Soputan volcano erupts

Lava from Mount Soputan flows 2 km from crater

Indonesia’s Vulcanology Survey raised alert level for Soputan volcano located on Sulawesi island to level IV, the highest level, after it began ejecting hot lava and clouds of ash. Pyroclastic flows were extending about 2 km from Mount Soputan’s summit, but haven’t reached the foot of the mountain.

The authorities placed a 6-km exclusion zone around the volcano. Climbers are not allowed in the danger zone which also covers camping areas in the eastern part of the mountain about 4 km from the summit. According to a report, 6 volcanic earthquakes struck Mount Soputan on June 6.

People from a district in Minahasa look at columns of ash spewed from Mount Soputan, in Indonesia’s North Sulawesi province June 6, 2008. REUTERS/Stringer. Image may be subject to copyright. See FEWW Fair Use Notice!

“Stronger explosion may happen, which can emit dangerous materials from the crater,” Saut Simatupang, head of Indonesia’s Vulcanology Survey said.

The volcano has been erupting since Friday, spewing ash and debris to a height of about 2 km and covering an 8-km radius area around the crater.

“There is no need to displace the villagers. The frequency of the eruption has decreased since 2 a.m. Saturday,” he said.

Although no casualties have been reported, an eye witness in the village of Molompar in the Tombatu subdistrict in Southeast Minahasa, reported that a number of houses in Lobu, Silian, and Tombatu villages had collapsed as a result of volcanic ash deposits that had accumulated on the roofs.

Mount Soputan, a stratovolcano, is one of Indonesia’s 130 or so active volcanoes, which previously erupted 24–30 October 2007. In a 2004 eruption lava extended its southwest slope, but no fatalities were reported.

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A New Era of Intense Volcanic Unrest May Have Begun

Where Could The Next Supervolcanic Eruption Occur?

1. Pico del Teide?
2. Mauna Loa?
3. Mount Vesuvius?
4. Mount Rainier?
5. Taal?
6. Thera?

Volcanoes

A volcano is an opening in a planet’s crust that allows ash, gases and molten rock to escape from below the surface.

Volcanoes are generally found where tectonic plates converge or divrge. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by “divergent tectonic plates” pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by “convergent tectonic plates” coming together.

Author:MesserWoland via Wikimedia Commons.This file is licensed under the Creative Commons Attribution ShareAlike license versions 2.5, 2.0, and 1.0

Cross-section through a stratovolcano:

1. Large magma chamber ◊ 2. Bedrock ◊ 3. Conduit (pipe) ◊ 4. Base ◊ 5. Sill ◊ 6. Branch pipe ◊ 7. Layers of ash emitted by the volcano ◊ 8. Flank ◊ 9. Layers of lava emitted by the volcano ◊ 10. Throat ◊ 11. Parasitic cone ◊ 12. Lava flow ◊ 13. Vent ◊ 14. Crater ◊ 15. Ash cloud

Eruption Types

There are many different kinds of volcanic activity and eruptions: phreatic eruptions (steam-generated eruptions), explosive eruption of high-silica lava (e.g., rhyolite), effusive eruption of low-silica lava (e.g., basalt), pyroclastic flows, lahars (debris flow) and carbon dioxide emission. All of these activities can pose a hazard to humans. Earthquakes, hot springs, fumaroles, mud pots and geysers often accompany volcanic activity. (Source)

Image by USGS

The concentrations of different volcanic gases can vary considerably from one volcano to the next. Water vapor is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide. Other principal volcanic gases include hydrogen sulfide, hydrogen chloride, and hydrogen fluoride. A large number of minor and trace gases are also found in volcanic emissions, for example hydrogen, carbon monoxide, halocarbons, organic compounds, and volatile metal chlorides.

Large, explosive volcanic eruptions inject water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and ash (pulverized rock and pumice) into the stratosphere to heights of 16–32 kilometres (10–20 mi) above the Earth’s surface. (Source)

Decade Volcanoes

The Decade Volcanoes are 16 volcanoes identified by the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) as being worthy of particular study in light of their history of large, destructive eruptions and proximity to populated areas. The Decade Volcanoes project encourages studies and public-awareness activities at these volcanoes, with the aim of achieving a better understanding of the volcanoes and the dangers they present, and thus being able to reduce the severity of natural disasters. They are named Decade Volcanoes because the project was initiated as part of the United Nations sponsored International Decade for Natural Disaster Reduction. (Source)

The 16 current Decade Volcanoes

Avachinsky–Koryaksky, Kamchatka, Russia Colima, Jalisco and Colima, Mexico Mount Etna, Sicily, Italy Galeras, Nariño, Colombia Mauna Loa, Hawaii, USA Mount Merapi, Central Java, Indonesia Mount Nyiragongo, Democratic Republic of Congo Mount Rainier, Washington, USA

Sakurajima, Kagoshima Prefecture, Japan Santamaria/Santiaguito, Guatemala Santorini, Cyclades, Greece Taal Volcano, Luzon, Philippines Teide, Canary Islands, Spain Ulawun, New Britain, Papua New Guinea Mount Unzen, Nagasaki Prefecture, Japan Vesuvius, Naples, Italy

Mount St. Helens shortly after the eruption of May 18, 1980

1 km steam plume ejected from Mount St. Helens photo taken by USGS on May 19, 1982 [Mount St. Helens is located in Skamania County, Washington, in the Pacific Northwest region of the United States.]

Mount St. Helens is most famous for its catastrophic eruption on May 18, 1980, which was the deadliest and most economically destructive volcanic event in the history of the United States. Fifty-seven people were killed; 250 homes, 47 bridges, 24 km of railways, and 300 km of highway were destroyed. The eruption caused a massive debris avalanche, reducing the elevation of the mountain’s summit from 2,950 to 2,550m and replacing it with a 1.5 km-wide horseshoe-shaped crater. The debris avalanche was up to 2.9 km³ in volume (VEI = 5). (Source)

A large eruption at Mount Etna, photographed from the International Space Station

Mount Etna, Sicily . Last Eruption 2007. [Photo Credit: Josep Renalias, via Wikimedia commons]
This file is licensed under the Creative Commons Attribution ShareAlike 2.5

Koryaksky Volcano seen in the background. Last Eruption: 1957. GNU Free Documentation License, Version 1.2 or any later version. See file detail.

Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station.

Mount Nyiragongo volcano, Virunga Mountains, the Democratic Republic of the Congo. [The main crater is 250 m deep, 2 km wide and sometimes contains a lava lake. Nyiragongo and nearby Nyamuragira are together responsible for 40% of Africa’s historical volcanic eruptions. (Source: USGS) Last Eruption: 2008 (continuing)

The three summits of Mount Rainier: Liberty Cap, Columbia Crest, and Point Success [Last Eruption 1854]

The snow-capped summit of Pico del Teide in December 2004 – Active but dormant volcano, Tenerife, Canary Islands. Last eruption 1909. Photo: M. D. Hill. This work is licensed under the Creative Commons Attribution 2.5 License.

An aerial photo of Vesuvius. last Eruption 1944 [Author: Pastorius? Via Wikimedia Commons. ] This file is licensed under Creative Commons Attribution 2.5 License

Taal Volcano seen from across Taal Lake on the island of Luzon in the Philippines. Last Eruption: 1977.

Supervolcanoes: Nature’s “Thermonuclear” Arsenal

Satellite image of Thera, November 21, 2000. The Minoan caldera is at the lower part of the image and formed in the Minoan eruption 1630 and 1600 BCE. The whole caldera is formed of three overlapping calderas.

The Minoan eruption of Thera, also referred to as the Thera eruption or Santorini eruption, was a major catastrophic volcanic eruption (VEI = 6, DRE = 60 km3) which is estimated to have occurred in the mid second millennium BCE. The eruption was one of the largest volcanic events on Earth in recorded history. The eruption destroyed most of the island of Thera, including the Minoan settlement at Akrotiri as well as communities and agricultural areas on nearby islands and on the coast of Crete. The eruption contributed to the collapse of the Minoan culture.

The eruption caused significant climatic changes in the eastern Mediterranean region, Aegean Sea and much of the Northern Hemisphere. There is also evidence that the eruption caused failure of crops in China, inspired certain Greek myths, contributed to turmoil in Egypt, and influenced many of the biblical Exodus stories. It has been theorized that the Minoan eruption and the destruction of the city at Akrotiri provided the basis for or otherwise inspired Plato’s story of Atlantis. (Source)

Volcanic craters on Santorini. This file is licensed under Creative Commons Attribution 2.5 License [ photo: Rolfsteinar, via Wikimedia Commons]

Lake Taupo is a lake situated in the North Island of New Zealand. It has a perimeter of approximately 193km, a deepest point of 186 m and a surface area of 616 square km.

The lake lies in a caldera created following a huge volcanic eruption (see supervolcano) approximately 26,500 years ago. According to geological records, the volcano has erupted 28 times in the last 27,000 years. It has predominantly erupted rhyolitic lava although Mount Tauhara formed from dacitic lava.

The largest eruption, known as the Oruanui eruption, ejected an estimated 1,170 km³ of material and caused several hundred square kilometres of surrounding land to collapse and form the caldera. The caldera later filled with water, eventually overflowing to cause a huge outwash flood.

NASA satellite photo of Lake Taupo

Several later eruptions occurred over the millennia before the most recent major eruption, which occurred in 180 CE. Known as the Hatepe eruption, it is believed to have ejected 120 km³ of material, of which 30 km³ was ejected in the space of a few minutes. This was one of the most violent eruptions in the last 5,000 years (alongside the Tianchi eruption of Baekdu at around 1000 and the 1815 eruption of Tambora), with a Volcanic Explosivity Index rating of 7. The eruption column was twice as high as the eruption column from Mount St. Helens in 1980, and the ash turned the sky red over Rome and China. The eruption devastated much of the North Island and further expanded the lake. Unlike today, the area was uninhabited by humans at the time of the eruption, since New Zealand was not settled by the Māori until several centuries later. Taupo’s last known eruption occurred around 210 CE, with lava dome extrusion forming the Horomatangi Reefs. (Source)

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Chaitén Volcano Still Active

*** Breaking News: May 19, 2008 Philippines Taal Volcano Could Erupt Anytime!

Update #2 Chaitén Volcano –

Chile President: Ash-Covered Towns Could Be Permanent Ghost Towns

A segment of the pyroclastic tower ejected from the Chaitén volcano has fallen on the surroundings areas amid the eruptive activities that began 8 days ago.

Chilean President Michelle Bachelet warned that towns surrounding Chaitén Volcano could become permanently uninhabitable. Bachelet’s remarks follows a report by National Geologic and Mining Service (SERNAGEOMIN) which forecast probability the volcano’s collapse at more than 50 percent.

The increased build-up of pyroclastic material in the magma dome made it prone to collapse, SERNAGEOMIN said. An implosion could result in the “complete destruction of everything within a 15 kilometer radius around the peak, an area which encompasses Chaitén, Santa Barbara, and several rural farming villages.”

According to vulcanologist Luis Lara Chaitén volcano could implode releasing a streams of red-hot pyroclastic material which would destroy everything in its path. (Source)

What goes up must come down! Ash from eruption settles on the surrounding area
Photo by Victor Gonzalez, Partido Humanista. Image may be subject to copyright. See FEWW Fair Use Notice.

“Right now, everything is grey,” said Futaleufu Mayor. “We’ve got a huge layer of ash that a passing rain has turned into cement-hard” (Photo: AP) Image may be subject to copyright. See FEWW Fair Use Notice.

Chaiten and other towns in the area are covered in ash (Photo courtesy of Victor González, Partido Humanista) Source: Patagonia Times. Image may be subject to copyright. See FEWW Fair Use Notice.

Pyroclastic ash spewed two miles into the air (Source Dailymail UK). Image may be subject to copyright. See FEWW Fair Use Notice.

A dead cow lies covered by ashes from the Chaiten volcano at a road leading to Argentina near Chaiten, Chile. (Photo and caption FoxNews!) Image may be subject to copyright. See FEWW Fair Use Notice.

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• The First Wave of World’s Collapsing Cities
• Ghost towns

::

Mt Ruapehu Eruption Alert

Submitted by a reader

Will one or both of New Zealand islands break up and sink in the south-western Pacific Ocean?

Update [June 30, 2008]: Ruapehu crater lake temperatures remain high

Increased risk of eruptions on Mt Ruapehu

Scientists are alarmed by an increased risk of eruptions on Mt Ruapehu. Climbers are warned about the increased gas concentrations near the Ruapehu’s crater lake that will affect some people.

In a moderate-sized eruption last year, William Pike, a geography teacher, lost part of his leg after a lahar partially buried him under tons of debris.

The crater lake temperature normally rises and drops in regular cycles. However, since the last eruption, the temperatures have remained above the of 34 – 38 °C range, a Conservation Department scientist said.

“Since September there’s been a long period of heating in the volcano, which is unusual. Normally the crater lake temperature goes up and down every nine to 15 months.

“But it has been hovering around 34-38 degrees when it normally should be lower than this.

“Basically, the temperature has stayed hot for longer this time.

“There’s no clear pattern – before the last two eruptions it was at the bottom of the cycle.”

Predicting how close the mountain was to erupting involves monitoring numerous factors, especially the crater lake temperature, the scientist said.

“It’s a combination of gas, lake temperature and magma temperature… We are issuing a warning that people should be alert if they go into the summit hazard zone.” (Source)

A train passes over a bridge over the Whangaehu River at the scene of the historic Tangiwai Rail incident after a mud flow from the crater lake of Mount Ruapehu, in the central North Island, New Zealand, Sunday, March 18, 2007. A potentially lethal mix of mud, acidic water and rocks tore down the slope of New Zealand’s Mount Ruapehu on Sunday, emergency officials said, but there was no immediate threat to life. Credit: AP Photo/NZPA, Stephen Barker (Source and Caption: Live Science) Image may be subject to copyright. See Fair Use Notice!

What’s a Lahar?

A lahar is a type of mudflow composed of pyroclastic material and water that flows down from a volcano, typically along a river valley. The term ‘lahar’ originated in the Javanese language of Indonesia.

Lahars have the consistency of concrete: fluid when moving, then solid when stopped. Lahars can be huge: the Osceola lahar produced 5,600 years ago by Mount Rainier in Washington produced a wall of mud 140 metres (460 ft) deep in the White River canyon and extends over an area of over 330 square kilometres (130 sq mi) for a total volume of 2.3 cubic kilometers (0.55 cubic miles).

Lahars can be extremely dangerous, because of their energy and speed. Large lahars can flow several dozen meters per second and can flow for many kilometres, causing catastrophic destruction in their path. The lahars from the Nevado del Ruiz eruption in Colombia in 1985 caused the Armero tragedy, which killed an estimated 23,000 when the city of Armero was buried under 5 metres (16 ft) of mud and debris. The 1953 Tangiwai incident in New Zealand was caused by a lahar. (Source)

Photo Credit: N. Banks on December 18, 1985 (USGS)

The only remaining buildings in Armero, Colombia, 72 km dowstream from Nevado del Ruiz volcano, destroyed and partially buried by lahars on November 13, 1985. Lahars reached Armero about 2.5 hours after an explosive eruption sent hot pyroclastic flows across the volcano’s broad ice- and snow-covered summit area. Although flow depths in Armero ranged only from 2 to 5 m, three quarters of its 28,700 inhabitants perished. (Caption: USGS)

Plate tectonics

Plate tectonics is a theory of geology that explains the observed evidence for large scale movements of the Earth’s lithosphere. The theory encompassed and superseded the older theory of continental drift from the first half of the 20th century and the concept of seafloor spreading developed during the 1960s. (Source)

The tectonic plates of the world (as of second half of the 20th century). (USGS)

Convergent boundary

In plate tectonics, a convergent boundary – also known as a convergent plate boundary or a destructive plate boundary – is an actively deforming region where two (or more) tectonic plates or fragments of lithosphere move toward one another and collide. (Source)

Will a magnitude 9.8 (M_W) earthquake centered at 42° 00′ 59″ South, 175° 05′ 07″ East herald the end of New Zealand Islands?

New Zealand’s Alpine Fault. Image may be subject to copyright. SEE Fair Use Notice!

Topography of New Zealand (NASA Visible Earth)

Credit: NASA Image courtesy JPL/National Geospatial-Intelligence Agency

New Zealand straddles the juncture of the Australian and Pacific tectonic plates. The Australian Plate is on the west side of the boundary, while the Pacific Plate is on the eastern side. The two plates converge in a scissor-like pattern. In the northern part of the boundary, the Australian plate overrides the Pacific plate, and in the southern part of the plate boundary, the Pacific plate overrides the Australian plate. New Zealand sits in the area around the cross point of this tectonic scissor pattern. (For help visualizing the process, take two index cards and arrange them side by side. On the left-hand card make a cut from the middle of the right edge toward the center. Lift up the top “flap” created by the cut and slide the right-hand card into the cut. Let go of the flap. The left-hand card is the Australian Plate; the right-hand card is the Pacific Plate.)

The collision of the two plates has built two major islands that together exhibit active volcanoes and fault systems, and these geologic features are very evident in the topographic pattern. The image above shows a topographic map of the North and South Islands of New Zealand made from radar data collected by the Space Shuttle Endeavor. Elevation is color-coded, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Shading reveals the direction of slopes. Northwest slopes appear bright, and southeast slopes appear dark.

The North Island lies at the southern end of the west-over-east (Australian over Pacific) plate convergence. Here, the Pacific plate dives under the North Island, and the immense heat and pressure created by this subduction process melts the deep rock. The melted rock (magma) rises to the surface through the North Island’s volcanoes and other geothermal features. Most notable are Mount Egmont on the west coast, and Mounts Ruapehu, Ngauruhoe, and Tongariro, clustered just south of the island’s center. The Rotorua geothermal field is northeast of that cluster of volcanoes, and the field appears as a scattering of bumps created by smaller volcanic eruptions.

The South Island straddles the “cross point” of the subduction scissor pattern. To the north of the cross point, the Pacific Plate goes under the Australian Plate; to the south of the cross point, it goes over top. This area around this cross point is not in either subduction zone, which explains why it lacks the volcanic activity of the North Island.

Instead, South Island features a fault system that connects the northern subduction zone to the southern one, which occurs south of South Island. The Alpine fault is the major strand of this fault system along most of the length of the island, near and generally paralleling the west coast. Its impact upon the topography is unmistakable, forming an extremely sharp and straight northwest boundary to New Zealand’s tallest mountains, the Southern Alps. Along the Alpine Fault, the plates are sliding past each other (moving horizontally) somewhere between 35-40 millimeters per year. Vertical differences between the two plates increase at a rate of about 7 millimeters per year, which is consistent with the ongoing uplift of the Southern Alps.

Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth’s surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., for NASA’s Earth Science Enterprise, Washington, D.C.  Caption: Visible Earth.

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