, water will widen fissure inside the water channel enough to drain all the water. Geologically speaking, this time is just around the corner! Then lower waterfall is all there will be left of Savica. For short time, at least… since everything is constantly changing in the endless battle between forces of erosion and forces of mountain building.
EARTHCACHE AND ACCESS TO WATERFALL
In the warmer period of the year, usually from April to October, there are a parking fee and an entrance fee to pay. A short walk uphill takes you from parking lot to the trail entrance. EarthCache coordinates are set at that point.
Partially paved trail with many stairs will take you from entrance all the way to the waterfall in about 15 minutes. There are more than 500 stairs on the trail - if you were with children, they could try to count them… A wooden pavilion is set at the view point in front of the waterfall. Usually you can descend closer to the waterfall pool, while in the time of high waters, thick spray of water droplets could get you soaking wet already at the view point!
Note: You use trails at your own risk. Use only trails you are fit to. Be safe and enjoy!
REFERENCES
1. Anton Ramovs, Slapovi v Sloveniji, Slovenska matica, Ljubljana, 1983;
2. Rok Kuslan, Slapovi, Sidarta, Ljubljana, 2008;
3. Ivan Gams, Kras v Sloveniji (Karst in Slovenia), ZRC Publishing, The Scientific research centre of the Slovenian Academy of Sciences and Arts, Ljubljana, 2004;
4. Photo A: Karel Hinterlechner, Slovenian geologist, petrologist, mineralogist, philosopher, teacher; photo taken cca 1900;
5. Photo B: Stane klemenc, from book Slapovi, see reference No. 2.
6. Photo C: gregax, from website “pictureslovenia.com;
Slovensko besedilo
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za seznam vseh nasih Geoloških zakladov in mnogo dodatnih podatkov.
(SI) SLAVNI SLAP
Slap Savica je zagotovo eden najlepsih pri nas, nedvomno pa je najslavnejsi in najbolj poznan! Na turisticnih prospektih in v vodnikih mu pogosto dodelijo zvezdnisko vlogo med naravnimi znamenitostmi. Ne moremo zanikati njegove lepote, a v srcih slovencev je zapisan s posebnimi crkami, kot TISTI slap. Na kateri slap pomislite najprej, ce slisite besedo »slap«? Vsekakor je Savica drugacna zato, ker ima posebno mesto v nasi literaturi in kulturi. Slavo Savice je prvi, ze v 17. stoletju ponesel v svet Janez Vajkard Valvasor v svoji obsezni Slavi vojvodine Kranjske. Nasega prvega pesnika, Valentina Vodnika je Savica ocarala, Franceta Preserna pa ze kar urocila! Tako mocno, da ji je posvetil svojo epsko pesnitev Krst pri Savici.
Vsi otroci pri nas se o Savici in njej namenjenih pesnitvah ucijo ze v osnovni soli. Mnogi ga obiscejo s solsko ekskurzijo, v okviru naravoslovnih dejavnosti, ostali pa s starsi. Tako skorajda vsak Slovenec vsaj enkrat obisce Savico.
Slika 1: A – stara fotografija nastala okoli leta 1900, Karel Hinterlechner, vir 4; B – obicajen vodni pretok, Stane Klemenc, iz knjige Slapovi, vir 5; C – visok vodostaj in cudovita mavrica, gregax, vir 6;
KOSCKI MOGOCNE ZGODOVINE
Dolina Triglavskih jezer lezi na nadmorski visini od 1350 do 2000m, udorina Bohinjskega jezera (na gladini) pa je danes na 525 metrih. Po podatkih geologov, sta obe dolini v spodnjem Pliocenu, pred priblizno 6 milijoni let, sestavljali eno samo, neprekinjeno dolino, po kateri je na povrsju tekla Sava Bohinjka. Tedaj se je zaradi podrivanja Jadranske mikro tektonske plosce pod Evrazijsko plosco sprozilo tako imenovano Juznoalpsko narivanje. To dogajanje je dvignilo gore Julijskih Alp, predel danasnjega Bohinjskega jezera pa zaradi tektonskih razlogov ni sledil dvigovanju – nastala je tektonska udorina. Med ledenimi dobami so ledeniki to udorino dodatno razsirili in poglobili ter pripravili vse potrebno za nastanek Bohinjskega jezera.
Voda s svojo erozijsko mocjo in sposobnostjo raztapljanja apnenca, ni imela tezkega dela pri iskanju novih poti z visokogorske doline Triglavskih jezer v udorino Bohinjskega jezera. Delo je opravila podzemsko, z razsirjanjem razpok in dolbljenjem jam skozi apnenec.
DANASNJE STANJE – ZANIMIVO
Danes je Savica dvopramenski slap, a bolj tocen opis bi navajal, da gre tu pravzaprav za dva slapova. Lahko bi rekli, da je danes slap Savica v svojih najlepsih letih! Ob normalnem vodostaju visji slap izvira na nadmorski visini 836m in nizji na 790m. Na prvi pogled bi lahko mislili, da se voda visjega slapa nekje sredi stene nekako razcepi in tako nastane nizji pramen slapa. A temu ni tako! Temu pritrjuje dejstvo, da pri nizjem vodostaju cez steno tece le nizji slap. Kako in zakaj? Raziskovalci so odgovor nasli leta 1949, ko so za ustjem visjega slapa, po vodnem rovu prodrli kakih 100m v globino gore.
Vode Savice so svojo pot izdolble skozi skalo ob prelomnici, ki seka steno Komarce v smeri jugovzhod – severozahod, z nagibom prelomne ploskve priblizno 45 stopinj proti jugu. Vodni rov za izvirom slapa tej prelomnici najprej sledi skoraj vodoravno.
Precni prerezi vodnega kanala (prikazani na Sliki 2) jasno kazejo, da ta sledi prelomnici. Nedalec od vhoda v rov lezi 40m dolgo in 4m globoko jezero. Za njim je drugo, le 5m dolgo jezerce, nekaj naprej sledita se dve manjsi jezerci.
Slika 2: Jezerca so ostevilcena v smeri vodnega toka od 1 do 4; Precni prerezi so oznaceni s crkami od a do f; Crna puscica kaze smer dotoka vode; Modri puscici kazeta smer odtekanja vode skozi razpoko k nizjemu slapu; Crtkana rdeca linija prikazuje smer teknonske prelomnice.
Skica je povzeta iz knjige Slapovi v Sloveniji, Anton Ramovs, glej vir st.1: prikazan je del vodnega rova raziskanega do leta 1949; pomozne crte prerezov in oznacbo lege prelomnice dodal vane_si;
Raziskovalci so odkrili, v zadnje jezero (st. 4) ne pritece vsa, ker jo del odteka skozi odprto razpoko v dnu predzadnjega jezera (st. 3)! To razpoka je pravzaprav z vodno erozijo razsirjena prelomnica! Tako torej znatne kolicine vode uidejo iz glavnega vodnega kanala, stecejo po ploskvi prelomnice in izvirajo kot nizji slap! Vendar je razpoka preozka, da bi odvajala vso vodo pri normalnem vodostaju. Vecina vode se torej se vedno prelije v zadnje jezero in izvira kot visji slap.
Pozorno poglejte fotografiji B in C pri sliki 1: jasno je razvidno, da je kolicina vode, ki izvira v nizjem slapu v obeh primerih prakticno enaka, ceprav je vodostaj na sliki C resnicno zelo visok, in skupni pretok dramaticno povecan! Ta dejstvo se dodatno potrjuje ugotovitve, da nizji slap vso vodo dobiva iz razpok v glavnem vodnem kanalu – ki lahko odvede omejeno kolicin vode – ves presezek pa se mora preliti v visji slap!
V desetletjih ki so sledila prvim raziskovalcem, so jamarji potapljaci uspeli prodreti se precej globlje v notranjost (glej sliko 3). Preplavali so kakih 300m dolg vodni sifon in potem raziskali se nekaj rova naprej. Doslej so raziskali priblizno 560m rova od vhoda v vodni rov.
Slika 3: Prerez slapa Savica in doslej raziskanega vodnega rova.
PRIHODNOST OBETA KONEC SLAVE
V casu suse, ko je pretok vode zelo majhen, ali pa pozimi, ko zamrzne vecji del vode v povirju Savice, obiskovalci lahko za hip uzrejo prihodnost slapa Savica. S casom bo voda razsirila razpoko v dnu vodnega rova dovolj, da bo odvajala vso vodo. Geolosko gledano, se bo to zgodilo cez nekaj kratkih trenutkov! Tedaj bo nizji slap vse kar bo ostalo od danasnje velicine. Vsaj nekaj casa bo tako… a vse se nepretrgoma spreminja, ker se med mocjo erozije in gorotvornimi salami bije vecni boj.
GEOLOŠKI ZAKLAD IN DOSTOP
V toplejsem delu leta, obicajno od aprila do oktobra, je potrebno pri domu pri Savici placati parkirnino, za dostop do slapa pa vstopnino. Od parkirisca do zacetka poti k slapu ni dalec. Koordinate Geološkega zaklada so postavljene k hisici na zacetku poti. Pot je delno tlakovana in vas skozi prijazen gozd po stevilnih stopnicah v 15 minutah pripelje do lesenega paviljona z razgledom na slap. Na poti je vec kot 500 stopnic – majhni in veliki otroci se lahko zabavajo s stetjem...
Z razgledne ploscadi se obicajno spustimo po poti se navzdol, do ograje pred tolmunom. V casu visokih voda pa je vcasih prsenje vode tako mocno, da cloveka popolnoma zmoci ze, ce stopi iz zavetja razglednega paviljona!
Opomba: Poti uporabljate na lastno odgovornost! Hodite le po poteh za katere ste ustrezno pripravljeni! Zelimo vam varno pot in veliko uzitkov!
VIRI:
1. Anton Ramovs, Slapovi v Sloveniji, Slovenska matica, Ljubljana, 1983;
2. Rok Kuslan, Slapovi, Sidarta, Ljubljana, 2008;
3. Ivan Gams, Kras v Sloveniji v prostoru in casu, Zalozba ZRC, Znanstvenoraziskovalni center Slovenske akademije znanosti in umetnosti, Ljubljana, 2004;
4. Fotografija A: Karel Hinterlechner, slovenski geolog, petrolog, mineralog, filozof, pedagog; fotografija posneta okoli leta 1900;
5. Fotografija B: Stane klemenc, iz knjige Slapovi, glej vir st. 2.
6. Fotografija C: gregax, s spletne strani “pictureslovenia.com;
tocke poti in dnevniki / waypoints and logs