1883 eruption of Krakatoa

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1883 eruption of Krakatoa
De uitbarsting van de Krakatau, KITLV 5888.tiff
Photograph during the eruption in 1883
Volcano Krakatoa
Start date20 May 1883 [1]
End date21 October 1883 (1883-10-21) (?) [1]
Type Plinian eruption [2]
Location Krakatoa archipelago, Sunda Strait, Dutch East Indies (now Indonesia)
6°06′07″S105°25′23″E / 6.102°S 105.423°E / -6.102; 105.423
VEI 6 [1]
ImpactOver 70% of the island of Krakatoa destroyed and collapsed into a caldera; 20 million tons of sulphur released; volcanic winter causes five-year average world temperature drop of 1.2 °C (2.2 °F)[ citation needed ]
Deaths 36,417–120,000
Krakatoa map.svg
The change in geography after the eruption
Lithograph of the eruption c. 1888 Krakatoa eruption lithograph.jpg
Lithograph of the eruption c. 1888

The 1883 eruption of Krakatoa (Indonesian : Letusan Krakatau 1883) in the Sunda Strait occurred from 20 May until 21 October 1883, peaking in the late morning of 27 August when over 70% of the island of Krakatoa and its surrounding archipelago were destroyed as it collapsed into a caldera.

Contents

The eruption was one of the deadliest and most destructive volcanic events in recorded history. The explosion was heard 3,110 kilometres (1,930 mi) away in Perth, Western Australia, and Rodrigues near Mauritius, 4,800 kilometres (3,000 mi) away. [3] The acoustic pressure wave circled the globe more than three times. [4] : 63  At least 36,417 deaths are attributed to the eruption and the tsunamis it created.

Significant additional effects were felt worldwide in the days and weeks after the volcano's eruption. Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek's subsequent investigation into the eruption.

Eruption

Early phase

In the years before the 1883 eruption, seismic activity around the Krakatoa volcano was intense, with earthquakes felt as far away as North Australia, one of which, in 1880, damaged a lighthouse. [4] Strombolian activity began on 20 May 1883, and steam venting began to occur regularly from Perboewatan, the northernmost of the island's three cones. Eruptions of ash reached an estimated altitude of 6 km (20,000 ft), and explosions could be heard in Batavia (Jakarta) 160 km (100 mi) away, rattling windows and doors. [5] [4] Dust fell 300 miles away. An excursion party sent to the island on 26 May reported that the islands were covered with a fine white dust, with explosions coming from Perboewatan every 5 to 10 minutes. Although by this time the eruptions were calming down, some of the explosions were still very energetic, hurling pumice opposite the direction of the wind. A large crater about 3,000 feet (900 metres) in diameter formed, with a cavity from which issued plumes of steam. The eruptions soon quietened after the initial violence. [4]

Around 16 June, there were loud explosions and a thick black cloud covered the islands for five days. The eruptions started gaining strength again on 19 June. On 24 June, a prevailing east wind cleared the cloud, and two ash columns could be seen issuing from Krakatoa. It was also noticed that the summit cone of Perboewatan was gone, which an extensive report of a few years later attributes it to having been blown away. The seat of the eruption is believed to have been a new vent or vents that formed on that day, between Perboewatan and Danan. The violence of the ongoing eruptions caused tides in the vicinity to be unusually high, and ships at anchor had to be moored with chains. Earthquakes were felt at Anyer, Banten, and ships began to report large pumice masses to the west in the Indian Ocean. [5] [4] A third vent, and later many more, appeared. The eruptions continued throughout July, and their violence continued to increase until the explosions of 27 August. [4]

In early August, a Dutch topographical engineer, Captain H. J. G. Ferzenaar, investigated the Krakatoa islands. [5] He noted three major ash columns (the newer from Danan), which obscured the western part of the island, and steam plumes from at least eleven other vents, mostly between Danan and Rakata. When he landed, he noted an ash layer about 0.5 m (1 ft 8 in) thick and the destruction of all vegetation, leaving only tree stumps. He advised against any further landings. [5]

Climactic phase

By 25 August, the Krakatoa eruptions intensified. At about 1:00 pm on 26 August, the eruption entered its climactic phase. By 2:00 pm, a black ash cloud could be seen 27 km (17 mi) high. At this point, the eruption was almost continuous, and explosions could be heard every ten minutes. By 5:00 pm, the explosions were audible all over Java. Waves a few feet in height began battering the coasts of Java and Sumatra at 5:30 pm, and continued throughout the night, which may have been produced by steam explosions. [4] Ships within 20 km (12 mi) of the volcano reported heavy ash fall, with pieces of hot pumice up to 10 cm (4 in) in diameter landing on their decks. Between 7:00 pm and 8:00 pm, a small tsunami hit the shores of Java and Sumatra, 40 km (25 mi) away.

Explosions

On 27 August, four enormous explosions occurred, which marked the climax of the eruption. At 5:30 am, the first explosion was at Perboewatan, triggering a tsunami heading to Telok Betong, now known as Bandar Lampung. At 6:44 am, Krakatoa exploded again at Danan, with the resulting tsunami propagating eastward and westward. The third and largest explosion, at 10:02 am, was so powerful that it was heard 3,110 km (1,930 mi) away in Perth, Western Australia, and the Indian Ocean island of Rodrigues near Mauritius, 4,800 km (3,000 mi) away, where the blast was thought to have been cannon fire from a nearby ship. The third explosion has been reported as the loudest sound in history. [6] [7] [8] : 602  [4] : 79  The loudness of the blast heard 160 km (100 mi) from the volcano has been calculated to have been 180 dB. [9] Each explosion was accompanied by tsunamis estimated to have been over 30 metres (98 feet) high in places. A large area of the Sunda Strait and places on the Sumatran coast were affected by pyroclastic flows from the volcano. Verbeek and others believe that the final major Krakatoa eruption was a lateral blast, or pyroclastic surge. Material shot out of the volcano at 2,575 kilometres per hour (715 metres per second). [10] The energy released from the explosion has been estimated to be equal to about 200 megatonnes of TNT (840 petajoules ), [11] roughly four times as powerful as the Tsar Bomba, the most powerful thermonuclear weapon ever detonated. This makes it one of the most powerful explosions in recorded history. At 10:41 am, a landslide tore off half of Rakata volcano, along with the remainder of the island to the north of Rakata, causing the final explosion. [6]

Pressure wave

The sounds of the eruption of the Krakatoa volcano were estimated to be 310 dB SPL, and there are reports that it was heard some 1,300 miles away in the Bay of Bengal. Some islands in the western Indian Ocean, approximately 3,000 miles away, still heard it at a dB level near the same level as a gun blast. Due to the speed of sound, it is likely the people on these far away islands did not hear Krakatoa for nearly four hours after its eruption. The pressure wave generated by the colossal third explosion radiated out from Krakatoa at 1,086 km/h (675 mph). The eruption is estimated to have reached 180 dB, loud enough to be heard 5,000 kilometres (3,100 mi) away. [12] : 248  It was so powerful that it ruptured the eardrums of sailors on RMS Norham Castle of the Castle Line which was hove to off Sumatra, [12] : 231, 234  and caused a spike of more than 8.5 kilopascals (2.5 inHg) in the pressure gauge attached to a gasometer in the Batavia (correspondent to modern day Jakarta) gasworks 160 km (100 miles) away, sending it off the scale. At Batavia, the air waves burst windows and cracked walls. [4] : 69  [12] : 218  [note 1]

The pressure wave was recorded on barographs worldwide. Several barographs recorded the wave seven times over five days: four times with the wave travelling away from the volcano to its antipodal point and three times travelling back to the volcano. [4] : 63  Hence, the wave rounded the globe three and a half times.

Tsunamis
Coral block thrown onto the shore of Java by the tsunami COLLECTIE TROPENMUSEUM Groot brok koraal uit zee dat bij Anjer op land is geworpen na de uitbarsting van de Krakatau in 1883. TMnr 60005541.jpg
Coral block thrown onto the shore of Java by the tsunami

Massive tsunamis struck the coastlines of the Sunda Strait, entirely submerging some islands. Some 80 km (50 mi) away, the low-lying Thousand Islands were submerged under 2 meters (6.6 feet) of seawater, forcing people to climb trees. [13] The tsunamis produced by the third explosion were the largest, although the first two explosions did produce smaller tsunamis. [14] The town of Merak was destroyed by a tsunami that was 46 metres high. [note 2] The waves reached heights of up to 24 metres (79 feet) along the south coast of Sumatra and up to 42 metres (138 feet) along the west coast of Java. [15] The tsunamis washed the land clean of vegetation and destroyed human settlements. [13] The Loudon, which at the time was anchored near the village of Telok Betong, survived the waves. Passengers produced this eyewitness account: [13]

"Suddenly we saw a gigantic wave of prodigious height advancing toward the seashore with considerable speed. Immediately, the crew . . .managed to set sail in face of the imminent danger; the ship had just enough time to meet with the wave from the front. The ship met the wave head on and the Loudon was lifted up with a dizzying rapidity and made a formidable leap... The ship rode at a high angle over the crest of the wave and down the other side. The wave continued on its journey toward land, and the benumbed crew watched as the sea in a single sweeping motion consumed the town. There, where an instant before had lain the town of Telok Betong, nothing remained but the open sea."

A farm worker who was near Merak on Monday morning reports:

" . . .all of a sudden there came a great noise. We . . .saw a great black thing, a long way off, coming towards us. It was very high and very strong, and we soon saw that it was water. Trees and houses were washed away . . .The people began to . . . run for their lives. Not far off was some steep sloping ground. We all ran towards it and tried to climb up out of the way of the water. The wave was too quick for most of them, and many were drowned almost at my side. . . . There was a general rush to climb up in one particular place. This caused a great block, and many of them got wedged together and could not move. Then they struggled and fought, screaming and crying out all the time. Those below tried to make those above them move on again by biting their heels. A great struggle took place for a few moments, but . . . one after another, they were washed down and carried far away by the rushing waters. You can see the marks on the hill side where the fight for life took place. Some . . . dragged others down with them. They would not let go their hold, nor could those above them release themselves from this death-grip." [16]

Away from the coasts of the Sunda Strait, the waves reached a height of 4 metres on Southern Sumatra. One person was killed in Sri Lanka. [14] Ships as far away as South Africa rocked as tsunamis hit them, and the victims' bodies were found floating in the ocean for months after the event.[ dubious – discuss ] The tsunamis which accompanied the eruption were believed to have been caused by gigantic pyroclastic flows entering the sea; each of the four great explosions was accompanied by large pyroclastic flows resulting from the gravitational collapse of the eruption columns.[ citation needed ] This caused several cubic kilometres of material to enter the sea, displacing an equal volume of seawater. [note 2]

Smaller waves were recorded on tidal gauges as far away as the English Channel. [17] These occurred too soon to be remnants of the initial tsunamis, which owing to a wavelength of less than 7 km, failed to cause significant damage at large distance, [18] and may have been caused by concussive air waves from the eruption. These air waves circled the globe several times and were still detectable on barographs five days later. [19]

Pyroclastic flows and tephra
Rhyodacite pumice from the late August 1883 eruption of Krakatoa. This rock floated across the Indian Ocean for almost a year before it washed ashore at Takwa Beach, Kenya, East Africa. Rhyodacite pumice (late August 1883 eruption of Krakatoa Volcano, Indonesia; collected at Takwa Beach, coastal Kenya, eastern Africa) 1.jpg
Rhyodacite pumice from the late August 1883 eruption of Krakatoa. This rock floated across the Indian Ocean for almost a year before it washed ashore at Takwa Beach, Kenya, East Africa.

About 10% of the eruption fatalities were from hot pyroclastic flows and falling tephra. The pyroclastic flows and surges produced by the third explosion moved faster than 100 km/h (62 mph) and travelled over the sea up to 80 km (50 mi) from the source, affecting an area constrained to a minimum of 4,000 km2 (1,500 sq mi). Pyroclastic deposits thought to be from the flows have been found on Southeast Sumatra, and northwest of the volcano on the islands of Sebesi, Sebuku and Lagoendi, while on Southwest Sumatra the flows burnt victims. [20] They travelled 40 km (25 mi) across the Sunda Strait. Once they hit Southern Sumatra, they incinerated entire villages and burned all vegetation. 2,000 of the corpses in Southern Sumatra appear to have been scorched to death, presumably by the pyroclastic flows. The Loudon and the W.H. Besse, at ~65 km north-northeast and ~80 km east-northeast of Krakatau respectively, were hit by strong winds and tephra. They were farther away than the scorched victims of the hot flows in Sumatra, so the ships and crew survived. [13] The flows had moved across the water on a cushion of superheated steam. There are also indications of submarine pyroclastic flows reaching 15 km (9.3 mi) from the volcano. [21]

An eyewitness enveloped by the outermost edges of the pyroclastic flow described her experience:

"Suddenly, it became pitch dark. The last thing I saw was the ash being pushed up through the cracks in the floorboards, like a fountain. I turned to my husband and heard him say in dispair ' Where is the knife?' . . . I will cut all our wrists and then we shall be released from our suffering sooner.' The knife could not be found. I felt a heavy pressure, throwing me to the ground. Then it seemed as if all the air was being sucked away and I could not breathe. . . . I felt people rolling over me . . . No sound came from my husband or children . . . I remember thinking, I want to . . . go outside . . . . but I could not straighten my back . . . I tottered, doubled up, to the door . . . I forced myself through the opening . . . I tripped and fell. I realized the ash was hot and I tried to protect my face with my hands. The hot bite of the pumice pricked like needles . . . Without thinking, I walked hopefully forward. Had I been in my right mind, I would have understood what a dangerous thing it was to . . . plunge into the hellish darkness . . . I ran up against . . . branches and did not even think of avoiding them. I entangled myself more and more . . . My hair got caught up . . . I noticed for the first time that [my] skin was hanging off everywhere, thick and moist from the ash stuck to it. Thinking it must be dirty, I wanted to pull bits of skin off, but that was still more painful . . . I did not know I had been burnt." — Mrs. Beyerinck (of Ketimbang) [16]

An estimated 20 cubic kilometres of tephra was deposited. [13] Ash was propelled to an estimated height of 80 km (50 mi). It is estimated that as much as 18–21 km3 (4.3–5.0 cu mi) of ignimbrite were deposited over 1,100,000 km2 (420,000 sq mi). Around noon on 27 August 1883, a rain of hot ash fell around Ketimbang (now Katibung in Lampung Province) in Sumatra, known as 'The Burning Ashes of Ketimbang', killing approximately 1,000 people in Sumatra. [12]

Aftermath

The combination of pyroclastic flows, volcanic ash, and tsunamis associated with the Krakatoa eruptions had disastrous regional consequences. Some land in Banten, approximately 80 km south, was never repopulated; it reverted to jungle and is now the Ujung Kulon National Park. Ash fell 2,500 km away. Huge fields of floating pumice were reported for months after the event. [13] There are numerous reports of groups of human skeletons floating across the Indian Ocean on rafts of volcanic pumice and washing up on the east coast of Africa up to a year after the eruption. [12] : 297–298 

An observation made two weeks after the eruption describes the state of the affected areas, where the village of Tjaringin once was.

"Thousands of corpses of human beings and also carcasses of animals still await burial, and make their presence apparent by the indescribable stench. They lie in knots and entangled masses impossible to unravel, and often jammed along with coconut stems among all that had served these thousands as dwellings, furniture, farming implements, and adornments for houses and compounds." -- From Zeilinga de Boer and Sanders, 2002 [13]

Death toll

The official reported death toll was 36,417. [22] There were no survivors from the 3,000 people on the island of Sebesi. [12] : 297–298 

Official death toll [22]
LocationDeaths
Banten 21,565
Lampung 12,466
Batavia 2,350
Bengkulu 34
West Java 2
Total36,417

Geographic effects

Evolution of the islands around Krakatoa Krakatoa evolution map-en.gif
Evolution of the islands around Krakatoa

In the aftermath of the eruption, it was found that Krakatoa had almost entirely disappeared, except for the southern third. Much of the Rakata cone had been sheared away, leaving behind a 250-metre (820 ft) cliff. Of the northern two-thirds of the island, only a rocky islet named Bootsmansrots ('Bosun's Rock'), a fragment of Danan, was left; Poolsche Hoed had disappeared.

The huge amount of material the volcano deposited drastically altered the ocean floor. The huge amount of ignimbrite deposits largely filled the 30–40 m (98–131 ft) deep basin around the mountain. The land masses of Verlaten and Lang islands were increased, as was the western part of the remnant of Rakata. Much of this gained material quickly eroded, but volcanic ash remains a significant part of the geological composition of these islands. The basin was 100 m (330 ft) deep before the eruption, and 200–300 m (660–980 ft) after. [23]

Two nearby sandbanks (called Steers and Calmeyer after the two naval officers who investigated them) were built up into islands by ashfall, but the sea later washed them away. Seawater on hot volcanic deposits on Steers and Calmeyer had caused steam to rise, which some mistook for a continued eruption.

Global climate

The eruption caused a volcanic winter. [24] In the year following the eruption, average Northern Hemisphere summer temperatures fell by 0.4 °C (0.72 °F). [25] The record rainfall that hit Southern California during the water year from July 1883 to June 1884 – Los Angeles received 970 millimetres (38.18 in) and San Diego 660 millimetres (25.97 in) [26] – has been attributed to the Krakatoa eruption. [27] There was no El Niño during that period as is usual when heavy rain occurs in Southern California, [28] but many scientists doubt that there was a causal relationship. [29] [ failed verification ]

The eruption injected a tremendous amount of sulphur dioxide (SO2) gas high into the stratosphere, which was subsequently transported by high-level winds all over the planet. This led to a global increase in sulphuric acid (H2SO4) concentration in high-level cirrus clouds. The resulting increase in cloud reflectivity (or albedo) reflected more incoming light from the sun than usual and cooled the entire planet until the sulphur fell to the ground as acid precipitation. [30]

Global optical effects

1888 paintings, showcasing the optical effects of the eruption on the sky over time Houghton 71-1250 - Krakatoa, twilight and afterglow.jpg
1888 paintings, showcasing the optical effects of the eruption on the sky over time

The 1883 Krakatoa eruption darkened the sky worldwide for years afterwards and produced spectacular sunsets worldwide for many months. British artist William Ascroft made thousands of colour sketches of the red sunsets halfway around the world from Krakatoa in the years after the eruption. The ash caused "such vivid red sunsets that fire engines were called out in New York, Poughkeepsie, and New Haven to quench the apparent conflagration". [31] This eruption also produced a Bishop's Ring around the sun by day, and a volcanic purple light at twilight. In 2004, an astronomer proposed the idea that the red sky shown in Edvard Munch's 1893 painting The Scream is an accurate depiction of the sky over Norway after the eruption. [32]

Weather watchers of the time tracked and mapped the effects on the sky. They labelled the phenomenon the "equatorial smoke stream". [33] This was the first identification of what is known today as the jet stream. [34] For several years following the eruption, it was reported that the moon appeared to be blue and sometimes green. This was because some ash clouds were filled with particles about 1  μm wide – the right size to strongly scatter red light while allowing other colours to pass. White moonbeams shining through the clouds emerged blue and sometimes green. People also saw lavender suns and, for the first time, recorded noctilucent clouds. [31]

Later activity

Although the violent phase of the 1883 eruption was over by the late afternoon of 27 August, after light returned by 29 August, reports continued for months that Krakatoa was still in eruption. Verbeek's committee's earliest duties were to determine if this was true and verify reports of other volcanoes erupting on Java and Sumatra. In general, these were found to be false. Small eruptions, mostly of mud, continued into October 1883. Verbeek discounted any claims of Krakatoa still erupting after mid-October due to steaming of hot material, landslides due to heavy monsoon rains that season, and "hallucinations due to electrical activity" seen from a distance. [35]

No signs of further activity were seen until 1913 when an eruption was reported. An investigation could find no evidence the volcano was awakening. It was determined that what had been mistaken for renewed activity had been a major landslide (possibly the one which formed the second arc to Rakata's cliff).

Examinations after 1930 of bathymetric charts made in 1919 show evidence of a bulge indicative of magma near the surface at the site that became Anak Krakatau.

Possible causes

The fate of northern Krakatoa has been the subject of some dispute among geologists. It was initially proposed that the island had been blown apart by the force of the eruption. Most of the material deposited by the volcano is magmatic in origin, and the caldera formed by the eruption is not extensively filled with deposits from the 1883 eruption. This indicates that the island subsided into an empty magma chamber at the end of the eruption sequence rather than having been destroyed during the eruptions.

Based on the findings of contemporary investigators, the established hypotheses assume that part of the island subsided before the first explosions on the morning of 27 August. This forced the volcano's vents to be below sea level, causing:

Geological evidence does not support the assumption that only subsidence before the explosion was the cause. For instance, the pumice and ignimbrite deposits are not of a kind consistent with a magma-seawater interaction. These findings have led to other hypotheses:

Numerical model of hydrovolcanic explosion of Krakatoa and Tsunami generation

A numerical model for a Krakatoa hydrovolcanic explosion and the resulting tsunami was described by Mader & Gittings, in 2006. [36] A high wall of water is formed that is initially higher than 100 metres driven by the shocked water, basalt, and air.

The Scream. Edvard Munch, 1893, The Scream, oil, tempera and pastel on cardboard, 91 x 73 cm, National Gallery of Norway.jpg
The Scream.

See also

Notes

  1. ↑ A spike of more than 21⁄2 inches of mercury (ca 85 hPa) is equal to approximately 180  dBSPL; to compare this impact, the human threshold for pain is 134  decibels (dBSPL); and short-term hearing effect damage can occur at 120 dBSPL; [12] : 219 
  2. 1 2 A documentary film showed tests made by a research team at the University of Kiel, Germany, of pyroclastic flows moving over the water. See Freundt, Armin (2002). "Entrance of hot pyroclastic flows into the sea: experimental observations". Bulletin of Volcanology. 65 (2–3): 144–164. Bibcode:2002BVol...65..144F. doi:10.1007/s00445-002-0250-1. S2CID   73620085 . Retrieved 10 April 2012. The tests revealed that hot ash travelled over the water on a cloud of superheated steam, continuing to be a pyroclastic flow after crossing water; the heavy matter precipitated out of the flow shortly after initial contact with the water, creating a tsunami due to the precipitate mass.

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<span class="mw-page-title-main">Sebesi</span> Island in the Sunda Strait

Sebesi is an Indonesian island in the Sunda Strait, between Java and Sumatra, and part of the province of Lampung. It rises to a height of 844 metres (2,769 ft) and lies about 12 kilometres (7.5 mi) north of the Krakatoa Archipelago; it is the closest large island to Krakatoa, about the same area and height as the remnant of Rakata. Like Krakatoa, it too is volcanic, although no dated eruptions are known. Unlike the Krakatoa Archipelago, Sebesi has permanent streams and is inhabited. Habitation is concentrated most heavily on the northern and eastern coasts of the island.

<span class="mw-page-title-main">Types of volcanic eruptions</span>

Several types of volcanic eruptions—during which material is expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series.

<span class="mw-page-title-main">Kolumbo</span> Active submarine volcano in the Aegean Sea near Santorini

Kolumbo is an active submarine volcano in the Aegean Sea in Greece, about 8 km northeast of Cape Kolumbo, Santorini island. The largest of a line of about twenty submarine volcanic cones extending to the northeast from Santorini, it is about 3 km in diameter with a crater 1.5 km across. It was first noticed by humans when it breached the sea surface in 1649-50. The Smithsonian Institution's Global Volcanism Program treats it as part of the Santorini volcano, though at least one source maintains that it is a separate magmatic system.

<span class="mw-page-title-main">Taupō Volcano</span> Supervolcano in New Zealand

Lake Taupō, in the centre of New Zealand's North Island, fills the caldera of the Taupō Volcano, a large rhyolitic supervolcano. This huge volcano has produced two of the world's most powerful eruptions in geologically recent times.

<span class="mw-page-title-main">1815 eruption of Mount Tambora</span> Catastrophic volcanic eruption in Indonesia in 1815

Mount Tambora is a volcano on the island of Sumbawa in present-day Indonesia, then part of the Dutch East Indies, and its 1815 eruption was the most powerful volcanic eruption in recorded human history. This volcanic explosivity index (VEI) 7 eruption ejected 37–45 km3 of dense-rock equivalent (DRE) material into the atmosphere, and was the most recent confirmed VEI-7 eruption.

<span class="mw-page-title-main">Krakatoa archipelago</span> Archipelago in the Sunda Strait, Indonesia

The Krakatoa Archipelago is a small uninhabited archipelago of volcanic islands formed by the Krakatoa stratovolcano located in the Sunda Strait, nestled between the much larger islands of Java and Sumatra. As of 2018, the archipelago consists of four main islands: Verlaten, Lang, Rakata, and the currently volcanically active Anak Krakatoa. Together, the islands are a part of the Indonesian island arc system, created by the northeastward subduction of the Indo-Australian Plate. As part of a dynamic volcanic system, the islands have been continuously reshaped throughout recorded history, most notably in the 1883 eruption of Krakatoa.

<span class="mw-page-title-main">Volcanic tsunami</span> Natural hazard

A volcanic tsunami, also called a volcanogenic tsunami, is a tsunami produced by volcanic phenomena. About 20–25% of all fatalities at volcanoes during the past 250 years have been caused by volcanic tsunamis. The most devastating volcanic tsunami in recorded history was that produced by the 1883 eruption of Krakatoa. The waves reached heights of 40 m (130 ft) and killed 36,000 people.

References

  1. 1 2 3 "Krakatau". Global Volcanism Program . Smithsonian Institution . Retrieved 3 May 2021.
  2. ↑ Self, Stephen (1992). "Krakatau revisited: The course of events and interpretation of the 1883 eruption". GeoJournal. 28 (2). Springer Science+Business Media: 109. Bibcode:1992GeoJo..28..109S. doi:10.1007/BF00177223. S2CID   189890473 . Retrieved 20 May 2022.
  3. ↑ Chisholm, Hugh, ed. (1911). "Krakatoa"  . Encyclopædia Britannica . Vol. 15 (11th ed.). Cambridge University Press. p. 923.
  4. 1 2 3 4 5 6 7 8 9 10 Symons, G.J. (ed) The Eruption of Krakatoa and Subsequent Phenomena (Report of the Krakatoa Committee of the Royal Society). London, 1888. 1888 – via Internet Archive.
  5. 1 2 3 4 Thornton, Ian W. B. (1997). Krakatau: The Destruction and Reassembly of an Island Ecosystem. Harvard University Press. pp. 9–11. ISBN   978-0-674-50572-8.
  6. 1 2 Monique R. Morgan (January 2013). "The Eruption of Krakatoa (also known as Krakatau) in 1883". 'BRANCH': Britain, Representation and Nineteenth-Century History. Retrieved 5 February 2019.
  7. ↑ "How Krakatoa made the biggest bang"; The Independent , 3 May 2006
  8. ↑ Woulff, Gordon; McGetchin, Thomas R (December 1958). "Acoustic Noise from Volcanoes: Theory and Experiment". Geophysical Journal International. 1 (4). Oxford University Press: 601–616. Bibcode:1958GeoJ....1..601W. doi: 10.1111/j.1365-246X.1958.tb05346.x .
  9. ↑ Oliveira, Justin M.; Vedo, Sabrina; Campbell, Michael D.; Atkinson, Joseph P. (2010). "KSC VAB Aeroacoustic Hazard Assessment" (PDF). KSC Engineering, NASA. p. 43. Retrieved 15 November 2016.
  10. ↑ Filmer, Joshua (8 October 2014). "The Biggest Shockwave Ever Created by Earth".
  11. ↑ "The eruption of Krakatoa, August 27, 1883". Commonwealth of Australia 2012, Bureau of Meteorology. Archived from the original on 18 March 2016. Retrieved 5 April 2012.
  12. 1 2 3 4 5 6 7 Winchester, Simon (2003). Krakatoa: The Day the World Exploded, August 27, 1883. Penguin/Viking. ISBN   978-0-670-91430-2.
  13. 1 2 3 4 5 6 7 "How Volcanoes Work – Krakatau, Indonesia 1883". Archived from the original on 13 August 2008.
  14. 1 2 "Tsunami Event Information". National Geophysical Data Center.
  15. ↑ Bryant, Edward, Tsunami: The Underrated Hazard, Springer: New York, 2014, ISBN   978-3-319-06132-0, pp. 162–163.
  16. 1 2 Scarth, Alwyn (1999). Vulcan's Fury: Man Against the Volcano. p. 143.
  17. ↑ Press, Frank (November 1956). "Volcanoes, ice, and destructive waves" (PDF). Engineering and Science. 20 (2): 26–30. ISSN   0013-7812 . Retrieved 5 April 2007. Fortunately, the tide gauges of 1883 were sufficiently well designed to provide fairly good records of the Krakatoa waves. Thus we have instrumental data for the Krakatoa sea waves from such widely separated places as Honolulu, San Francisco, Colon, South Georgia and English Channel ports.
  18. ↑ "Numerical Modeling for the Krakatoa Hydrovolcanic Explosion and Tsunami".
  19. ↑ Pararas-Carayannis, George (2003). "Near and far-field effects of tsunamis generated by the paroxysmal eruptions, explosions, caldera collapses and massive slope failures of the Krakatau volcano in Indonesia on August 26–27, 1883" (PDF). Science of Tsunami Hazards. Vol. 21, no. 4. The Tsunami Society. pp. 191–201. ISSN   8755-6839 . Retrieved 29 December 2007.
  20. ↑ Carey1 Sigurdsson2 Mandeville3 Bronto4, S.1 H.2 C.3 S.4 (1996). "Pyroclastic flows and surges over water: an example from the 1883 Krakatau eruption". Bulletin of Volcanology. 57 (7): 493–511. Bibcode:1996BVol...57..493C. doi:10.1007/BF00304435.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  21. ↑ Mandeville, C.W.; Carey, S; Sigurdsson, H. & King, J. (1994). "Paleomagnetic evidence for high-temperature emplacement of the 1883 subaqueous pyroclastic flows from Krakatau Volcano, Indonesia". Journal of Geophysical Research: Solid Earth. 99 (B5): 9487–9504. Bibcode:1994JGR....99.9487M. doi:10.1029/94JB00239.
  22. 1 2 "How Volcanoes Work – Krakatau, Indonesia 1883". Department of Geological Sciences, San Diego State University. Archived from the original on 13 August 2008. Retrieved 28 January 2017.
  23. ↑ Mader, Charles. (2006). Numerical Modeling for the Krakatoa Hydrovolcanic Explosion and Tsunami. Science of Tsunami Hazards. 24. 174.
  24. ↑ "With a Bang: Not a Whimper" (PDF). University of Minnesota. Archived from the original (PDF) on 22 June 2010.
  25. ↑ Bradley, Raymond S. (June 1988). "The explosive volcanic eruption signal in northern hemisphere continental temperature records" (PDF). Climatic Change. 12 (3): 221–243. Bibcode:1988ClCh...12..221B. doi:10.1007/bf00139431. ISSN   0165-0009. S2CID   153757349 – via Springer.
  26. ↑ "Los Angeles and San Diego rainfall" (PDF). Archived from the original (PDF) on 13 July 2023. Retrieved 16 February 2014.
  27. ↑ Kuhn, Gerald G. and Shepard, Francis Parker; Sea Cliffs, Beaches, and Coastal Valleys of San Diego County: Some Amazing Histories and Some Horrifying Implications; p. 32. ISBN   9780520051188
  28. ↑ Kane, R.P.; Kane (1 August 1997). "Relationship of El Niño–Southern Oscillation and Pacific Sea Surface Temperature with Rainfall in Various Regions of the Globe". Monthly Weather Review. 125 (8): 1792–1800. Bibcode:1997MWRv..125.1792K. doi: 10.1175/1520-0493(1997)125<1792:roenos>2.0.co;2 .
  29. ↑ Mass, Clifford F.; Portman, David A.; Mass, Clifford F.; Portman, David A. (1 June 1989). "Major Volcanic Eruptions and Climate: A Critical Evaluation" (PDF). Journal of Climate. 2 (6): 566–593. Bibcode:1989JCli....2..566M. doi: 10.1175/1520-0442(1989)002<0566:mveaca>2.0.co;2 . JSTOR   26194042.
  30. ↑ "USGS: Volcano Hazards Program". United States Geological Survey. Archived from the original on 19 July 2023. Retrieved 14 October 2019.
  31. 1 2 "Blue Moon". NASA Science. Archived from the original on 6 April 2023. Retrieved 26 August 2013.
  32. ↑
  33. ↑ Bishop, S.E. (29 January 1885). "Krakatoa". Nature . 31 (796): 288–289. Bibcode:1885Natur..31..288B. doi:10.1038/031288b0.
  34. ↑ Winchester, Simon (15 April 2010). "A Tale of Two Volcanos". The New York Times. Retrieved 15 November 2010.
  35. ↑ Self, Stephen; Rampino, Michael R. (1981). "The 1883 eruption of Krakatau". Nature. 294 (5843): 699–704. Bibcode:1981Natur.294..699S. doi:10.1038/294699a0. ISSN   1476-4687. S2CID   4340524.
  36. ↑ Mader, Charles L.; Gittings, Michael L. (2006). "Numerical model for the Krakatoa hydrovolcanic explosion and tsunami". Science of Tsunami Hazards. 24 (3): 174–182.
  37. ↑ Olson, Donald W.; Russell L. Doescher; Marilynn S. Olson (May 2005). "The Blood-Red Sky of the Scream". APS News. 13 (5). American Physical Society. Archived from the original on 3 December 2007. Retrieved 22 December 2007.

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