Krakatau (grootste uitbarsting in moderne tijd), ook weer aktief

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Scientist: Massive eruption at Krakatau hundreds of years away
Mount Anak Krakatau located in Sunda Straits between Indonesia's Sumatra and Java islands needs hundreds of year to make massive eruptions, an expert said here on Monday.

Head of Geologic Agency at the Ministry for Energy and Mineral Resources R. Sukhyar told a parliamentary hearing that the 315 meter-volcano has been erupting in small scale.

"Magma inside the volcano is still watery. Frequent eruption is one characteristic of a growing volcano. After its body grows ( into a sizable measure), it will erupt and ruin its own body," said Sukhyar.

He also said that the eruption center keeps moving but still in the volcano body.

"For now, we don't have to worry. This is good news as energy of the volcano released little by little. This will prevent massive eruption in near term. It needs hundreds of year to materialize a massive eruption," he said.

He said that eruption materials have only been splashed to 700 meters into the sky.

"Usually the volcano erupts once in a year with duration of several months. The eruption is always not big with danger zone radius of 2 kilometers," said Sukhyar.

In fact, he said, the small eruption is a very interesting tourism object as long as tourists do not enter the danger zone.

"It is very beautiful and spectacular like firecracker. It is a very good tourism object in Banten and Lampung provinces," he said, referring to the two provinces sharing border in the straits.

Following eruptions of Mount Anak Krakatau on Jan. 11, 2011, Indonesia forced an evacuation of tens of thousands of people.

The last massive eruption of Krakatau was recorded on Aug. 27, 1883. The volcano erupted more than 18 cubic km of ash to a height of 80 km, and produced a tsunami as high as 30 meters along the west coast of Banten province and south coast of Lampung province.

The tsunami hit 295 villages and killed over 36,000 people.

Following the eruption, the mount collapsed and Mount Anak Krakatau was born

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Krakatau alert status higher - 2km Danger Zone
VIVAnews - Mount Anak Krakatau has seen quakes a thousand times. Its status has been elevated to "siaga" or alert level 3 on September 30, 2011. However, people settling near this mountain are advised not to feel anxious.

"For the community in Banten beach and other areas close to Anak Krakatau, they may stay calm. No need to panic," Head of Volcanology and Geological Disaster Mitigation (PVMBG) Surono told VIVAnews.com, on Monday.

According to Surono, currently the new danger zone has been set to within two kilometers from the volcano. "We have shut down Mount Anak Krakatau. Do not go there yet," he said.

Previously, based on observations from the monitoring post in Pasauran, Banten on Sunday, October 2, 2011, earthquakes took place up to thousands of times. From 12am to 6pm Indonesian Western Time (WIB) as many as 4,291 volcanic earthquakes, deep and shallow, were recorded. Such seismic activities are categorized as high.

Based on visual observation, there was no smoke or eruption. There was also no visible burst of incandescent materials either.

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Anak raised to level 4
2 Oct 11 – Mount Anak Krakatau has been raised to “standby” or level IV status after 2745 earthquakes struck the area by noon today, said Surono, of the Center for Volcanology and Geological Hazard Mitigation (PVMBG).

The quakes – which are now continuous – were felt along the entire island of Anak Krakatau, Surono added. The PVMBG recommends residents not to approach the mountain within a radius of 2 kilometers.

“We ask people coast of Banten and Lampung continue business as usual, do not panic, do not fall for the tsunami issue,” said Surono. “This is Anak Krakatoa erupted, not her mother (Krakatoa).”

There are currently six volcanoes in Indonesia on standby status, said Surono. Son of Krakatoa, Lokon, Karangetang, Papandayan, Tambora, and Children Ranakah.

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4 Oct 11 – Anak Krakatau (Child Of Krakatoa), a volcanic island between the islands of Java and Sumatra in Indonesia, erupted today propelling huge columns of ash and rock high into the air.

The Indonesian Volcanology and Geology Disaster Mitigation Centre reported that an estimated 6,000-7,000 volcanic earthquakes were recorded daily during the weekend and on Monday. Daily earthquake totals usually do not exceed 100-200.

Seismologists are still attempting to determine the type and scale of the ongoing eruption.

The eruption at Anak Krakatau is the biggest since January.

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Op woensdag 5 oktober 2011 12:04 schreef nodisch18 het volgende:
Gisteren nog een pubquiz verloren omdat een of andere onverlaat de uitbarsting van de Krakatau als grootste uitbarsting in de "recente geschiedenis" hanteerde in plaats van de Tambora

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Anak Krakatau trilt vijf keer per minuut
LAMPUNG - Mensen werkzaam op de observatiepost voor de Krakatau vulkaan in de Sunda Straat tussen de twee eilanden Java en Sumatra hebben bekend gemaakt dat het aantal trillingen in de vulkaan inmiddels is opgelopen tot vier a vijf per minuut. Gedurende woensdag waren er ruim 5.000 trillingen waar te nemen.

Andi Suardi, een van de medewerkers, zei dat er nog geen direct gevaar was voor een uitbarsting, al is eerder deze week wel de status van de vulkaan verhoogd naar alarmstatus drie op een schaal van vier. Dit is voornamelijk om toeristen en vissers uit de buurt van de vulkaan te houden.

Op dit moment vind er geen uitstoot van lava plaats door de vulkaan. Dit was eind vorig jaar nog wel het geval, toen barstte de vulkaan voor het laatst echt uit. Maar echt tot rust komen doet de vulkaan vrijwel nooit. Vaak is er nog iets van een rookpluim of kleine aswolk waar te nemen, dit terwijl de vullkaan dan vrijwel rustig is.

Suardi merkte wel op dat een grote hoeveelheid trillingen als nu wordt waargenomen geen karakteristieke eigenschap is van de Krakatau vulkaan. Er wordt dan ook verder onderzoek gedaan naar de mogelijke oorzaak van deze trillingen.

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Volcanic quakes around Krakatau continue to rise
REPUBLIKA.CO.ID, Cinangka - volcanic earthquake which occurred on Mt Anak Krakatau in the Sunda Strait continued to rise and up to now has reached 5883 compared to the previous day and 5204 times 5543.

"Volcanic earthquake which occurred on Mt Anak Krakatau on October 7, 2011 at 5. 883 times, and October 6 5543 times and the day before or on October 5 5. 204 times," said Chief Postal Pasauran Monitors GAK in the Village, District Cinangka, Serang, Banten, Anton S Pambudi, Saturday (8 / 10).

He explained that, despite an increase in seismicity in Gung Children Krakatu continues to increase, but Vulkanalogi Centre and Geological Hazard Mitigation (PVMBG) still sets the level III or Standby.

"We still assign the level of Mount Anak Krakatau Alert and we prohibit residents or tourists to get closer to the location of seismicity at a radius of two kilometers," he added.

He explained that the activity of Anak Krakatau Gung standby status since 30 September 2011 did not harm, all residents or anyone who already follow the recommendations issued by PVMBG.

"We hope people do not panic, because the earthquake that occurred on Mount Anak Krakatau, while not approaching the two-kilometer radius do no harm," he added.

Meanwhile, residents in coastal Anyer Beach claimed not to feel worried about the earthquake that occurred on Mount Anak Krakatau in the Sunda Strait. "My family and still feel comfortable, like Mount Anak Krakatau before re-defined level III," said resident Paku, Anyer, Doni.

According to Doni, his family are familiar with the conditions of seismicity of Mount Anak Krakatau is back at the level of alert. "Thank God, for level III of the status of Mount Anak Krakatau is not a scary thing happened. And we hope also on the status of this time does not pose a worrisome thing," he added.

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Krakatau stoot rookwolken uit
CINANGKA, BANTEN - De Anak Krakatau vulkaan in de Sunda Straat produceert opnieuw een kleine rookwolk. De wolk, met een hoogte van ongeveer 50 meter, kon dit maal prima gezien worden vanaf de observatiepost in Cinangka in de provincie Banten, aldus een medewerker van de observatiepost ter plekke.

Het hoofd van de observatiepost in Pasauran, Anton Tripambudi, zei zondag dat de rookwolken eerder dit jaar tot een hoogte van 200 meter reikten. "De observatiepost in Pasauran registreerde deze hoogte enkele weken geleden nog," aldus Tripambudi.

De kleur van de wolk was wederom wit. "De wolken zijn erg dun, net als gisteren," zei hij. Inwoners in de kustplaats Anyer zeiden dat de Krakatau vulkaan zelf vrij moeilijk te zien waren. "De rook kon vanaf het strnd niet goed worden gezien, dat was gisteren ook al het geval," zei Kusnadi, een inwoner.

Kusnadi zei ook dat de trillingen van de vulkaan nu af en toe ook te voelen waren, maar dat dit lang niet zo duidelijk was als vorig jaar het geval was. Toen dreigde de vulkaan uit te barsten en werd de alarm-status van de vulkaan verhoogd. Toen was ook de rook duidelijk te zien, aldus Kusnadi.

De trillingen zorgden vorig jaar ook regelmatig voor paniek onder inwoners omdat ramen regelmatig flink trilden. Een deel van de inwoners van Anyer heeft toen ook besloten om wat hogerop te gaan wonen uit angst voor een mogelijke tsunami.

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The height of Mount Anak Krakatau smoke this year's highest reaches 500 meters.

"Monitoring of Post Village Pasauran only see the smoke height of Mount Anak Krakatau as it is now the highest it reached 500 meters," he said.

As for the color of the smoke of Mount Anak Krakatoa itself, according to Anton, still the same as the day before: white. "Colors of thin white smoke, just like yesterday," he said. One resident Anyer, Arya, explaining, Mount Anak Krakatau smoke faintly visible.

He admitted, seismicity of Mount Anak Krakatau condition that rises from alert to standby is different from the year 2010. "If the previous year, when the Mount Anak Krakatau Standby stated, we can clearly see the smoke coming out from the belly of the mountain," says Arya

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Lava dome in Anak Krakatau grows steadily
An active lava dome is growing inside the summit crater of Krakatau volcano. Our tour expedition leader Andi just returned from a visit and reports that the dome is now about 100 m wide, and has 2 main active vents that eject jets of incandescent gas.

At night, the glow from the dome is clearly visible from Rakata and Sertung islands, and a continuous intense solfatara plume is rising about 500 m above the summit. Andi and our group observed also that there are now more and larger fumarole fields on the southern part of the cone. According to our observations and the opinion of local scientists, this area is inflated due to the pushing of the lava dome.

The seismic recordings from the observatory of Krakatau also show an increase in activity. On 26 March, there were 138 volcanic-tectonic (A-type) earthquakes and 300 long-period (B-type) quakes alone.

The question is how long the lava dome remains quiet and purely effusive in style. Explosive, also larger vulcanian-type ones, activity could occur any time.

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Op donderdag 29 maart 2012 17:43 schreef rubbereend het volgende:
plaatje doet het niet

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New vent has opened at the new lava dome of Anak Krakatau volcano
It appears that a new vent has opened at the new lava dome of Anak Krakatau volcano and started to emit ash, as Øystein Lund Andersen reports from a recent visit:

"The crater was illuminated by lava (dome) in the night, the location of the light is the southern part of the crater.

On the morning of the 7th April 2012 Anak Krakatau started to produce small eruptions from the southern part of the crater. The location of the eruption was on the same side of the crater, that of the growing lava dome, which several sources have reported about during the last few weeks. This might suggest a collapse of the Lava dome due to the eruptions that now are being seen? The eruption clouds only reached a height of 100-150meters and contained small amounts of ash and only a little rock fall.

The eruptions were not of an explosive character. The rest of the crater and its fumaroles are producing a continuous white cloud of steam/gas, rising to greater heights than the eruption clouds from the southern part of the crater. Additionally the southern/southwestern part of the upper flank does now have fields where steam can be seen rising, these fields did not emit steam during the last visit, an indication that magma is now located under this part of the cone."

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During our recent expedition to Krakatau volcano, we could no longer see the lava dome active during Feb-May this year. Probably, the magma column had dropped in mid to late May and the dome collapsed. At its place, there were only 2 collapse pits, very hot ground and intense degassing from numerous fumaroles inside and outside of the now large summit crater. Seismic activity when visiting the local volcano observatory was at very low levels, suggesting that Anak Krakatau is at the moment in a phase of repose. Interestingly, a number (at least four) areas with apparent submarine hydrothermal iron-bearing vents were observed that had not been there last year. In these areas, bubbling could be seen in the water, and where accessible, iron-rich greenish warm mud was found at the sea floor, which oxidized to orange when brought to the surface. The sea water around these areas had an intense yellow stain. Very similar submarine activity is known from around Nea Kameni Island, Santorini.