Volcanos and Volcanic Activity

[Astronuc]

Volcano prompts Peru evacuation

The authorities in Peru have declared a state of emergency around a volcano that has begun spitting ash and smoke after almost 40 years of inactivity.

The Ubinas volcano in southern Peru started erupting three weeks ago, killing livestock and polluting water.

http://news.bbc.co.uk/2/hi/americas/4935568.stm


Some background from 1998 - http://www.igp.gob.pe/volubi.html

[Astronuc]

View of the Ubinas volcano in Moquegua, some 1000 km south of Lima. Gas and cinder ejected by Ubinas volcano in southern Peru drove 200 persons from their homes and threatened 7,000 more, many of whom are reluctant to leave, officials said.

  - AFP, Friday, April 21, 2006

[Astronuc]

Mount Merapi is erupting in Indonesia

Thousands Flee Rumbling Indonesia Volcano

YOGYAKARTA, Indonesia - Indonesia ordered the immediate evacuation Saturday of thousands of people from the slopes of Mount Merapi volcano, warning of an imminent eruption as the mountain oozed fiery lava and belched clouds of black ash.

Background on Merapi -

http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13538

Back in April -

Frequent earthquakes and plumes of sulfur-laden gas indicated that Mt. Merapi was gearing up for an eruption in late April 2006. The volcano is one of Indonesia’s most active and dangerous volcanoes. The slopes of the volcano are densely populated, with four districts clustered on its flanks. As many as 80,000 people may be displaced if the volcano erupts, depending on which way the lava flows down the summit, reported the United Nations Office for the Coordination of Humanitarian Affairs (OCHA). Thousands of people who live near the volcano had been evacuated by April 27, and more were preparing to leave as the volcano continued to rumble. An eruption in 1994 claimed at least 66 lives, and a 1930 eruption killed 1,370.

Among the most serious dangers an erupting Merapi poses to the surrounding population are its characteristic pyroclastic flows and lahars. Avalanches of hot ash, gas, and rock sweep down the mountain at speeds of 100 kilometers per hour or more in a pyroclastic flow, accompanied or followed by volcanic mudflows—lahars. Pyroclastic flows and lahars have been responsible for much of the damage caused by the volcano during its long eruptive history.

Merapi (Smithsonian) - http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-25=

[Astronuc]

Pictures of Merapi eruption

http://news.yahoo.com/photos/sm/events/sc/080601volcano/p:5

[Astronuc]

Volcanoes are more or less thermal events, whereas earthquakes are primarily mechanical.

Now in areas like the Cascade mountain range in the US, it is believed that the mechanical energy of the subduction zone does cause tremendous heat - thermal energy - which leads to volcanoes, like Mt St Helens, Mt Hood, Mt Rainier, etc.  And the subduction zone experiences earthquakes.

Merapi and the big earthquke near Yogyakarta are the direct consequence of the interaction between the Australian and Asian techtonic plates.

This map shows the historical seismicity in the section of Indonesia near Yogyakarta -
http://neic.usgs.gov/neis/eq_depot/2006/eq_060526_neb6/neic_neb6_h.html

The orange and yellow colors indicate shallow (and more destructive) earthqukes on the southern coast of Java.  The blue and red indicate very deep earthquakes on the north side of Java.  The Volcanoes in Indonesia are distributed along the southern side of Java and Indonesia.

http://www.volcano.si.edu/world/region.cfm?rnum=06

http://volcano.und.edu/vwdocs/volc_images/img_java1.html

http://www.volcano.si.edu/world/region.cfm?rnum=0603

As a country with 129 active volcanoes spreading across the archipelago, Indonesia has frequently suffered from natural disaster associated with volcanic eruption which happen at least once a year. Due to this volcanic risk, geographical and meteorological, an effective method of monitoring  is required for those volcanoes.

The aim of all the monitoring methods is to reduce the impact of volcanic eruptions by establishing available early warnings, by mapping areas exposed to volcanological hazards, 
and taking timely preventive measures. 

Eighty of 129 volcanoes have been classified into A type according to their recorded-eruptions since 1600. Those are dotted across Sumatera (12 volcanoes), Java (21), Bali (2), Nusatenggara (20), Banda Sea (9), North  Sulawesi (6), Sangihe (5) 
and Halmahera (5).

  http://www.vsi.esdm.go.id/volcanoes/index.htm
http://www.vsi.esdm.go.id/picture/index.html

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New Scientiest, June 1 - The earthquake last weekend on the Indonesian island of Java, which killed thousands and left hundreds of thousands homeless, may be about to trigger a second disaster. The Volcanological Survey of Indonesia says that volcanic activity on nearby Mount Merapi has tripled since the quake.

There is normally thought to be no direct relationship between earthquakes and volcanoes, but it is possible for one to influence the other. "The earthquake epicentre was relatively close to Merapi, only around 50 kilometres away, so it is possible that the seismic activity did something to the magmatic plumbing system," says Brian Baptie, a seismologist at the British Geological Survey. "It is partially due to the kind of volcano it is. The lava dome is easily destabilised, with bits collapsing and forming pyroclastic flows."

 

[Astronuc]

Lava spewing in the crater of the 2,361 metre (7,746 ft) Mt. Karthala near Moroni, the capital of the Comoros Island, May 29, 2006.



http://www.peakbagger.com/peak.aspx?pid=11322

[Orstio]

http://news.yahoo.com/s/ap/20060812/ap_on_sc/philippines_volcano

LEGAZPI, Philippines - President        Gloria Macapagal Arroyo on Saturday visited villagers forced to flee their homes due to restive Mayon volcano and ordered officials to speed up efforts to improve conditions at cramped evacuation centers.

Scientists told Arroyo in a briefing that Mayon, the Philippines' most active volcano, appears to be gearing up for an explosive eruption since it began quietly oozing lava four weeks ago.

Following successive ash explosions on Monday, officials ordered a mass evacuation of villages on the southern and southeastern slopes of the volcano, which are the most vulnerable to a violent eruption.

[Astronuc]

Some background information -

http://volcano.und.edu/vwdocs/volc_images/southeast_asia/philippines/mayon.html
http://volcano.und.edu/vwdocs/current_volcs/philippines/mayonvol.html

http://vulcan.wr.usgs.gov/Volcanoes/Philippines/description_philippines_volcanoes.html

http://www.aenet.org/volcano/mayon.htm

http://earth.esa.int/ew/planning/pl_mayonvo(philippines)-aug06.htm

[Astronuc]

Tungurahua (Quichua tunguri (throat), rahua (fire): "Throat of Fire") is an active stratovolcano in Ecuador. It is situated in the Central Cordillera of the Ecuadorian Andes.

On July 14, 2006, Tungurahua started its most violent eruption since 1999. At around 6:00pm, the volcano spewed a 15 km column of ashes, vapor and rocks. The column drifted towards the Pacific Ocean and was clearly visible on satellite photos.

During the night and morning of July 15 constant tremors, explosions, ash emissions and rocks falls, put the population in Pelileo, Baños, Penipe, and other counties of the Provinces of Chimborazo and Tungurahua on alert. It is reported that lava flows damaged the road between Baños and Penipe. The ashes destroyed fields and calcined animals. As of July 17, it was reported that for the first time since 1999, pyroclastic flows had occurred, reaching the evacuated hamlet of Cusua and the Las Juntas bridge.

The activity continued slightly muted for one month, until August 16. On the morning of that day, at around 8:25 am, a huge explosion signaled the start of what appears to be the main event of this eruptive episode. An 8 km lava column arose from the crater. The volcano also spewed enormous quantities of hot rocks and ashes. Overnight, the whole province of Tungurahua, including Ambato, Pelileo, Baños and the province of Chimborazo including Riobamba and Penipe were covered with rocks and ashes. Some 200 sq. km (80 sq. miles) of crops have been destroyed.

http://en.wikipedia.org/wiki/Tungurahua
 
Summit Elevation: 5023 m (16,479 feet)
Latitude: 1.467°S  1°28'1"S
Longitude: 78.442°W 78°26'30"W

Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major volcanic edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II itself collapsed about 3000 years ago and produced a large debris-avalanche deposit and a horseshoe-shaped caldera open to the west, inside which the modern glacier-capped stratovolcano (Tungurahua III) was constructed. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. Prior to a long-term eruption beginning in 1995 that caused the temporary evacuation of the city of Baños at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925. 

http://www.volcano.si.edu/world/volcano.cfm?vnum=1502-08=

[remcook]

pretty volcano here:

http://www.esa.int/esaEO/SEMNX9C4VUE_index_0.html

[Astronuc]

Scientific Nature: Researchers Use Volcanic Eruption as Climate Lab

Earth's climate cannot be replicated in a lab. So to understand how this critical component of the planet's heat regulation works, scientists must rely on "natural experiments." Such natural experiments take apocalyptic form, such as the eruption of Mount Pinatubo in the Philippines in June 1991 that sent 10 cubic kilometers of ash, gas and other materials sky high. By tracking how this eruption affected the global climate--and determining how to trace its footprint in other records--scientists have turned the catastrophe into a tool for comprehension. "The big problem with climate--and trying to study it--is you can't play with it in the lab," says atmospheric scientist Joanna Futyan of Columbia University. "We were trying to use this abrupt event as a natural experiment: something dramatic happened and you can look at how the atmosphere responds to it."

Solar irradiance data on Mauna Loa indicate a transient cooling effect coincident with certain volcanic eruptions.

[Astronuc]

http://newsimg.bbc.co.uk/media/images/42627000/jpg/_42627381_stromboli_416_afp.jpg

Volcanic Italian island on alert
http://news.bbc.co.uk/2/hi/europe/6401701.stm

Emergency plans have been put into operation after two new craters opened on the summit of the volcanic Italian island of Stromboli.

One of the new lava streams created on the island, just north of Sicily, has already started flowing into the sea.

Coastguard patrol boats have been deployed and the population of 750 people has been urged to stay away from the danger areas.

The last major eruption in 2002 caused a collapse that led to a small tsunami.

The wave reached 10 metres (33ft) high and caused serious damage to Stromboli village on the north of the island.

Watch out!

[Astronuc]

Some amazing pictures.

http://volcano.und.edu/vwintl/vwintl.html

[Astronuc]

Perhaps the most famous volcano - Krakatoa or Krakatau Krakatao

http://en.wikipedia.org/wiki/Krakatoa