Baron Nopcsa: More than just Transylvanian dinosaurs

The publication of Balaur bondoc has generated a lot of responses by the palaeo - dedicated geoblogosphere, nevertheless it's only a preliminary last chapter in the long and intriguing exploration of the geology and palaeontology of the former cretaceous islands of Hateg, now Romania.

Dealing with the history of scientific research of this area one man must be remembered.

Ferenc Baron von Felsö-Szilvas Nopcsa was born May 3, 1877 in the residence of the family Nopcsa near the Hungarian village of Szacsal in Transylvania (today western Romania).

Fig.1. Baron Nopcsa, figure from Wikipedia.

It was in 1895 when his younger sister, Ilona, discovered some petrified bones on the family estate Szentpeterfalva (Sânpetru) and brought it to Nopcsa to determinate it. This discovery raised the interests of young Nopcsa for palaeontology, and in the same year he showed the fossils to Eduard Suess, professor of geology in Vienna, who identified it as dinosaur bones and proposed Nopcsa to excavate and study them. Asked by Nopcsa for advice and literature about the subject of dinosaurian osteology, Suess replied "Study it!"

Fig.2. Lithological sequence of the fossiliferous sites near Sânpetru, the type-locality of Nopcsa's "Szentpeterfalva / Sânpetru sandstone", from where most of the specimens he collected came (figure from GRIGORESCU 2010).

Thanks to the wealth and influence of the family, especially the personal connections of his uncle Franz von Nopcsa to the royal court of the Austro-Hungarian Empire, Nopcsa enjoyed his formal education in Vienna, and in 1897 enrolled in geology, where he studied by Eduard Suess.
June 22, 1899 he presented the first part of a planned 5 volume comprising monographic work of the "Dinosaurs of Transylvania".
Geology and palaeontology professors were impressed by the appearance and work of the 22-year old student, but also displeased by his arrogant behaviour, especially when he noted to Louis Dollo how outstanding and important his work was considering his youth.
Nopcsa concluded his studies in 1903.

Nopcsa's was described by contemporaries being a complex and contradictory personality: sophisticated and cosmopolitan, dedicated to geology and palaeontology and to his friends, even letting others publish on material he possibly couldn't study by itself, prepared to solve a problem at every cost ignoring limitations or rules, on the other side self confident, even sniffy, convinced by his superiority, always vacillating between frenetic work-mania and complete lethargy.
Nopcsa was open to new ideas and unusual methods and willing to adopt them to improve palaeontology. He combined modern concepts of biology with palaeontology to describe fossils as living organisms, a method which he recommended to the "geologist, which intends to study vertebrate palaeontology without zoological or physiological knowledge."

Fig.3. Drawings of the bone structure of Palaeohatteria (left) and Pantelosaurus (right) in a letter by Nopcsa to Friedrich von Huene, August 15, 1925 (figure from KUBACSKA 1945). Both genera belong to Synapsida.

Nopcsa studied intensively the unusual dinosaurs of the cretaceous formations of the Hateg Basin - at a meeting in Vienna in November in 1912, and subsequent publication 1914, he proposed a model in which he considered the discovered fossils of reptiles and especially the dinosaurs peculiar forms adapted to an insular environment: "while the turtles, crocodilians and similar animals of the Late Cretaceous reached their normal size, the dinosaurs almost always remain below their normal size."
He interpreted the low biodiversity of the fauna, the basal phylogenetic position of the species and the reduced size seen in dinosaurs as a results of the isolation on the islands. This phenomenon, known also from the fossil mammals of the Mediterranean islands and later summarized as "island rule", was at these times (and still is) under scrutiny and discussion.

Maybe reflecting his contradictory personality, he not only developed the idea of dwarf dinosaurs, but also an explanation of the gigantism of some other dinosaurs. In 54 pages divided in three articles, entitled simply "About dinosaurs", he proposed the overdevelopment of the hypophysis gland as cause of the overgrown proportions of dinosaurs, bringing them finally to extinction. Despite this cause seems today reasonable or not, it shows the application of Nopcsa ´s principle to fossils, trying to interfere physiological functions of an organism by observing his mortal remains, Nopcsa therefore can be considered one of the first palaeobiologists.

In 1925 Nopsca was awarded with the position of director of the Royal Hungarian Geological Institute, despite a illness that forced him for one year to stay in bed, he worked incessantly, and published on a large variety of geological themes, comprising regional geology, stratigraphy and tectonic of Albania.

In his first work on tectonics he sustained the new theory of plate tectonics, but without even mentioning the name of Wegener. In a letter later send to Wegener he noted:

"Meanwhile, I would congratulate you for the confirmation of your drift hypothesis by Tu Toit, and I am glad to be one of the initial supporters of your hypothesis."

In disagreement with an initialized drill project he quit the work in the Geological Institute in 1928.

Five years later, in Vienna, he will shoot first his secretary, friend and paramour Elmas Doda Bajazid in the head before committing suicide.

Bibliography:

BENTON, M.J.; CSIKI, Z.; GRIGORESCU, D.; REDELSTORFF, R.; SANDER, P.M.; STEIN, K. & WEISHAMPEL, D.B. (2010): Dinosaurs and the island rule: The dwarfed dinosaurs from Haþeg Island. Palaeogeography, Palaeoclimatology, Palaeoecology 293: 438 - 454
CSIKI, Z. & BENTON, M.J. (2010): An island of dwarfs - Reconstructing the Late Cretaceous Haþeg palaeoecosystem. Palaeogeography, Palaeoclimatology, Palaeoecology 293: 265 - 270
FICHTER, J. (2010): Franz Baron Nopcsa: Paläontologe, Geologe, Ethnologe und Politiker. Fossilien Zeitschrift für Hobbypaläontologen Heft 2 März/April: 100-105
GRIGORESCU, D. (2010): The Latest Cretaceous fauna with dinosaurs and mammals from the Haþeg Basin - A historical overview.Palaeogeography, Palaeoclimatology, Palaeoecology 293: 271 - 282
KUBACSKA, A.T. (1945): Franz Baron Nopcsa. Ungarisches Naturwiss. Musum, Budapest.

The Dolomite Mountains and the Dolomite Problem

Diedonnè-Silvain-Guy-Tancrede de Gvalet de Dolomieu, born June 23, 1750 in the village of Dolomieu, was a typical naturalist of his time. With 26 years he travelled trough half Europe, he got interested in the mines of the Bretagne and the basaltic plateau in Portugal, and he visited South Italy to study the aftermath of an earthquake in Sicily and observed an eruption of the Aetna.
In 1789 during a voyage to Italy with his student fellow Fleuriau de Bellevue he also travelled trough Tyrol. In the Brenner Pass area and between the cities of Bozen und Trento he noted a rock similar to limestone, but which showed no appreciable effervescences with acids. He published these observations in July 1791 in a letter to the "Journal of Physique".
Nicolas de Saussure, son of the Alpinist/naturalist Horace Benedict de Saussure requested some samples to analyze it. After some tentative denominations like "Tyrolit" or "Saussurit" in 1792 de Saussure published the "Analyse de la Dolomie" in the "Journal of Physique".
Even if the rock itself was not completely unknown, in fact called "Spat" or "Perlspat" by miners, it was not realized until the publication of Dolomieu that the rock was composed of a peculiar Ca-Mg carbonate. The Italian naturalist Giovanni Arduino (1713-1795) published in 1779 his observations about a peculiar limestone, found in the mountains surrounding Verona, but he didn't delve further into the subject and consider the idea of a new mineral.
So the name "Dolomite" became soon established, and in 1794 Richard Kirman introduced the Dolomite as a new mineral; the name from there became used to name the dolostone rocks and finally gave the Dolomites their actual name.

In the 19th century the genesis of both the Dolomite Mountains as the rock forming them became a major problem in geology. One of the most important achievements' was the recognition that the outstanding peaks and mountain groups are remains of ancient carbonate platforms and coral reefs.
In early days of geology less was known about the bottom of the sea and sedimentation occurring in oceans, only in 1842 Darwin formulated a first hypothesis dealing with the formations of tropic reefs.
Influenced by this model, intensive field mapping was carried out, and in 1860 the German geologist Ferdinand von Richthofen (1833-1905) recognised as first the Schlern Mountain as a slope of an ancient reef and other peaks as the remnants of large carbonate platforms.

Fig.2. In Leopold von Buch´s work "Esquisse d´une carte geologique de la parte meridionale du Tyrol" (1822) the author distinguishes carbonatic (light blue) from dolomitic rocks (dark blue).

After geologists could answer how the most spectacular rock walls and peaks in the Dolomites formed, the next urgent questions was if dolomite was a primary product of marine deposition or a secondary product of alteration of common limestone.

An insight to the problem came from the study of a characteristic geological formation in the Dolomites and its depositional environment: The appropriately denominated Hauptdolomit, the "main dolostone" formation, was defined in the Bavarian Alps by VON GUEMBEL 1857, and introduced in the stratigraphic nomenclature of the Alps in 1876 by LEPSIUS.

Fig.3. Example of Hauptdolomite forming steep rock walls, the Sass dla Crusc (Hl. Kreuz Kofel) 2.907m (with locals).

During the Upper Carnian and the Norian stage (216,5 - 203,6Ma) the Tethyan Sea experienced various regression and transgression phases.
The changing sea level resulted in the development of large water covered carbonate platforms or emerged tidal flats, on which a sequence of homogenous, meter thick carbonate muds with rare fossils (subtidal facies) and laminated bacterial mats and dolomite marls (peritidal facies) were deposited.
These deposits are widely distributed in the Eastern Alps, they can be found in the Southalpine unit (here denominated Hauptdolomit/Dolomia Principale Formation), as well as in a very similar development in the entire Austroalpine unit (Hauptdolomit-Gruppe in the Northern Calcareous Alps, Ortles nappe, S-charl nappe etc.) and in the Apennines and Dinarides, and therefore points at an enormous extension of this tidal sea.

During sea level low stand the muddy flats were colonized by algae and a species-poor faunal community, dominated by gastropods (Worthenia confabulate) and bivalves (Megalodus). Dinosaurs roved through the tidal flat, their tracks have been preserved at some locations. In times of emersion only thin mud layers were deposited by storms, which themselves were colonized by algae and bacterial mats, and which dried out repeatedly.

Fig.4. Detail of the Hauptdolomit - Formation showing algae / bacterial mats.

The extreme shallow water conditions continued uninterrupted throughout the whole Norian. The uniform and slow subsidence of the basement led to deposition of an up to 1.000 meters thick succession of homogeneous cycles of the two facies.
The top of the Hauptdolomite, and the end of the platform succession, is characterized by the development of polycyclic paleosols up to 30m thick, reflecting a major eustatic sea-level fall. One of the most intriguing differences of the Southalpine Hauptdolomite to other corresponding formations is the lack of intraplattform basins, with a succession of dark dolo- and limestone's, found for example in Lombardy and Austria. This fact is explained by missing tectonic activity during the Triassic in the area of the future Dolomite-mountains.

With this proposed reconstruction, geologists tried to find an actual and comparable environment to understand the deposition of dolostone: the large carbonate platform of the Bahamas Bank seemed to fit perfectly the prerequisites: a vast area covered with a shallow, tropical sea, with sparse islands and coral reefs surrounded by large tidal flats - there was only on problem: no or only a limited formation of dolomite is today observed in this environment.

The Dolomite Problem was still unsolved.

To be continued…

Bibliography:

BERRA, F.; JADOUL, F. & ANELLI, A. (2010): Environmental control on the end of the Dolomia Principale/Hauptdolomit depositional system in the central Alps: Coupling sea-level and climate changes. Palaeogeography, Palaeoclimatology, Palaeoecology 290: 138-150
BOSELLINI, A.; GIANOLLA, P. & STEFANI, M. (2003): Geology of the Dolomites. Episodes, Vol. 26(3): 181-185
CITA, M.B.; ABBATE, E.; ALDIIGHIERI, B.; BALINI, M.; CONTI, M.A.; FALORINI, P.; GERMANI, D.; GROPPELLI, G.; MANETTI, P. & PETTI, F.M. (ed) (2005): Catalogo delle formazioni. Unità tradizionali, Carta Geologica d'Italia 1:50.000, Quaderni serie III, Volume 7, Fascicolo VI: 318
LEPSIUS R. (1876) - Einteilung der alpinen Trias und ihr Verhaltnis zur Ausseralpinen. N. Jahrb. Min. Geol. Paleont.: 742- 744, Stuttgart.
NITTEL, P. (2006): Beiträge zur Stratigraphie und Mikropaläontologie der Mitteltrias der Innsbrucker Nordkette (Nördliche Kalkalpen, Austria). geo.Alp, Vol.3: 93-145
STEFANI, M.; FURIN, S. & GIANOLLA, P. (2010): The changing climate framework and depositional dynamics of Triassic carbonate platforms from the Dolomites. Palaeogeography, Palaeoclimatology, Palaeoecology 290: 43-57
VonGUEMBEL C.W. (1857): Untersuchungen in den bayerischen Alpen zwischen Isar und Salzach. Jahrb. K. K. Geol. Reichsanst., Jahrg. 7, H. I.: 146- 151, Wien.

30 August, 1965: The Allalin glacier Avalanche

The Allalin Glacier is a temperate glacier in the Vallese Alps (Switzerland). In the last centuries it became feared by its repeated advances and damming up of a melt water lake, which subsequently caused catastrophic outbursts floods.
At the end of the 19th century the glacier began to retreat, and during the first half of the 20th century the frontal part of the glacier tongue rested on the brink of a steep (27°) bedrock slope.

To prevent future inundations and to store the discharge of the glacier and use it to for a hydroelectric power plant, in 1964 the realization of a dam below the glacier fore field was decided. The construction works for the Mattmark dam began in 1965.

Some days before August 30, 1965 small ice blocks were observed falling down the slope, but this was not unusual.
On August 30. 1965, without warning, a major portion of the terminus of the glacier broke of, sliced down the rock slope and impacted on the huts of the construction site, 88 peoples working and living there were killed.

Fig.1. The Allalin Glacier before the ice avalanche, with marked glacier terminus part that caused the catastrophe, on the left corner the huts of the construction site (figure from HÖFLER & WITT 2010).

Subsequent investigations showed that the glacier avalanche occurred during a period of rapid advance of the glacier that started 2-3 weeks earlier, and pushed the front over a terrace in the bedrock. The glacier terminus slipped just on the margin of the steep slope, and became hold in place only by the connection to the glacier tongue. Finally the connection break off, the volume of the resulting ice avalanche was estimated to 1 million m3, and extraordinary and devastating event.

Similar seasonal changes in speed have also been observed in the years after the catastrophe, and it is now known that Allalin Glacier speeds up regularly every 1-3 years, usually during summer or late autumn. The acceleration is attributed to enhanced sliding, forced by the abundance of melt water, the different accumulation of ice masses by differences in the bedrock friction and the fragmentation of the glacier ice during the warm season.
In most cases however no large release of ice happens; evidently the speed-up event is necessary but not sufficient to cause breaking off. It is likely that geomorphologic factors, like the glacier bed topograpphy and a critical mass distribution inside the glacier, also contributed to the Mattmark catastrophe.

After the catastrophe a monitoring project of the Allalin Glacier was initialized. In 1999 the glacier configuration was similar to 1965, and for security reasons the hazard zone was closed during summer. An ice volume of 160.000 cubcic meters did in fact fell of, but did not cause any damage.

Despite the successful predictions in case of the Allalin Glacier, the mechanisms and relationships between glacier acceleration and break-off of large ice masses remain unclear, some steep glacier tongues switch between active and inactive phases, but other glacier tongues despite similar morphological conformations do not (for example the Giétroz Glacier in south-western Switzerland).

Fig. 2. Profile showing historical retreat of Allalin Glacier, Switzerland, and source of the 1965 glacier avalanche. The avalanche killed 88 construction workers at the Mattmark Dam construction site in the Saas valley (from EVANS & CLAGUE 1994).

Bibliography:

EVANS, S.G. & CLAGUE, J.J. (1994): Recent climatic change and catastrophic geomorphic processes in mountain environments. Geomorphology 10: 107-128
HÖFLER, H. & WITT, G. (2010): Katastrophen am Berg - Tragödien der Alpingeschichte. Bruckmann Verlag: 144

The Geo- Files:The unearthly cases in Geology: Ice from the Sky

Like in every other science also in geology there are presumed mysterious, unexplainable cases or artefacts - but most of these cases consists only of a collection of anecdotes or are simply retold without sceptic inquiry, but sometimes behind stories there are some interesting facts.

April 27. 2010 at 10.17 in the German village of Hettstadt (near the city of Würzburg): an ice block, 50 kilogram heavy, felt from the clear sky, breaking off branches of shrubs, damaging a pavement slab and excavating three craters, the largest 22 centimetre deep.
Such "megacryometeors" findings are reported from around the world, Jesús Martínez-Frías, researcher on the Centre for Astrobiology in Madrid, has documented 76 such impacts since 2002. One of the largest of these specimens is a presumed 400 kilogram block crashed in the Spanish city of Toledo in 2004.

Fig.1. (A) Megacryometeor in situ that fell in La Milana, Soria (27 January 2002). It landed near a startled farmer who was riding his tractor. More than 16 kg of ice was recovered by the environmental police of the Guardia Civil (Seprona). The size of the small impact crater generated by the megacryometeor was ca. 50 cm.
(B) One of the fragments of the megacryometeor that fell in San Feliz de Lena (Asturias) (26 January 2000) (artificial illumination to highlight its textural features), from MARTINEZ-FRIAS 2006.

The origin of the ice block remained a mystery, speculation about giant hailstones, defect airplane toilettes, ice meteorites and even terroristic attacks emerged.

The German Meteor however was analyzed by the meteorologist Frank Böttcher (Instituts für Wetter- und Klimakommunikation - IWK, a private company).
The chemical composition of the specimen of Hettstadt showed no differences to rain, the ice therefore was formed in the atmosphere, and is not of extraterrestrial origin. The lack of traces of human urine, disinfection solutions or other artificial chemical components also excludes the provenance of the water from an airplane toilette or an elaborated fraud.

The airspace of the village in the morning of the event was over flown by two airplanes in an elevation of 10.730m and 11.890m, calculating the time for the block to reach the surface, and considering the direction of the impact (deduced from the form of the impact crater and the broken branches) Böttcher showed that it is possible that the ice came from the location of one of the airplanes.
It's not unusual that ice forms by condensing vapour on wings of airplanes, also it is possible that blocks large enough reach the surface. The origin of ice from the hull of planes will probably explain the majority of reported cases of ice - "meteors", maybe also a in part misleading name for a terrestrial phenomena.

Nevertheless it´s seems that not all cases can be explained by ice coming from airplanes, Martínez-Frías in his archive collected reports of ice felt from the sky in the first half of the 19th century, when planes didn't exist; also some recent cases of ice blocks do not correlate with planes passing by the site of discovery.
At least a part of the ice chunks must have a natural origin without planes interference , possibly like hailstones strong air currents hold them floating until the weight is to great and they crash onto earth.

Bibliography:

MARTINEZ-FRIAS. J. & HUERTAS, A.D. (2006): Megacryometeors: Distribution on Earth and Current Research. AMBIO: A Journal of the Human Environment 35(6): 314-316

Online Resources:

BOJANOWSKI, A. (23.08.2010): Einschlag bei Würzburg: Forscher löst Rätsel der fliegenden Eisbombe. (Accessed 27.08.2010)
MARTINEZ-FRIAS, J. (2000-2010): Megacryometeors - Extreme atmospheric events. (Accessed 27.08.2010)

August 27, 1883: Krakatoa - The day the world exploded

"Perhaps, however, the most important evidence of what was actually going on at Krakatoa during the crisis of the eruption is that derived from witnesses on board ships which sailed between Java and Sumatra while the great outburst was in progress, or those that were at the time in the immediate vicinity of either the eastern or western entrance of the Sunda Strait. From many more distant points, however, valuable confirmatory or supplementary evidence has been obtained, for which we are indebted to the captains or passengers of vessels passing through the eastern seas during that period. Only three European ships appear to have actually within the Sunda Strait during the heigth of the eruption on the night of the 26th August and the early morning of the 27th, and to have escaped destruction, so that those on board could tell the tale of what they witnessed. " (SYMONS 1888, pag.15)

Fig.1. Ship routes and -positions 27. Agust 1883 (Topographic Map from Wikipedia, Ship positions from SYMONS 1888).

When the Batavian steamship "Gouverneur-General Loudon", under the command of T.H. Lindeman, approached the harbour of Anyer at ca. 14.00 o'clock August 26. 1883, the first explosion was reported, with a white cloud rising above the volcano and the sea, which showed a strange behaviour: the sea level was rising and falling in an irregular pattern. The city of Anyer was soon covered by a white to dark described cloud, blocking the sun and causing darkness. At 14.45 the Loudon full of passengers started their voyage to the 65 kilometers distant Telukbetung in Sumatra. Commandant Lindeman tried to remain as much possible to the east of the exploding island, to avoid the ash and pumice rain:

"Monday, August 27th. Finding that at midnight on the evening of our arrival [Aug. 26, 7:30 p.m.] there was still no boat come off to us from the shore, and as the weather was now much calmer, I sent the first mate in the gig with a crew of six men to find out what was the reason of this.
About 1 a.m. he returned, and stated that it had been impossible to land on account of the heavy current and surf; also that the harbour pier-head stood partly under water. The Government steamer Berouw, which lay anchored near the pier-head, hailed the mate as he was returning on board, and the people on board her then stated to him that it was impossible to land anywhere, and that a boat which had put off from the shore had already been wrecked.
That by 6 p.m. on Sunday evening it had already begun to be stormy, and that the stormy weather had been accompanied by a current which swept round and round (apparently a sort of whirlpool). When the mate had come on board, we resolved to await daylight before taking any further steps; however, for the sake of security, we steamed several ships' lengths outwards, because the sound of a ship's bell which seemed to be approaching us made us suspect that the ship must be adrift, and wishing therefore to avoid a collision we re-anchored in nine fathoms with thirty fathoms shackle outside the hawsepipe.
We kept the ordinary sea-watch, and afterwards heard nothing more of the bell. When day broke, it appeared to us to be still a matter of danger to send a boat ashore; and we also discovered that a revenue cutter was foul of a sailing-vessel which lay in the roadstead, and that the Berouw was stranded. However, owing to the violent winds and currents, we did not dare to send a boat to her assistance.
About 7 a.m. we saw some very high seas, presumably an upheaval of the sea, approaching us up the roadstead. These seas poured themselves out upon the shore and flowed inland, so that we presumed that the inhabitants who dwelt near the shore must be drowned. The signal beacon was altogether carried away, and the Berouw then lay high upon the shore among the cocoanut trees. Also the revenue cutter lay aground, and some native boats which had been lying in the neighborhood at anchor were no more to be seen.

Since it was very dangerous to stay where we were, and since if we stayed we could render no assistance, we concluded to proceed to Anjer under steam, and there to give information of what had taken place, weighed anchor at 7:30 a.m., and following the direction of the bay steered thereupon southwards.
At 10 a.m. we were obliged to come to anchor in the bay in 15 fathoms [27,5m] of water because the ash rain kept continually growing thicker and thicker, and pumice-stone also began to be rained, of which some pieces were several inches thick.
The air grew steadily darker and darker, and at 10:30 a.m. we were in total darkness, just the same as on a very dark night. The wind was from the west-ward, and began to increase till it reached the force of a hurricane.
So we let down both anchors and kept the screw turning slowly at half speed in order to ride over the terribly high seas which kept suddenly striking us presumably in consequence of a "sea quake," and made us dread being buried under them. Awnings and curtains from forward right up the main-mast, three boat covers, and the uppermost awning of the quarter deck were blown away in a moment. Some objects on desk which had been lashed got loose and were carried overboard; the upper deck hatchways and those on the main deck were closed tightly, and the passengers for the most part were sent below.
Heavy storms.
The lightning struck the mainmast conductor six or seven times, but no damage. The rain of pumice-stones changed to a violent mud rain, and this mud rain was so heavy that in the space of ten minutes the mud lay half a foot deep. Kept steaming with the head of the ship as far as possible seawards for half an hour when the sea began to abate, and at noon the wind dropped away entirely. Then we stopped the engine. The darkness however remained as before, as did also the mud rain." (from VanSANDICK)

The ash rain and the Tsunami as experienced on the Loudon, dramatization from the BBC docu-drama, "Krakatoa: The Last Days.":





Captain Thomson of the Medea, anchoring 130 kilometers east of Batavia, later estimated the height of the cloud up to 27 kilometers, he also reports "electric signs" in the clouds and strong explosions shaking in short intervals the ship.
At Monday at 5 o'clock in the morning three ships were still on the sea in the narrowest part of the Sunda Strait, the Loudon, incapable to reach Telukbetung because of the rough sea, the Marie and the Charles Bal. All three ships were covered by hot ash and pumice.
Captain Lindeman decided to anchor in the Lampung bay, also the Danish merchant Marie stopped. The Irish merchant Charles Bal, under the commando of captain W.J. Watson, in a desperate attempt to find a way out of the dark cloud approached the island of Krakatoa up to 16 to 18 kilometers, the nearest position of all surviving testimonies.
At Sunday 13.30 he was approaching the island in the middle of the strait (Watson reported the time 1 hour to early, here the indications are corrected to match the general chronology):

"…we observed a strong movement at the peak of Krakatoa, clouds or something were being propelled from the nort-east point with great velocity.
At 14.30 we heard about us and around the island a strange noise, like a crackling fire or the heavy artillery firing every few seconds. At four o'clock there was still thundering and it become even stronger, and a gloom spread over the sky, and a hail of pumice crackled on us, many of the pieces were of notable size and quite hot. We had to cover the lights, to secure the glass, and had to protect our feet's and heads with boots and coats.
..we remained on that course until we sighted a lighthouse at 18 o'clock, which we thought was Fourth Point, then we turned into the wind, SW, because we could hardly see anything and did not know what was going on in the strait.
The night was terrible, sand and rocks fell on us and made us blind. About us and around us there was absolute darkness, broken only by the incessant flashing of lightning, and then the constant noise of the explosion of the Krakatoa - our situation was really bad.
By 22 o'clock an island became visible. Fire tails seemed to descend up and down between it and the sky, and in the southwest we saw rise steadily white balls of fire.
The wind was strong, but hot, suffocating and sulphurous, it smelled like charred ash, and some of the stones that felt on us, were like iron slag. The plumbline coming from a depth of thirty fathoms [55m] was still warm.
From midnight to 3 o'clock in the night of the 27th the same impenetrable darkness persisted, while the noise of Krakatoa sounded less continuously, but more explosive, the sky was dark black in a second, and in the next bright light. The masts and frames flickered in a dead fire, and a strange pink-colored flame spout out of fluffy clouds, seeming to touch the mast.
At 5 o'clock we recognized the coast of Java, set sail and passed the lighthouse of Fourth Point. At 7 o'clock we winded up our signal flags, but received no answer.
At 7.30 we passed Anyer, our name still set and close enough to see the houses, but could see nothing moving, in fact across the entire Sunda Strait we saw nothing on the sea or on the land moving.
At 9.15 we passed Button Island, distant a quarter to half a mile, all around the sea like glass, and the weather looked much better, here no ash or slag was falling down, weak wind from SE.
At 10.15 o'clock we heard a terrible explosion in the direction of the Krakataoa, now more than 30 miles distant. We saw a wave impacting on Button Iceland and apparently sweeping across the southern part ...
... at 10.30 we were surrounded by a darkness that was almost to grasp, and then a deluge of mud, sand, and I do not know what began.
... We placed two men on the lookout, the mate and second mate on the flanks, and a man washed the dirt from the compass. We had seen two ships to the N and NW, before the sky darkened, so our situation was becoming even dangerous.
By noon it was so dark, that we had to grope on the deck, we could speak, but not see each other. This terrible condition and the rain of mud and debris continued until 12:30 o´clock. The thunder and lightning of the volcano was something awful.
At 13 o'clock we could see some of the yards above us, and the mud rain stopped, at 16 o'clock northwards and eastwards the horizon appeared, and we recognized West Island in direction O to N, just barely visible.
By midnight the sky remained gloomy and cloudy; occasionally some sand came down, the volcano rumbled in the distance, even though we were 75 miles distant from Krakatoa. Such darkness and such a situation only a few can ever imagine, and probably many would consider it unthinkable. The ship seemed cemented from the knob of the flag to the water line: spars, sails, blocks and ropes were terribly dirty, but Thank God no one was injured and the ship undamaged.
But imagine Anyer, Merak, and other small villages on the coast of Java!"

Bibliography:

SYMONS, G.J. (1888): The Eruption of Krakatoa, and subsequent phenomena. Report of the Krakatoa Committee of the Royal Society. Trübner & Co., London.
WINCHESTER, S. (2003): Krakatoa - Der Tag, an dem die Welt zerbrach. Albrecht Knaus Verlag: 367

Online Resources:

BBC World Witness (27.08.2010): Witness talks by Simon Winchester. (Accessed 27.08.2010)
LINDEMAN, J. (1883): Summary of Events. (Accessed 27.08.2010)
VanSANDICK: Krakatau/Krakatoa/Krakatou - 120e Verjaardag. (Accessed 27.08.2010)

Outburst flood from Glacier de Tete Rousse: A past and future threat

To protect the 3.000 inhabitants of the France village of Saint-Gervais–Le Fayet from a possible glacier outburst, the authorities have decided to drill into and install pumps on the Glacier de Tête-Rousse (Mont Blanc Massif), where a larger volume (65.000 cubic meters) of stagnant water is presumed. A supraglacial lake containing estimated 25.000 cubic meters water was discovered during this March, the authorities now fear that the water could be released in a sudden outburst when the surrounding icewalls collapse or the water excavates an outlet. In the course of this week the base camp at 3.200m a.s.l will be prepared, the drilling and installing of the pumps will presumably be concluded until October, before the onset of the winter.

Meanwhile the residents of the villages were warned of the possible danger and a evacuation plan is in elaboration.
The precautions are not entirely unfounded; in the night between July 11. and 12., 1892 the village of Saint-Gervais was severely damaged and 175 peoples killed by a 200.000 cubic meters outburst coming from the Tête-Rousse Glacier.
In the Alps, outburst floods from intraglacial cavities are not rare but generally lead to only small discharges and debris flows causing little or no damage. The outburst flood from Tête-Rousse was, however, one of the deadliest disasters ever caused by a glacier.

Before 1878, in a period with increased rate of ablation, a supraglacial lake formed in the centre of the glacier, this lake subsequently became covered by ice and snow.
The collapse of the glacier tongue in 1892 finally released the accumulated water, a large cavity 40m in diameter and 20m high containing estimated 20.000 cubic meters water at the glacier terminus remained as testimony. From this lower cavity, an 85m long intraglacial conduit led to the upper cavity (the former lake) with an additional volume of 80.000 cubic meters.

Fig. 1. The lower cavity at the terminus of the glacier, note epeople for scale. A part of the snout has been torn from the glacier. Photograph by H. PELLOUX, September 1892, figure from VINCENT et al. 2010.

Fig. 2. The upper cavity (former supraglacial lake) at the centre of the glacier. Photograph by M. KUSS, 13 August 1893, figure from VINCENT et al. 2010.

Fig. 3. Longitudinal section of the tongue, sketch from VALLOT and others (1892), figure from VINCENT et al. 2010.

After the catastrophe a monitoring program was initialized and in 1898-1899 a horizontal tunnel drilled to prevent water accumulation inside the glacier. In 1901, a 50m long and 40m deep crevasse became filled with water, so until 1904 a new tunnel was constructed, and 22.000 cubic meter water drained. This tunnel still exists and is supposed to prevent water accumulation close to the bedrock of the glacier.

Fig. 4. Map of surface and bedrock topography in 2007. The locations of the upper cavity and lower cavity (green dashed curve) and the excavated tunnels 81899 and 1904) are shown.

References:

VINCENT, C.; GARAMBOIS, S.; THIBERT, E; LEFEBVRE, E.; LeMEUR, E. & SIX, D. (2010): Origin of the outburst flood from Glacier de Tète Rousse in 1892 (Mont Blanc area, France). Journal of Glaciology, Vol. 56(198): 688 - 698

August 24, 79: The last day of Pompeii

"The last day of Pompeii", painted between 1830 and 1833 by K.P. Bruelow, State Russian Museum, Saint Petersburg. I posted about the taphonomy of the volcanic eruption of the Vesuvius here. There exists also an reconstruction of the eruption phase in form of a documentary by the Discovery Channel.