Sioux Falls Scientists endorse Krakatoa for describing
the most recent megavolcano explosion in 1883
which could be heard over 2,000 miles away.
Krakatoa (2005) - 90 minutes
Krakatoa at Amazon.com
On the morning of August 27, 1883, the rumbling volcano of Krakatoa stood more than 6,000 feet high, with a diameter of approximately 10 miles. Later that day, this giant cone exploded so violently it was literally blown away. The effects of the volcanic explosion caused a tidal wave more than 140 feet high; one ship was carried more than two miles inland. Hail-sized stones fell as far as 100 miles away, and the city of Jakarta fell into total darkness. For many of the area's inhabitants, Armageddon had arrived. Over 36,000 people were killed immediately, and countries all over the globe were affected by the volcano's devastating after-effects.
The eruption of Krakatoa was one of the best-documented natural cataclysms in history; from the first indications that something was amiss to the final explosion, each step was witnessed and recorded by the Dutch settlers living in the region. Krakatoa brings to life the story of this mammoth eruption, using dramatic recreation, contemporary documentary footage and breathtaking special effects.
10-2-19 Anak Krakatau volcano collapse: 'Warning signs were there'
Anak Krakatau, the Indonesian island volcano that collapsed last December triggering a huge tsunami, did produce clear warning signals before the event. That's the assessment of a German-led team which has reviewed all the data. The scientists say satellites in the months leading up to the catastrophe had observed increased temperatures and ground movement on the volcano. Earthquake and infrasound activity was also detected two minutes prior to the collapse of Anak's southwestern flank. When this mass slid into the sea, it sent a wall of water, up to 4m high, around the Sunda Strait. More than 400 people died in 22 December tragedy; a further 7,000 were injured and nearly 47,000 were displaced from their homes. Thomas Walter, from the German Research Centre for Geosciences GFZ in Potsdam, said any of the different signals viewed individually could not have been used to predict what happened at the island volcano, but taken together they might well have raised a red flag. "If you took any of the sensors on their own, the interpretation would not be robust, but by pulling together all of the different sensors we can draw a picture of the cascade that was going on," Dr Walter told BBC News. The team noted that the volcano was experiencing its greatest eruptive phase in 20 years in 2018; that its southwestern flank had begun edging seaward from January onwards; that there was an intense phase of thermal activity initiated on the 340m-high mountain in June, and that there had been an increase in the island's surface area in the months leading up to the collapse. There was also significant seismic behaviour just before the collapse. Perhaps an earthquake, maybe an explosion; it's not clear. But what was interesting, explained Dr Walter, was that this seismic signal did not go down to zero. And when it picked again, it displayed a low frequency that is characteristic of landslide behaviour. A couple of minutes further on in time, the frequency changes again, which the team interprets as a barrage of volcanic explosions - as "the cork comes off the top of the bottle". (Webmaster's comment: This is not a good place to live near.)
1-10-19 Anak Krakatau: Finnish radar satellite eyes tsunami volcano
Here's a new view of Anak Krakatau, the collapsed Indonesian volcano that generated the 22 December tsunami that devastated local coastlines. The picture was assembled from radar images acquired on Wednesday by the ICEYE-X2 satellite. This is a small innovative spacecraft from Finland that will soon be part of a large orbiting network of sensors. The volcano continues to evolve, following the cone's catastrophic failure. Its original height of 340m was reduced to just 110m in the disaster, but further eruptions have since begun to re-model the remnant structure. "This image indicates the edifice is in a building phase, with the crater no longer connected to the sea as it was in images from a week or so ago," observed Prof Andy Hooper from Leeds University, UK. More than 400 people died along the coastlines of Java and Sumatra in the Sunda Strait when the tsunami hit. Scientists relied heavily on radar satellites in the days immediately after the collapse to try to understand what had happened. Radar will see the ground day or night, and will even pierce thick cloud. Researchers were fortunate that the European Union's Sentinel platform passed overhead just hours after the event. But such observations are not always so timely. Helsinki-based ICEYE hopes to remedy this by putting up a constellation of small radar satellites. ICEYE-X2 is the second spacecraft to be launched. Another five to eight will go up this year. All these platforms are about the size of a suitcase - far smaller than the traditional radar sensors placed in orbit. (Webmaster's comment: To bad America's space program is focused on military objectives. Focused on ways to kill more people!)
1-3-19 Anak Krakatau volcano: Satellites get clear view of collapse
There is now some very good optical satellite imagery of the collapsed Anak Krakatau volcano, which generated the devastating tsunami on 22 December. Poor weather conditions over Indonesia's Sunda Strait had frustrated spacecraft that view the Earth in the same type of light as our eyes. But the team at Planet has managed to find windows in the cloud. Pictures from its Dove and SkySat platforms show the extent of the volcanic cone's failure. It is easier to appreciate now how the island has been reshaped. What was once a crater at the summit of a 340m-high edifice has been completely broken open to form a small bay. Indonesia's disaster agency says more than two-thirds of Anak Krakatau's volume (150-170 million cubic metres) is missing. Much of it is assumed to have slipped into the sea in the colossal landslide that produced the tsunami. Earth observation company Planet, which is based in San Francisco, operates one of the world's largest satellite constellations. The big network maximises the chances of seeing the ground when cloud clears above a target. Planet's small Dove spacecraft capture details on the ground larger than 3m - what is termed medium resolution; while its SkySat platforms have a high-resolution capability, capturing details larger than 72cm. The satellite pictures acquired immediately after the disaster came from radar spacecraft, and gave the first hints that Anak Krakatau had collapsed. Radar instruments can pierce cloud but they return a very different type of view to optical satellites, and need a particular skill to interpret. It's now thought some 430 people died along the coastlines of Java and Sumatra when the tsunami hit. Thousands more remain displaced.
12-29-18 Anak Krakatau: Indonesian volcano's dramatic collapse
The scale of the dramatic collapse of the Indonesian volcano that led to last Saturday's devastating tsunami in the Sunda Strait is becoming clear. Researchers have examined satellite images of Anak Krakatau to calculate the amount of rock and ash that sheared off into the sea. They say the volcano has lost more than two-thirds of its height and volume during the past week. Much of this missing mass could have slid into the sea in one movement. It would certainly explain the displacement of water and the generation of waves up to 5m high that then inundated the nearby coastlines of Java and Sumatra. The Centre of Volcanology and Geological Hazard Mitigation (PVMBG) has been studying pictures from a number of radar satellites, including the European Union's Sentinel-1 constellation and the German TerraSAR-X platform. Radar has the advantage of being able to see the ground day or night, and to be able to pierce cloud. The capability has allowed some initial measurements to be made of Anak Krakatau's lost stature, in particular on its western side. What was once a volcanic cone standing some 340m high is now just 110m tall, says the PVMBG. In terms of volume, 150-170 million cubic metres of material has gone, leaving only 40-70 million cubic metres still in place. Quite how much mass was lost on 22 December itself and how much in the following days is unknown. Scientists may have a better idea once they have had a chance to visit the volcano and conduct more extensive surveys. But with the eruptions still ongoing and a safety exclusion zone in force - no-one is going near Anak Krakatau. (Webmaster's comment: This story will play out over the coming centuries if not millennia.)
12-23-18 Indonesia tsunami kills hundreds after Krakatau eruption
More than 220 people have been killed and 843 injured after a tsunami hit coastal towns on Indonesia's Sunda Strait, government officials say. There was no warning of the giant waves which struck at night, destroying hundreds of buildings, sweeping away cars and uprooting trees. It is thought undersea landslides from the Anak Krakatau volcano caused them. President Joko Widodo has expressed his sorrow for the victims and urged people to be patient. The Sunda Strait, between the islands of Java and Sumatra, connects the Java Sea to the Indian Ocean. The disaster management agency has warned people to stay away from the coastline due to fears of another tsunami. Saturday's tsunami struck at about 21:30 local time (14:30 GMT), during a local holiday. It hit several popular tourist destinations including the Tanjung Lesung beach resort in the west of Java island. Red Cross official Kathy Mueller told the BBC: "There is debris littering the ground, crushed cars, crushed motorcycles, we're seeing buildings that are collapsed." It appears that the main road into Pandeglang has been badly damaged, making it difficult for rescuers to reach the area, she added. Eyewitness Asep Perangkat said cars and containers had been dragged about 10 metres (32 feet). "Buildings on the edge of [Carita] beach were destroyed, trees and electricity poles fell to the ground," he told AFP news agency. Officials say more than 160 people were killed in Pandeglang - a popular tourist district on Java known for its beaches and national park. Meanwhile, 48 were reported dead in South Lampung on Sumatra, and deaths were also reported in Serang district and Tanggamus on Sumatra. Officials fear the death toll could rise further. (Webmaster's comment: Krakatoa will not go away. It would be good to live someplace on high ground.)
12-23-18 Indonesia tsunami: How a volcano can be the trigger
Nobody had any clue. There was certainly no warning. It's part of the picture that now points to a large underwater landslide being the cause of Saturday's devastating tsunami in the Sunda Strait. Of course everyone in the region will have been aware of Anak Krakatau, the volcano that emerged in the sea channel just less than 100 years ago. But its rumblings and eruptions have been described by local experts as relatively low-scale and semi-continuous. In other words, it's been part of the background. And yet it is well known that volcanoes have the capacity to generate big waves. The mechanism as ever is the displacement of a large volume of water. Except, unlike in a classic earthquake-driven tsunami in which the seafloor will thrust up or down, it seems an eruption event set in motion some kind of slide. It is not clear at this stage whether part of the flank of the volcano has collapsed with material entering the sea and pushing water ahead of it, or if movement on the flank has triggered a rapid slump in sediment under the water surface. The latter at this stage appears to be the emerging consensus, but the effect is the same - the water column is disturbed and waves propagate outwards. Tide gauges in the Sunda Strait indicate high water around half an hour after Anak Krakatau's most recent eruptive activity at roughly 21:00 local time (14:00 GMT) on Saturday evening. Prof Dan Parsons from Hull University, UK, told BBC News: "The sides of volcanoes, the flanks, are notoriously unstable and it looks like a landslip movement into, or below, the sea has resulted in the generation of a significant tsunami. "[The original Krakatoa volcano] exploded and destroyed itself in 1883 and since then has been building again slowly. As volcanoes build, their sides can become unstable and collapse even without any volcanic activity. As the slide displaces water it generates a large wave - the same way as if you enter a bath from one side too quickly."
12-20-18 Warning against 'volcano tourism' risks
Thrill-seeking tourists are putting themselves in danger and hampering emergency services by heading towards volcanoes when they erupt. A report from the Royal Geographical Society warns of the growing risks caused by "volcano tourism". Emergency authorities in countries such as Iceland now have to contend with the arrival of tourists who rush there to get close to an exploding volcano. The study says such tourists fail to understand the seriousness of the risk. The study, published by the Royal Geographical Society and written by University of Cambridge geographer Amy Donovan, warns that such visitors can create dangerous problems for already stretched rescue services. "You can breathe the gas, hear the sounds the earth is making. They want to get closer to feel the power of the earth," she says. At the extreme end, she says there are so-called "volcanophiles" who chase exploding volcanoes around the world. She says the increase in volcano tourism could be driven by the rise of mobile phones, where people want to be able to record themselves in such dramatic settings. But they also fail to realise the great danger they could face. There are injuries from people being hit by chunks of rock or lava bombs. Or else people might get close to a "fire fountain" and not realise there could be poisonous gases (Webmaster's comment: More Stupid People are born every minute.)
Sioux Falls Scientists endorse Krakatoa for describing
the most recent megavolcano explosion in 1883
which could be heard over 2,000 miles away.