08 January 2025

A Sentence about the Island-wrecks in the Iron Gates

 



As the water level on the Danube is never horizontal, neither are the islands, and this phenomenon is only noticeable in cases where people interfere with the natural flow of the river, mostly for the sake of navigation, because ships and their crews do not like going against the flow, they would much rather travel on a water surface like a lake or a sea, but the Danube is not really a lake nor like a sea, and it is not right to try to make it into one, as happened west of Bős/Gabcikovo, where the Danube is almost completely dammed and climbs the steps of a series of locks and weirs, and on the river section between Serbia and Romania, where the mountains compressed the floodplain and did everything they can to make the lives of sailors miserable with their scattered boulders and reefs, so that then, as if out of revenge, the sailors made the lives of the Danube islands, and rock bars miserable, breaking and exploding many of them, sinking them and only leaving some of them untouched, because there is a section between Smeredovo and Moldova Veche, where after the construction of the Iron Gate the reservoir slowly rising from the east could not completely submerge the islands, they hang out of the tilted Danube like the worn-out barges of a stranded fleet, with their noses pointing west, and their eastern barge lies in a shallow watery grave, from which only at low tide do their wrecks, stripped of their island character, emerge, which was not dug out by human hands, there are no regular forms typical of gravel mining, artificial pools, or traces of dredging, it is simply that nature created such arm-shaped islands here, where regular floods first deposited the alluvium transported from far away along the coast of the larger islands, as in the case of river ridges on the coasts, such was the case with Ponjavica, Zavojszka, Cibuklija, Kalinovac and partly the Moldova Veche island, all of which lie like a bitten crust of bread in a certain zone of the Danube, where the place of the breadcrumbs has been taken over by waterfowl and juvenile fish, and on which man, for lack of a better word, has placed the nature conservation area sign, hoping to somewhat obscure the view of this industrial, overturned landscape, which nature is trying to sort out with its own means.

E-shaped island called Kalinovac. (googleearth)


03 January 2025

Where Does the Danube End?

MAGYARUL

This is the end, the traveller might say, as the sky widens over the Sulina lighthouse and the river becomes a seemingly endless expanse of water. But is this really the end? According to Plato, "Heraclitus says somewhere that everything is in motion and nothing remains unchanged, and comparing beings to the flow of a river, he says that you cannot step into the same river twice." To find a reassuring answer to the question of where the Danube ends, we need to travel hundreds of kilometres out into the Black Sea, more than a kilometre deep, and over millions of years in time. 

Fig. 1. The situation of the Danube (Viteaz)-canyon at the bottom of the Black Sea. (source)

It is necessary to translate the philosophical ideas of Heraclitus into the language of the more specific earth sciences. Since the Danube has existed, its parameters have been constantly changing, as they did in the early tens of millions of years, during the period of natural evolution when it was shaped solely by natural conditions, and later, in the time span of up to 10,000 years, when human influence has been increasing. The length of the river has changed, at first only the small river meandering in the Alpine foothills filling lakes and bays of the Paratethys Sea, the extent of its catchment area has changed, while its upper reaches have often been overtaken by neighbouring watercourses, such as the Rhine. This, together with changes in climate, has led to changes in discharge, for example, melting after the last glaciation significantly increased the discharge, while dry warm periods reduced it. To give specific examples, the Danube filled (with other rivers) the Pannonian lake, while the Rhine conquered a significant catchment to the west, and the increased discharge spread a huge amount and thickness of gravel material over the Hungarian section of the river, and not only has the source of the Danube changed over the millennia, but the estuary, i.e. the delta, has also migrated, and has been further west than it is today, but what is relevant for the present post is that the Danube has been moving from the river basin to the delta: further east. 

Fig. 2. The position of the Danube canyon on Google maps.

A hundred kilometres southeast of the present Danube Delta, deep-sea research has revealed a distinctive, long and deep gorge valley in the depths of the Black Sea (see Figure 2). Its official name suggests that the Danube must have something to do with it. In the north-western basin of the Black Sea, there is a relatively large shallow shelf area of 140*170 kilometres, with depths varying between 20 and 140 metres, into which four major rivers transport their sediment: the Danube, the Dniester, the South Bug and the Dnieper. The head of the canyon valley cuts deep into the rim of the continental shelf and extends down to the level of the deep-sea bed, while no distinct morphological relationship is visible between the present Danube delta and the head of the canyon valley. 

Fig. 3. Major tributaries of the Black Sea (the Dniester on the wrong place) and depth contours (source)

The head of the Danube Canyon, which cuts into the shelf area, begins at a depth of about 90 metres, and its terminus is lost 100 kilometres away on a wide fan-shaped alluvial cone, breaking up into several branches, in the deepest zone of the Black Sea, at the deep-sea floor, at a depth of about 2100 metres. By comparison, the deepest point in the Black Sea is at 2210 metres. The canyon is two kilometres wide on the section that cuts into the backshore, with steep side walls (up to 30°) and shell-shaped notches all around. The V-shaped valley, which cuts into the valley floor at a depth of 400 metres, curves from the north-west to the south-east with a steep descent on the continental slope, where the valley widens to a width of six kilometres. The distinctive valley continues as a channel on the seabed, where it branches off into a deep-sea delta of its own making. This is not a unique phenomenon, as similar deep-sea canyon valleys have been observed in other rivers, whether in the Amazon, Hudson or Congo estuaries. It would be wrong to think that this submarine geomorphology was formed by river water, so it is questionable whether the Danube ends here. 

Fig. 4. The relief of the Danube Canyon (source

It is also questionable how the Danube could have formed this deep-sea gorge, far to the south-east of its known estuary. Since fresh water cannot continue to flow down to the bottom of the sea, forming erosion trenches, once it reaches the erosion base, some other effect must be behind the phenomenon. First of all, it is worth looking at the specific characteristics of the Black Sea, which in many ways is unique compared to other seas. The Black Sea is a typical inland sea, connected to another inland sea only through a thin strait, the Bosporus, as the Mediterranean Sea is also connected to the Atlantic Ocean through a very narrow strait at Gibraltar. The Bosphorus Strait, which connects the two bodies of water, has a minimum depth of only 36.5 metres at the Golden Horn, which means that if global sea levels fall below this point, the Black Sea becomes a saltwater lake. By the way, the sea is also a unique body of water in terms of salinity, since it is a moderately saline brackish water body at the surface down to a depth of 150 metres. This layer is caused by rivers flowing into the sea with high freshwater discharge and oxygen-rich freshwater, under which there is a saltier, anoxic, lifeless layer of water, and the two layers do not mix. The lack of mixing of fresh and salt water rules out the possibility that the Danube water could be currently shaping this canyon. Nevertheless, it cannot be said that it is an inactive valley.

Fig. 5. The sediment fan of the Danube canyon (source

There is another possibility for the formation of the canyon, and that is the drastic lowering of sea level, in other words regression. Sea-level rise and fall in the Black Sea is different from similar movements in the world's oceans because of the aforementioned Bosporus threshold. The last 20,000 years provide a good example to illustrate this; at the time of the last glacial maximum (LGM), the Black Sea was most likely a fresh, or at least reduced salinity lake, which received its water from the rivers flowing into it. Its surface was about 110-120 m below present-day sea level at the time of its maximum advance from the ice sheet (white line in Figure 5), i.e. the northern shelf and the Azov Sea were dry. Water covered only the continental slope and the levels of the deep-sea plain. The three major rivers to the west of the Crimean peninsula, the Dniester, the South Bug and the Dnieper, reached the lake at this time in a common channel, while the mouth of the Danube may have been separate and south-west of it, at the head of the canyon valley. As it was a tidal stagnant water, it cannot be assumed that the Danube had a gorge-like estuary at the end of the Ice Age, and almost certainly had a delta estuary even then, which may raise further questions about its geomorphology.

The water level in the Black Lake started to rise after the end of the LGM. Meltwater from the ice sheet in the north (Scandinavia and NW Russia) significantly increased the discharge, capacity of sediment transport of rivers flowing into the lake. During the same period, the rate of the sea level rise in this basin was greater than in the Mediterranean. 13,000 years ago, the level of the Black Lake was approaching, perhaps even reaching, the lovest level of the Bosporus Strait, while the level of the world's oceans was still 70-80 metres below the present level. Some theorise that the freshwater of the Black Sea may have been tumbling through the Marmara Sea into the Mediterranean at this time. However, the rise of the lake stopped at a certain point and the water level began to fall again as the meltwater supply decreased, the waters from the ice sheet no longer finding their way down the great rivers of the Steppes, but heading for the lake that formed where the Baltic Sea once the ice dam had disappeared. 8000 years ago, the situation was almost restored, the shelf area became dry again, the lake level was -90 to -100 metres below the present level. The dry and cold climate built up dune valleys in the coastal areas from the transported sediment, and the rivers took possession of their pre-transgression bed and estuary. 

Around 8,500 years ago, the rising level of the Mediterranean Sea reached and exceeded the Bosporus threshold, and salt water flowed into the Black Lake basin. In an extremely short time, the water level rose by 70-80 metres. Many believe this to be the historical basis of the biblical flood, but it is certain that the former coastal morphology of the Black Sea, the sand dunes, the wave-lashed shores and delta area, were not destroyed by erosion, but were preserved in the deep by the rapid rise in sea level. The Black Sea was thus formed, and its level and the location of the Danube delta were fixed for thousands of years. 

Fig. 6. Changes in the Black Sea level since the LGM (source)

However, it is also important to consider whether the Black Sea level could have been lower at other times, when fluvial erosion would have had the opportunity to exert its erosive effects right down to the bottom of the steep continental slope. Several glaciation phases occurred during the Pleistocene, but global sea level fell to around -120 m in all of them, and as the Black Sea basin was in a similar position during this geological epoch, it is likely that the water level here did not change more than observed in the LGM. If we look at earlier ages, the effects of glaciation can be excluded as a possible cause, but at the end of the Miocene, during the Messinian period (5.9-5.3 million years ago), a tectonic event occurred that caused a series of successive drastic drying events in the Mediterranean basin. During the Messinian Salt Crisis, the connection with the Mediterranean Sea was interrupted and the water balance of the Black Lake turned negative, with evaporation becoming dominant. However, the extent of the sea-level fall is still a matter of debate, with seismic measurements suggesting a subsidence of several hundred metres, while paleontological studies suggest a few tens of metres. However, this regression certainly did not affect the Danube delta, which at that time was still filling the Carpathian Basin and the Pannonian Lake, and the Romanian Plain could have been a (Paratethys) bay (Figure 7). 

Fig. 7. The Black Sea basin during the Messinian Salt Crisis (source)

It follows, therefore, that the Danube canyon, hidden in the depths of the Black Sea, could only have formed towards the end of the Pleistocene, when the Danube delta extended to the edge of the continental shelf in two morphologically distinct phases, during the LGM, almost 13,000 years ago, and it is also likely that the Danube was shaping the canyon, even below sea level. However, slope mass movements, not sweetwater influx, played the main role in the formation of the canyons. The huge amounts of loose sediment transported to the steep rim of the shelf were sometimes unstable and would slide down the slope in landslides, and the lack of material would be replaced by a widening gorge due to the continuing slurry. As the sediment was constantly replenished, the slides recurred, but now at the predicted location and along the slip path. Although submarine slides and gullies can also form in places where there is no estuary, there is no marked backward movement into the continental shelf. The regular mudslides formed a channel on the self-slope and then spread out over the deep-sea plain as gravity ceases, forming a flat alluvial cone. This sediment is known in geology as turbidite, and in many places it can be studied as rock compressed into mountains. 

Fig. 9. ábra Undersead turbidity currents. (wikipedia)

Although sea-level rise and land receding have rendered the gorge valley inactive over time, and human impact (hydrolelectrical dams) has radically reduced the amount of sediment reaching the sea, further landslides may still occur at depth on the steep sides of the gorge. So this is where the Danube ends, at the bottom of the Black Sea, in a geologically very young valley hidden from human sight and its associated deep-sea alluvial cone, hundreds of kilometres from the present-day estuary.



International literature on the canyon is fortunately abundant and can be found here:


  • https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=2afea9bb0a2b98713e7ed97b7ff19ff81cffce1f
  • https://www.nature.com/articles/s41467-017-02271-z
  • https://www.sciencedirect.com/science/article/abs/pii/S0012825218306998
  • https://www.researchgate.net/publication/277775413_Evolution_of_the_Danube_Deep-Sea_Fan_since_the_last_glacial_maximum_New_insights_into_Black_Sea_water-level_fluctuations
  • http://www.blacksea-commission.org/_publ-soe2009.asp
  • https://www.researchgate.net/publication/298354387_Submarine_canyons_of_the_Black_Sea_basin_with_a_focus_on_the_Danube_Canyon
  • https://sci-hub.se/https://doi.org/10.1016/j.margeo.2004.03.003
  • https://www.britannica.com/science/submarine-canyon
  • https://www.sciencedirect.com/science/article/abs/pii/S0012821X12006565 
  • https://sci-hub.se/https://doi.org/10.1016/j.epsl.2012.11.038
  • https://sci-hub.se/10.1144/petgeo2015-093
  • https://geoecomar.ro/beta/wp-content/uploads/2021/01/02_OLARIU_c1_2020.pdf
  • https://www.sciencedirect.com/science/article/abs/pii/S0921818108001744
  • https://books.google.hu/books?id=0iXMJJQblg0C&pg=PA82&hl=hu&source=gbs_selected_pages&cad=1#v=onepage&q=canyon&f=false
  • https://ui.adsabs.harvard.edu/abs/2016EGUGA..1811391C/abstract
  • https://journals.openedition.org/mediterranee/8186

02 January 2025

The Isolation of Stadtamhof


In the summer of 1945, a US Army project sent a film crew to document everyday life in post-war Germany, obviously with a focus on the destruction of war, but sometimes with some interesting moments. At the beginning of the aerial footage of USAAF Special Film Project #186 documenting the area around Regensburg, we get a bird's eye view of Stadtamhof from the rear of a plane flying north to south, then after the famous Stone Bridge we see Regensburg and the aftermath of the devastating bombing of its railway station. At the beginning of the film, we see three unfinished pillars in a fenced-off pond, the first stage in the transformation of the town of Stadtamhof into an island on the Danube.

The pillars of the Protzenweiher Brücke in Stadtamhof, summer of 1945 
(Source: National Archives and Records Administration

At first glance, the pond appears to be an artificial structure, the work of the human hand accentuated by the half-finished pillars of a bridge that leads nowhere. The location is Regensburg's old rival, Stadtamhof, on the north bank of the Danube, originally part of Bavaria, which was only administratively annexed to the imperial city of Regensburg on 1 April 1924. In the foreground of the picture you can see the church of St. Mang and the large monastery of the Augustinian canons, which is about 1,000 years old and lies to the east of the main road forming the axis of Stadtamhof, to the south the Danube, which bypasses the Oberer Wöhrd in Regensburg, and to the east the river Regen, which gives the town its name, border the district. 

A view on Regensburg from the Winzer Hills,
with the Oberer Wöhrd in the center and, Stadtamhof to the left

Stadtamhof has always had a direct link to the Danube, as has Regensburg and to a lesser extent to the hilly area behind it, crowned by the Trinity Church of Steinweg, which towers above the Danube valley. The Steinweg and Stadtamhof were not built together until recent times, and a wide field on either side of the main street of Stadtamhof leading to the ancient stone bridge (Steinerne Brücke) in Regensburg has always been preserved on old maps. During the Allied air campaign during the Second World War, this area was a fairground (Dultplatz), where town fairs were held. These fairs flourished especially from 1875 onwards, when the mayor of neighbouring Regensburg banned them, often covering the whole of the main street in Stadtamhof. There was, however, an older, more colloquial name for the area, which, as opposed to the socio-geographical name, refers to the environment in which this fairground was established at the time, and which was retained by the town planning in the name of the bridge that was later built; Protzenweiher, i.e. an area of water (Weiher) where toads (Protzen, or Brotzen) lived.  

The still existing creek north from Stadtamhof on a western oriented map from 1797.
(Source: mapire.eu)

From a geomorphological point of view, this area was probably originally a branch of the Danube, which may have been filled by the late Middle Ages (Hochmittelalter), and archaeological evidence of this has been found. In other words, Stadtamhof was founded on a high plateau, on a flattened island in the Danube, bordered by the Danube to the south and a low marshy floodplain to the north. The geomorphology of the area is illustrated in the following picture, taken in 1970 during a Danube flood on Stadtamhof's main street, looking north towards the church of Steinweg (with the Regensburg Cathedral to the south). The foreground of the picture is higher up, with cobblestones visible, while the area also slopes down towards the north. The Protzenweiher was recorded as being frequently flooded by the Danube, and the water remained in the form of lakes and ponds for a relatively long time, filling in the lower-lying areas, and in winter it also served as a natural skating rink. These floods caused serious disruption to navigation on the Danube, as the arches of the Stone Bridge blocked the river in its entire section, making it impossible for boats to cross underneath, while the Protzenweiher was also blocked in the other direction. 

Flood in Stadtamhof in 1970 with a view towards Steinweg. (Source

It is not only east-west traffic that has been disrupted by the floods, but also north-south traffic. In 1784, the road between Stadtamhof and Steinweg was the victim of a major flood on the Danube, and it is important to note that it was not a bridge but a brick embankment, although it was known locally as a bridge (Waisenhausbrückl). The remains of two older similar crossings were found when excavation work began in March 1973 on a new shipping route through the Protzenweiher field, known as the Europakanal. A bridge may have existed here before, but it is certain that when the Stone Bridge was built in 1146, spanning at least two, but more likely three, branches of the Danube, it was not considered necessary to build a bridge over the Protzenweiher branch, the embankment, on which there was almost certainly some kind of culvert to allow the higher water levels to pass. This culvert can be seen on the 1797 map section above. Soon afterwards, this culvert disappears from the maps, as during the Napoleonic Wars, Stadtamhof, which had no fortifications, suffered serious damage, with large parts of the town burnt down by cannon fire from French and Austrian troops. The ruins of the burnt buildings were not taken far, and the nearby Protzenweiher was filled in. This anthropogenic accumulation of 'sediment' is thought to have been constant throughout history, and may have accelerated in times of war.

Stadtamhof in 1943. Source: GoogleEarth

By the 20th century, the increased volume in shipping on the Danube meant that Regensburg's famous Stone Bridge became more and more of an obstacle to river traffic, and Regensburg became the terminal port for international Danube shipping, as larger cargo ships could not fit between the thick pillars. However, the eight-century-old bridge, the symbol of the city, was not to be dismantled for such prosaic reasons, and an alternative route for the ships had to be found. The free space between Stadtamhof and Steinweg was a perfect choice, where no buildings had to be demolished to make way for a new canal, and the only thing that was needed was a new site for the market square. The construction of the canal had already begun in the 1930s with the dredging on the Regen river, and between 1939 and 1940 the piers of the new bridge were completed, but for some reason they were not placed on the route to the Stone Bridge, but a street to the east, where some buildings would have had to be demolished, but were still standing in 1945. Construction was halted by the outbreak of the Second World War, but the steel structure of the Protzenweiher Bridge was completed by 1953, but the lock was not built and the unfinished bridge stood unused for 15 years. 

The almost finishec Canal in July of 1974. (Source: Bundesanstalt für Wasserbau)

The next "first step" of the Europakanal construction was made in March 1973, and at the same time the Regensburg hydroelectric power station was built further west, at the western tip of the Oberer Wöhrd, and started to operate in 1977, the year before the canal was completed. Its dam raised the Danube level by 4.7 metres, swelling the river for 21 kilometres. The canal's 12-metre-wide lock may not seem large, but it provides a bypass for the Danube-Main-Rhine canal traffic, allowing shipping to bypass Regensburg.

The different levels of the Europakanal (left) and the Danube (right)

The Stadtamhof district gradually lost its through traffic, with the Nibelungen Bridge, opened in 1936, playing a major role. On 3 May 1978, it officially became an island in the Danube, accessible only by bridges. In total, there are seven bridges leading to the island, but four of them are pedestrian bridges, including the Stone Bridge, from which car traffic was first banned in 1997 and then, after the World Heritage Site was awarded, buses and taxis from 1 August 2008. The decision to turn one of the 'main streets' of world history into a pedestrian thoroughfare was taken in recognition of the serious damage to the structure of the historic bridge caused by the 1903-1945 tram traffic and heavy vehicles. The Protzenweiher Bridge was, however, built at the eastern end of the lock chamber, right where the US Army had filmed the foundations in 1945. After 1972, the fairground (Dultplatz) was moved east of Stadtamhof, and today this concrete parking lot makes up the entire western part of Stadtamhof Island.  

The lock of the Europakanal in Stadtamhof

Today, around 6000-7000 ships pass through the lock each year. However, the tower at the eastern end of the lock chamber is empty and the lockkeepers have moved away as the system is operated remotely. This tower was built symmetrically, as it was always planned that there would be a second canal and lock. But this never materialised in the end, and probably never will, as the toadfrog swamp has since been built up to the sluice on both sides. 

Translated with DeepL.com (free version)

08 October 2024

Chiar n-a văzut nimeni când s-a rupt stânca Babacaia?


Stânca Babacaia la 1963, forografie făcuă dinspre partea de nord-est (Fortepan / Nándor Drobni)


Stânca Babacaia este parte dintre cele mai marcante peisaje dunărene. Voit nu o numesc insulă, pentru că se deosebește deplin de imaginea generală creata insulelor dunărene. Dar atunci ce este? Este un grind? Este o stâncă? La urma urmei nici nu contează, ceea ce contează mai mult este că mulțumită poziției sale speciale dispune de o bine documentată arhivă de imagini, unele chiar cu mult dinainte de apariția tehnicii fotografice. Dacă ne apucăm să analizăm în ordine cronologică imaginile cu stânca putem observa un fapt interesant. Parcă în prezent ea pare mai scundă și mai puțin groasă. Prima remarcă se explică ușor prin ridicarea nivelului apei odată cu construcția hidrocentralei Porțile de Fier I., Dunărea a acoperit „trena” din sudul grindului, dar ce s-a întâmplat cu masa principală a stâncii, care în trecut se prezenta cu capătul despicat în două vârfuri din care azi se mai vede doar unul?

Stânca Babacaia fotografiată de la Coronini (cetatea Sf. László), adică de la est.

În mare parte inofensiv (citez titlul volumului lui Douglas Adams din 1992) – puteau spune navigatorii despre stânca Babacaia. Se prezintă ca un deget aratător ridicat deasupra apei, care atrage de departe atenția asupra pericolului la care pot fi supuse ambarcațiunile (44.672954, 21.677079). Sunt, adică mai bine zis erau, grinduri incomparabil mai pericuolase pe Dunăre, ascunse direct sub luciul apei, dar acestea au fost desființate, împreună cu multe altele, de destul de drastica reglementare regională a albiei fluviului. Stânca Babacaia, împreună cu ruina cetății Sf. László și cu ceva mai bine păstrata cetate Golubovăț păzesc în trei acest segment al Dunării, unde din ambele maluri se înalță dealuri direct din fluviu. Aceste repere de lângă Babacaia ajută la identificarea exactă a situației, bunăoară stânca este în fluviu, se poate naviga de jur îmrejurul ei și din această cauză imaginile cu aceasta sunt executate din varii direcții. Pe unele imagini poate apărea și cu reflexie în luciul apei, multiplicând senzația de distorsiune în spațiu.

Vârful actual, singular, al stâncii Babacaia, fotografiat din partea de est.

Masa calcaroasă a singuraticei stânci Babacaia s-a transformat din sedimentele acumulate în marea jurasică în rocă carbonatică. Dimensiunea ei trebuie să fi fost inițial mult mai mare dar a fost îmbrățisată de Dunăre și a fost supusă forțelor externe ale vântului, ale apelor pluviale, ale procesului de îngheț/dezgheț, și astfel suprafața calcaroasă s-a corodat în timp. Literatura care face referire la stâncă menționează în general că în perioada romană sau turcă putea găzdui un turn de veghe, dar este mai degrabă neverosimil întrucât militarilor postați aici ar fi trebuit să li se asigure constant proviziile. Locul nu dispune nici măcar de apă curată, dar mai presus de asta, din cauza dimensiunii reduse, stânca ar fi devenit mai degrabă închsioare pentru ei. Suprafața actuală se încadrează aproximativ într-un cerc cu diametrul de 15 metri, în funcție de nivelul apei, suprafață care înainte de înființarea lacului de acumulare varia puternic. La nivel scăzut al apei, la sud de stânca principală, adică în direcția sensului de curgere a fluviului, se prezenta un mal de piatră unde se putea debarca foarte ușor, mai mult decât atât, conform imaginilor vremii, se înrădăcinaseră o serie de arbuști, dar cel mai probabil aceștia erau nevoiți să existe în condiții deosebit de vitrege. 

Ruptura proaspătă fotografiată dinspre nord.

Babacaia  se poate escalada cel mai usor din partea din vest, aici avem cea mai domoală pantă, dar și aici înclinarea este de minim 60 grade, față de partea nordică și estică unde stânca iese aproape vertical din Dunăre. Aceste două fațete ale stâncii se disting însă cu usirință. Partea dinspre est este afectată de intemperii, acoperită de pete, în mai multe locuri s-au înrădăcinat mușchi și licheni în timp ce partea de nord pare aproape netedă prin comparație. Din punct de vedere geologic vedem aici rocă proaspătă, ceea ce dezvăluie evident o suprafață de rupere recentă, unde forțele externe încă nu au reușit să își lase amprenta. Starea geologică indică evident prăbușirea recentă a stâncii, ceea ce este evidențiat și de imaginile pe care le avem la dispoziție. Existența vârfului bifurcat al stâncii Babacaia este evidentă și până pe la mijlocul secolului XX. În pofida faptului ca este un secol destul de bine documentat și chiar mai mult de atât, construcția hidorcentralei a concentrat o atenție deosebită în zonă, nu am putut afla când și de ce a dispărut coloana nordică a stâncii.

Stânca Babacai cu mitră, fotografiată din partea de sud. Kajtor I./MTI

Cert este că, în luna august a anului 1969, cele două vârfuri ale Babacaiei încă au putut fi fotografiate de Kajtor I. iar imaginea a putut fi publicată în Buletinul Hidrologic. Pare plauzibil ca stânca să se fi prăbușit în lacul de acumulare deja existent. Din păcate nu am putut descoperi când s-a întâmplat asta. În prima imagine, cea din 1963, se poate bănui deja o crăpătură lată, între vârful bifurcat si până la bază. Posibil că celălalt vârf să se fi surpat din cauza lucrărilor de la hidrocentrală, ori din cauza ridicării nivelului apei, ori din cauza înghețului, eventual niște turiști neatenți s-au aventurat prea mult pe el, ori cine știe, cineva a dorit sa cioplească și aici figura unui dac. Cineva trebuie să fi observat totuși… mai ales că pe unul din vârfuri era si panou de semnalizare pentru navigație. În orice caz există speranță că s-a documentat surparea și în articolele de presă din limba românâ și undeva, cineva, cândva, va da peste această informație nu prea importantă.

Mulțumiri lui Attila Gyulai pentru ajutor și traducere!

28 August 2024

Picturesque Danubian Photochrom Collection


6336. Wien, Franz Josefs Kai, the Donaukanal is visible on the right side with the overarching Salztorbrücke. 


Photo? Postcard? A painting? It's hard to know exactly which category the images from the Zurich-based Photoglob AG (originally Photochrom Zurich) series of images of Europe and, to a lesser extent, North America fall into. The Zurich-based company was founded by the Orell Füssli Institute of Arts and used lithographic printing techniques to produce colour images from black and white photographic originals, a process developed by the Swiss lithographer Hans Jakob Schmid. Between 1896 and 1906, the company published a monthly magazine in French and German language, featuring their new images. Printing rights were also sold abroad, for example to the Detroit Publishing Co. The company's prosperity came to an end when demand for such pictures fell during the First World War. 

What is certain is that the ink-based photolithographs, which depict nearly six thousand locations, are easily distinguishable from contemporary photographs, postcards and landscapes, whether it is Ragusa in Dalmatia or Königsberg in eastern Prussia, by their colours and gold lettering. These pictures were reproduced and sold as souvenirs all over the world, each with a unique serial number. 

They depict in landscape detail the characteristic features of a settlement or landscape (mountain, valley, river, gorge, coast, etc.), often capturing street scenes and everyday life. The collection of the US Library of Congress includes a large number of images of the Austro-Hungarian Empire, although fewer of them are of the Hungarian territories. The Western provinces and Dalmatia are well represented, but there is also a fine series on the Danube Valley, which, as far as I know, no one else has collected. 

From Engelhartszell to the island of Ada Kaleh, covering 1250 river kilometres of the Austro-Hungarian Empire, the collection contains a total of 24 pictures, of which 15 are for the Austrian section and 9 for the Hungarian section. Most of them are urban views, but there is also a strong emphasis on castle ruins, and even a few Danube islands, the value of which lies in the fact that most of them have been eradicated by river regulation. There is no doubt that we are looking at a series of documents, which are arranged in the following order, downstream on the Danube:

9214. Engelhartszell, 2201 river kilometer (rkm). A view on the Austrian town, from the former ferry crossing, which was not far from the Dandl creek, representing the German border. From here downstream, both sides of the Danube belong to Austria.

9218. Ottensheim, 2145,5 rkm. Panorama of the Ottensheim castle from the opposite side, Wilhering. The former Habsburg castle is private property nowadays, since the picture was taken, the castle got a new tower.

1731. Linz, 2136 rkm. Outlook on Linz from the west, presumably from the Franz-Josefs-Warte. The huge building in the middle of the picture is the Castle of Linz, next to it the Nibelungen bridge overarches the Danube to the northern suburb Urfahr Beyond the bridge there we see the former forested Strasser Island.

9212. Grein, 2079 rkm. The castle of Grein has been build on a granite cliff over the Danube at the entrance of the Strudel gorge, an old adversary of the shipmen of the Danube. Greinburg is now a property of the House of Saxe-Coburg and Gotha, between its walls there is Maritime Museum.

9207. Wörth and Werfenstein, 2077 rkm. The wild Strudel gorge-szoros has been tamed by a hydroelectrical power plant, which raised the water level on the upstream reservoir, reducing the relative height of the steep cliffs, crowned by the castles of Wörth and Werfenstein.

9219. Persenbeug, 2060 rkm. "Patrick Leigh Fermor has arrived exactly 80 years ago, in late January, 1934 to the Austrian town Persenbeug. After having supper in the town inn and filling his journals for the day he made a sketch of the innkeeper's daughter. And he's been talking to an old polymath aristocrat till late night. About the Danube, its fish, especially the catfish, the kraken of the Danube, about hydroelectric dams, Romans, Markomanns, archaeology, flora and fauna, about Hans, ritter of Ybbs, the Tartars, Schubert, Wagner and about the Dodo bird of Mauritius." "Progress" altered much the landscape since then, the author of the picture would stand today underwater in the locks of the Ybbs-Persenbeug dam, on the exact same place.

9211. Marbach and Maria Taferl, 2050 rkm. Maria Taferl, with 291 inhabitants, is a famous place in Austria, its church was built next to a roadside sanctuary to the Virgin Mary between 1660 and 1710 and has since dominated the Danube. It is Austria's second largest and most important pilgrimage site after Mariazell. The picture was taken near Wallenbach on the right.

9224. Weitenegg, 2039 rkm. This castle ruin has a sad history, having fallen into disrepair in the 1700s, but the eastern part was demolished to expand the local ultramarine blue dye factory. On the far right bank is Melk Abbey, with several Danube islands in the foreground, the largest of which is Weitenecker Au, which ends to the right of the castle tower.   

9223. Schönbühel, 2032,5 rkm. Monastery and castle dominate the two cliffs over the Danube north of Melk in the Wachau. Despite river regulation works, if not an island, then by some miracle a large rocky reef still juts out in the middle of the river below the distinctive towered castle, which is still inhabited by an Austrian noble family. 

9226. Spitz a. d. Donau, 2019 rkm. Perhaps Wachau's most famous vineyard, the Tausendeimerberg, rises terraced above the town, where the main grape varieties are Riesling and Neuburger, the latter a cross between the local speciality, red Veltelini and green Riesling. The "Austrian Danube bend" is also famous for its apricots, which are sold in almost every form from dumplings to brandy. Behind the "Thousand bucket hill" you can see the ruins of Hinterhaus castle, at the foot of which the Danube bends eastwards. 

9217. Dürnstein, 2009 rkm. The "Dry Rock" is one of the iconic spots in Wachau in Lower Austria. It was here that King Richard the Lionhearted of England was imprisoned, and for four winter months he could watch the Danube flowing below him, before the ransom he paid was used to launch Ostmark's largest infrastructure development. 

9222. Greifenstein, 1949 rkm. The fact is that the Danube below Greifenstein no longer looks like this, and here too the river has been turned into a canal by the river regulation works, destroying 99% of the islands in the Tulln Danube basin. The Greifenstein castle is still there, privately owned, and is being renovated. 

6441. Wien, Kahlenberg (in the back) and the Leopoldsberg (in front), 1936 rkm. The village of Kahlenbergerdorf can be seen between the two hills, from the Schwarze Lacken Au opposite (now completely built up Au). The village is now part of Vienna's 19th district, but has nevertheless avoided urbanisation largely due to its topography. If you were to look across to the other side today, the artificially shaped, elongated Danube island would largely obscure everything. 

9210. Hainburg, 1884 rkm. View of the town from the Weisser Thurn Haufen on the other side of the river. Between the parish church of Philip and James and the huge building of the old tobacco factory, which closed in 1964, rises the Hainburg hill, mentioned in the Nibelungenlied.

9216. Dévény/Theben/Devín, 1880 rkm. View of Devín to the northeast, from an island in the Danube, half of which belonged to Austria and the other half to Hungary. The column of the Hungarian Millennium Monument is not yet visible, so the picture must have been taken before 1896.

9205. Pozsony/Preßburg/Bratislava, 1869 rkm. View from Pozsonyligetfalu/Engerau/Pertzalka. The castle, which burnt down on 28 May 1811, presumably set on fire by the soldiers stationed here, towers above the crowning temple of numerous Hungarian kingsn. It is not known whether the Franz Joseph Bridge, which was opened in 1890, was already standing at this time, as the picture was taken to the west of the bridge. 

9215. Esztergom, 1718 rkm. The Castle Hill of Esztergom with the Basilica, the ship bridge below and the northern, urbanised tip of the Prímás Island. There is no evidence of the construction of the Maria Valeria Bridge, so the picture must have been taken before 1894. 

9203. Visegrád, 1694 rkm. A well-known view of the Salamon Tower and Visegrád Citadel from near the Nagymaros crossing. To the left is Sibrik Hill, the ancient roman Pone Navata fort, but unfortunately the northern tip of Szentedrei Island is just missed. 

9213. Vác, 1678 rkm. The picture was probably taken in the Bolhavár (Flea fort, a common Hungarian name for roman watchtowers) area, on Szentendre Island, opposite the Hétkápolna (Seven Chapels), with a view of the five downtown churches of Vác, with the main mass of Nagyszál as a background silhouette. Unfortunately the Pokolcsárda (Hell's Inn) or the Vác ferry didn't appear on the picture, but let's not be insatiable.  

9613. Budapest, 1646 rkm. View from the Castle District of Buda, from the area of Matthias Church towards the south. It is most likely that the picture was taken in 1895 or 1896, as the Fisherman's Bastion has not yet been built in the picture, it was started when the Ferenc József Bridge was already standing. 

16531. Orsova, 955 rkm. Interestingly, unlike many larger Hungarian cities, the border town of Orsova has two pictures in the collection. They were taken from two different locations, on the Serbian side, on the hillside above Tekija. In this picture you can see the town's ship harbour and a detail of the Cerna Valley (right).

16530. Orosva, 955 rkm. Visszapillantás Jeselnica és Ogradena felé, azaz keleti irányban, Orsova filmdíszletnek felhasználva lerombolt és vízzel elárasztott központi és nyugati városrészeivel. A look back towards Jeselnica and Ogradena, and Orsova eastwards, which latter was demolished as a film scene of a Romanian II. World War movie, before the ruins were completely flooded. 

16532. Ada Kaleh, 950 rkm. Although the famous Turkish Danubian island of Ada Kaleh was not officially part of the Austro-Hungarian Monarchy at the time, we conclude this series with this picture. In the distance, the Danube winds its way between the Serbian and Romanian river banks, slowly emerging from the mountain range where ther river is much more Ister than Danubius onwards.


The link to the complete collection on the Austro-Hungarian Monarchy: https://www.loc.gov/search/?q=views+of+the+austro-hungarian+empire&sp=1

Translated with DeepL.com (free version)

24 August 2024

Has Anyone Seen The Babacai Rock Crack?


The Babacai Rock in 1963, photographed from the northeast (Fortepan / Drobni Nándor)


The Babacai rock is one of the most prominent places on the Danube. I would deliberately not write island, as it could not be more different from the general concept of islands in the Danube. But then what is it? A reef? A cliff? In the end, it doesn't matter, the point is that, due to its characteristic position in the Danube, there is a particularly well-documented visual representation of it, even from before the time of photography. If you start to browse through the images of the rock from the past to the present, you will notice something interesting. It is as if today it appears both lower and thinner. The obvious explanation for the former is the dammed reservoir effect of Iron Gate I hydroelectric power plant. The raised level of the Danube covered the lower parts of the cliff, a rocky reef that gradually descended towards the south, but what happened to the main mass of the cliff, which used to have two distinct peaks, only one of which is visible today? 

The Babacai rock seen from the Romanian (eastern) side of the Danube.

Mostly harmless - the h̶i̶t̶c̶h̶i̶k̶e̶r̶s̶ sailors of the Lower Danube might say of the Babakai rock, since it is like a raised index finger, towering above the water, signalling the danger lurking ahead (44. 672954, 21.677079). There are, or were, much more treacherous reefs on the Iron Gates, hiding just below the water's surface, but these have been eradicated, along with many others, by regional, somewhat drastic river regulation. The Babakai rock, with its ruined Coronini Castle and the slightly better preserved Golubac, are the trio that guard the section of the Iron Gates gorge where mountains now rise on both banks, right next to the river. These points along the Babakai help to identify its exact position, as the cliff stands in the river and can be navigated around, so typically pictures of it are taken from very different directions. In some photographs it may even appear to be reflected, adding to the spatial uncertainty.

The Babacai rock's single peak photographed from eastern direction.

The limestone mass of the lonely Babakai rock has been transformed into carbonate rock from sediments accumulating in Jurassic seas. Its size may originally have been much larger, but since it was surrounded by the Danube for a long time, it has been constantly eroded by the wind, water, ice and precipitation, and its limestone surface has been eroded and weathered. Most literature on the rock mentions that in Roman and Turkish times it may have been a watchtower, but this is highly unlikely, as the soldiers stationed here would have had to constantly transport supplies, as there is no clean water, and the size of the rock would have made it more of a prison. Its current footprint is the equivalent of a circle about 15 metres in diameter, depending on the water level, which fluctuated a lot more before the construction of the dam. At low water, a flat rocky outcrop emerged to the south of the main mass of the cliff, i.e. downstream, where it was possible to land from a boat and, according to contemporary pictures, trees and bushes could settle, although they probably had to live in very harsh conditions. 

The fresh surface of the crack photographed from the north.

From the west, it is worth climbing Babacai, this side is the least steep, although it also has a slope of at least 60 degrees, while the northern and eastern sides of the cliff rise almost vertically from the Danube. However, these two stone walls are easily distinguishable to the naked eye. The eastern face is weathered, mottled, with several areas of vegetation, mosses and lichens, while the northern face is almost smooth, with geologically intact rock, clearly a fresh fracture surface, not yet ready to be eaten away by the iron teeth of external forces. The geological condition of the rock clearly shows that it has been rock-cut, as confirmed by the photographs available to us. The double peaks of the Babakai rock, which can be seen in postcards and photographs, was clearly still there at the turn of the 20th century. Despite the fact that it is a fairly well documented century, and despite the attention paid to the area due to the construction of the power station, it is not clear when and why the northern rock pillar disappeared.

The double summit of the Babacai rock, seen from the south. Kajtor I./MTI (source)

What is certain is that Kajtor I. was able to photograph the two peaks of Babakai in August 1969 and the picture could appear in the Hydrological Bulletin, so it seems that the unstable rock had already collapsed into the newly created reservoir. Unfortunately, I have not been able to find out the exact date. In any case, the first photo of this post, taken in 1963, shows a wide crack between the two peaks, running down to the base of the cliff. It is possible that the second peak collapsed during work on the power station, or that it was cracked by rising water levels or ice, or that careless tourists ventured too far, or that someone wanted to carve a portrait of a Dacian prince. Someone must have noticed... if there were navigation signs on one of the peaks. In any case, there is hope that Romanian-language newspaper articles documented the rockfall and that someone, somewhere, will stumble across this perhaps not-so-important piece of information. 

Translated with DeepL.com (free version)