THE VOLCANIC ERUPTIONS IN THE STRAITS OF SUNDA.

Inangahua Times, Volume XI, Issue 1653, 15 January 1886, Page 2

THE VOLCANIC ERUPTIONS IN THE STRAITS OF SUNDA.

j ne toiiowuig paper was suomtttefi l»y Mr Daniel Ploos van Ainstel, Consul-general in Melbourne, for the Netherlands, at the meeting of the Royal Society of Victoria, held on December 10. The volcanic erution on the island of K-akutau in August 1883, induced the. Netherlands- Indian Government to commission Mr R. D. M. Verboek, of Batrtvia. to draw up a full and exhaustive report as to its causes and envois. The first portion of that report ' appeared in print in t lie course of last year, and an extract of that portion, 1 translated from the Dutch, was ?-ead at 1 the ordinary meeting of t lie Rcval i 8 uiety of Victoria on '.he 10th of July 1834. The second portion, which i completed the report has recently beeu I published, ac "ompaiiii'd l>y 25 coloured f plates and 43 lir^e and small maps, 1 and « Fiench translation of Mr E. D. '< M. Veibeok's Krakntn will shortly appear. 'I'h report will lie found a ' moat valuable contribution to J>he 1 literature of earthquakes and voll eanie eruptions, and as a standard 1 \v<»rk tvill ha juileH by th's .scientific world with mote than ordinary interest. The first part of Mr Vet Week's work, 1 which appeared last year, is divided into three chapters, the .first containing a history of Krakatau previous to the 1 eruption of 1883, the second reports i about the eruption of the 20th of May ' to the 2Q ! -h of August, 833, while the i third chapter deals with the terrific eruptions of 28tli, 28th Angus*, 18S3. The second and last report, only recently published, is divided into four chapters — viz., iv., v.. vi., vii. The foui'tii chapter treats of the causes which led to the eruption and eruptions in general. The fifth chapter deils with the phenomena in connection with the eruption of 1883. The sixth chapter describes the volcanic phenomena which have taken place at the time of the ernpMoii a*, other places within and outside of the Indian Archipelago, aud lastly the seventh chapter furnisnes an explanation of the maps and plates and a description of the voyage of the commissioners. Each chapter 'is subdivided into various parts so as to enable the reader to readily refer to any subject he d .-sires to bo informed upon, and although some parts of the work, as, for instance, the macrocospio and microscopic investigations into the nature of the Karkatapu lorma tions the various analyses, the description of the. geological strata of the islands and shores of the Straits of Sunda, of the underground of Krakatau, require n t!ioru«jh knowledge of geology to be fully understood. Yet, on the whole, Mr Verbeck's famous work of Krakatan will be read with unflagging interest by the educated reader. The island of Krakatau is situated at the junction of three fissures or crevice?, forming lines of weakness of the crust of the earth. The erup tions comu'enced on the 20th of May, 1883, and finally ceased on the 28th of August 1883. The most terrific of these eruptions took place on the 27tb of August 1383, when in the morning the weather became windy and sfloQtnv, with tlie barometer standing at 8023. The sun became gradually obscured, and it commenced to grow dark. The barometer rose and fell an inch at the rime, and before 10 o'clock in the forenoon an impenetrable darkness set in, relieved by flashes of forked lightning, and accompanied by a rumbling sound as that of distant thunder All of a sudden, ft terrific squall, accompanied by a heavy shower of rain and ashes, spread terror far i«nd wide The mysterious rattling, rumbling sound, as though of distant thunder ; the loud reports like the discharge of heavy artil'ery; a strong smell of sulphur pervading the air, and making it difficult to breathe; the fearful flasV ings of incessant lightning, and a wilder and morn awful scene was never witnessed by the eye of man. Amidst this scene of nature's wildest mood, a loud and deafening crashing sound, as though the death knell of <

the world had son tided, struck man dumb with fear and terror. The central part of the volcano— a mass of «boat 1094 cnbicyavls (one cubic kilometre) suddenly cave! in, and immense clouds of pnmice str hh and ashes rose to a dazzling height, and the roaring waters closing over, the steaming crater l»urst hissing on the red hot lava. The sea foaming and writhing under the falling misses of earth, rose suddenly to a height of n»)re than 100 ft — 30 meres— and submerging the sur ounding siiores, sent thousands of souls withont a warning to their last account The ships in the Sunda Straits, eovt red with ashes, were tossed about like cockleshells in tho surging ashy waves, and in the impenetrable darkness, the wind how. ling dismally through the rigging, the crew, dumb with fear and terror, had to grape their way with footsteps creak ing on the ni ss of ashes, that covered the deck l»y tons, and stuck like glue to the masts and rigging. On the following d- y, August 28th, the morning gradually broke, aivl the sun Woming slrwiy visible, revealed in all its terrors the scenes of destruction of the day before. The smionnding shores, covered with ash<« to a depth of a»»out 2in, appeared as though resting under a mantle of snow. Dead bodies, wrecked houses, nproo'ed trees were strewn over the land ; whilst corpses floating amidst vast masses of pnmice stone «*nd dead fishes collided with the shif * and boats, and told th« harrowirg t* '*• of the Krakitnu eruption. One or the maps which accom* panics the work shows the area of submerged -tnd, and another th» ntauner in vhich direction of the waves had been aflheted by the *ur--1 r uin i z islands. The effect of Vie ■ Rtakutau wa*e, which was in no way a tidal wave, being unconnected with any ebb or flv>d, was felt, at variont places allovr the wo Id, and from the rapidity with which it travelled, reaching Ad; n in 12 hours, thfc learned writers comes to tl c concl si n that the depth of lue Lidiau Ooea:> between Kmkatau and South Af.ica is 14,000 ft (4200 metre?), »>etwt*en Krakitai and K d iquez lo.OOOft (4530 metres), and between K ;ik;itan and South G-'or^ia 20,000 ft (6340 metres ) Coneeq lently, a very deep ocean bed exists to the nvest and southwest of Austral i», «oumHin ,'S of whicl lave neve i»-en tnk» n . 8 yet At this 3tage the writer expresses his regret tint no tide gauges exist at a greater nu nber of places aloig th>> s' tores of the Pac tic and Atlantio Oceans so as to be able to morn narrowly watch the movements of the S3a. With the C2;itral p.-»rt of the volcano the whole of the northern part of Krakatau f»-ll in, and is now covered by the sea :o a depth of 600 to 1000 EujHsh fo.it ,'2OO to 300 metres). T i» small islanr , PooUvuh Hoed, entirely disappeared, whilst a portion of the bottom of the sei siirronuding Kmkatan also fell in. Tlie, bottom of th * S'inda Strsit3 and the swron-idin j adores n idei^ont no change. In t • fourth chapt-T the writer calls attention to the geographical situation of tha volcanoes of the earth, being spread over the gto ia with some regularity in longer or shorter ranges, one behind the other, as, for instance, the volcanoes of South and Central America, of Alaska and the Aleutau Islands, of Kamschatk*, the Kuriles, and Japan, of the Philippines and North CMeb.t (M^nado) and lastly of the smaller Snnda Islands of Java and Sumatra. This peculiarity of position is in no way to be ascribed to mere chance. There mast be a cause, which forced the melted natter to appear by preference in certain directions, and it U selfevident that this cause is to be traced to the fissures r r crevices of the crustof the earth, fonni ig as it were a line of weakness. Capillary intrusion of sea- water to the volcanic foci, or water percolating or rushing through fissures or crevios into the sjbteranean cavaties, produces steem of a high temperture, and pressure is generated. Aristotle already assigned the origin of earthquakes priding volcanic «ruptions o B "eat i ; and although this hypo* thesis has :' eg teutly proved to Iw f correct, yet previous to the Krabatau orupti m nc ea th tremors, or s'locki had b^en ex )e«ienO'-d. Tae e*»-th, as supposed *»y the author, has partially cooled down, and whilst the crust of the earth, R*s '^en hardnej into a solid mass, and the kernel of the. earth where the heaviest matt^f»~Jjave accumulated is a solid mass, under tiid immense pressure there existing a riu..j or girdle of fluid melted mater must likely exists between the crust and the kernel of earth. It is further supposed that this matter passes up. | wards into some of the higher situated cavities, whi;h in-ide of the solid crust of the eirth, forms lakes of bj.ning lav i. Usually streams of lava, Wiwn the vo c^no is at work, fli-v from the orator, and n'no par idea of sand and ashes are ejected with immense force. The Erakataj eruption, however, was not accompanied by any streams of iavu, only pieces of punice st >ne, ashes, and hot mud were ejected, the steam evidently pressing f he matter upwards though the lava with -,'i eat f>rce. The earth shock? and tremors frit in Australia between the 26 h »nd 23th of August 18^3, point to a connection between the sunttri-anean cavities lying underneath Australia and the island of Rarakatau, a di!f'ro:ico of pressure in the one civity produciog a difference of pressure I'ie other. In concl ision, the author, as a result of his researches, believes that » portion of our globe is still in an incandescent molten state, and discount* nances the theory, which to some exter.t obtains at present, that the volcanic foci should be the result of chemical combinations. The author deals exhaustively with ejected matter which, according tolas statement, con* sisted to the extent r»f 95 per cent of

pimice stone mid »'h*s, and was ej eel wi'h a velocity exceeding that of pvoj ■.•ti!-s t" > n cannon. The t.nckness of th-> <>j "•!•(! milter in some places on t!i<> hh- I if K -)kot iv is estimated at nbo'it 200 ft 61 inetics), whilst the siz* of thr K-Mk-itao products range f i-o'n 1S 27 .-nbie yards (cubic metre) to th.. fi -ipjit particle of ash. The writer cals-i'nt s fro -n <lat* supplied to bun tint the total maw of the ejected m*"iteramvvit"t to 4 1 6 cubic mtleg (19 cnHic-kilo'ivtres). From reports reo-ived since fi-om commanders of vessels, misses of pumice stone were mot with ii Miy. ISSi, on the east coast, of Africa, whilst vast misses are now floating netween the Coroline and Mirshall Islands, and are likely ti reach the shores of South America, j near Panama, in the beginning of 1886. j Amongst the pj-ctel matter, w ; ''< attained a hei-.'bt of about 170.000 En/lish feet (50 kilometres), were found the socallod "Kiki^-i nnrble3)," smi.ll round bodies containing lime and clay. In the ».pgin-iing they were found lome on th«* Tini'v st.onp. but were afterwards net with imbedded in pieces of clay stone 1 Tn the first portion of Mr' VeiVek's report, the roundness of these bodies was attributed to the quick rotary motion at the time of the ejection. This explanation now falls to the gmnn 1, as thpse Wdies mnst.haveKeen round More they wpre ejected from the crater. The perfect roundness of these marbles or bullets is a most remarable fact, and unknown amongst the various concretions yet desoHb^d. It is «Iso difficult to exrtain howit isthat these bodies so rich in lime should be found in stones or pieces of rocks enirely free flora lime. Amongst theKrakatau products wetv also found masses which evideity did not form any constituent part of tha volcano itself, but were thrown up from the underground of Krakatan. Tli3 ejection of matter from the crater was accompanied by load reports which wereheard, us the accompanying map will show, over the immense area of 1 14 th part of the globe. No such distance was ever recorded before. Some of the reports were heard at Derch in New Guinea Duly Waters and Alice Springs of Central Australia, on t'je island of Eo-Wqn.es. and Ceylon. The most terrific exnlcsion, which took place at abont 10 o'clock in the forenoon t>f the 27th August, 1833, produced air waves of immense length of wave, travelling round the world in 35J toonrs. It is also stated that at that time an immense ash-clond rose from tlm crater to a height of ahout 170,000 ft (50 kilometres), travel l-in-i from th« 27th of August. 10 a','lo<?lc p.m., to 6 o'clock p.m. on the 9th of September, thus in 13£ days from Krakataa via Ti-inidvl, Fining's Island, and Strong's Island to Galle and Madras, a distance of 23.000 miles— from oth of S-ptembrr, 6 o'clock p.m., to the 22: id of Septenibov, 6 o'clock a.rn ; thus in 12J days th* ash cloud travelled right round the world. In regard to tue mignetm and meteorological phenomena, as nVrfservpd at Batavia, by Dr P. T. Van der Stok, director of" the Meteorological Observatory, the vibrations of the magnetic TieenMe as shown in map. fig, 8, were not the eflhc of the eruption itself, but solely the result cf the rain of allies at Batavia, these, ashes containing a magnetic constituent, the magnetic iron ore. These magnetic disturbances teased with the rain of a«hes. At that time the temperature fell considerably, which was caused, as the writer states, tiot by any evaporation of the moisture of the ashes, b:it by the ashes having greatly cooled down in the higher strata of the atmosphere. Electric discharges took place in the ash cloud and the lightning struck the lightlimise at Java's first point, and Falke Hock. No atmospheric electricity was experienced at Batavia. MrR. D. M. Verbeek h*s expressed bis hearty thanks to Mr Ellery (our wi-H known astronomer), to Mr Bussell of Sydney, to Mr Todd of Adelaide, and Dr Hector of Wellington, whose, interesting information in respect to tidal gauges, barograms, <>t<\, greatly assisted him in his va'nable work. The magnificent I>arograms from Sydney are specially mentioned, as they enabled him to fix the time of the heaviest explosion. — Argu*.