VOLCANO PLANET

The Volcan Fuego in Guatemala is always going off and it's one of Central America's most active volcanoes but this weekend, it's activity grew intensive. On the evening of 17th May 2012, a new lava flow was reported flowing down from the eastern edge of the crater towards the Las Lajas canyon with a length of 300m and constant degassing was also reported. The number of explosions had also increased, and degassing and rumbling was reported to occur for durations of 15 minutes. On 18th May 2012, explosions increased to intervals of 5 to 10 minutes.

In the early hours of 19th May 2012, CONRED issued an orange alert for the volcano due to the increase in intensity of activity which had fed a 500m long lava flow on the west side of the volcano. From 2:45am (local time) more activity had increased, and explosions were reported to reach a height of 400m above the crater from 6:30am (local time) and seismic activity had increased. An ash column reached heights of 5000m above the crater and extended 25km to 30km southwest. A lava flow 600m long was observed to the southwest and another lava flow in the Las Lajas canyon reached the base of the volcano. Pyroclastic flows were observed, and the National Highway 14 was closed to the Las Lajas bridge. Later that day, the intensity had slightly decreased and the National Highway 14 was opened for 15 minutes every time whilst being reclosed for another hour each time, and 15 to 20 explosions per minute was recorded. The intensity of the activity later decreased although the volcano was still being monitored closely.

The beginning of the lava flow during the early phase of the intensive activity. PHOTO SOURCE: CONRED

Pyroclastic flow observed during the morning of 19th May 2012. PHOTO SOURCE: CONRED

Activity caught on camera. VIDEO SOURCE: BlueBayouGuate/Youtube

According to the website of Virunga National Park, the Nyamuragira Volcano in the Democratic Republic of Congo has been showing new signs of activity. Beginning on 24th February 2012 the Goma Volcano Observatory picked up some seismic events which were said to be explosion quakes coming from the summit crater area. While the activity was increasing within the crater since then, the flank eruption which began last November had decreased significantly. In March, the crater began to emit a steam/gas plume and a strong smell of sulphur dioxide was reported. During April, overflight observations revealed a pit crater which was degassing had become more active. Volcanologists believe that the activity could either be related to the draining of magma below, or it could be the start of a new phase of activity.

Overflight observation shows a degassing pit crater in the summit crater of Nyamuragira. PHOTO SOURCE: gorillacd.org

A new paroxysm occurred on Etna during the early hours of 24th April 2012 (local time) after being preceded by lava flow emissions followed by strombolian explosions during the evening of 23rd April 2012, which had then as usual became a paroxysmal episode.

Here's the video of it which was shot by Klaus Dorschfeldt.

CENAPRED in Mexico has raised the alert level of Popocatepetl to Yellow Phase 3 following an increase of activity since a few days. Since 13th April 2012 ash plumes have been emitted 1km, 1.5km, and 2km above the crater and ashfall was reported in various towns including Puebla, San Pedro Benito Juarez, Santiago Xalitzintla, Tianguismanalco, and Atlixco. 30 communities reported ashfall as thick as 7cm. Explosions were also reported including on the 13th and 14th April 2012 when incandescent blocks was ejected 500m-800m from the crater rim by huge explosions.

I leave you with an image of a compilation of today's webcam shots.

A phreatic eruption has occurred on Costa Rica's Rincon de la Vieja Volcano during the afternoon of 14th April 2012 and was reported to have been heard and witnessed by locals. Sediments were seen to have spewed resulting in a large steam plume rising above the crater. The material thrown out from the acid lake flowed down a slope by the external northern crater wall and into some lahar channels.

Phreatic eruption resulted in a steam plume. PHOTO SOURCE: Greeisyn Yanela Zamora Ugarte

Seismic activity recorded from the eruption. IMAGE SOURCE: OVSICORI-UNA

Etna erupted again today during the afternoon making it the 24th paroxysm since the series of paroxysms began in January 2011.

Here's a video of today's paroxysmal episode by latino70 (Youtube):

On 11th April 2012, the Banda Aceh province in northern Sumatra, Indonesia suffered another powerful earthquake just like it did back on Boxing Day 2004. A magnitude 8.7 on the richter scale was recorded causing panic among the local population. Not taking any chances, the people of Banda Aceh immediately evacuated for higher ground fearing a repeat of the 2004 tsunami which had caused devastation. Some strong aftershocks especially that of 8.7, 8.2, and 6.5 magnitude also occurred. A tsunami warning was imposed across the Indian Ocean especially in Thailand and India but was soon lifted a few hours later. It was said that due to the nature of the earthquake a tsunami did not materialise.

Indonesia is an archipelago which lies close to the edge of the subduction zone on the boundary of the Australian and Eurasian tectonic plates.

Yesterday, an eruption begun on Soufriere Hills Volcano on the Carribean island of Montserrat at around 8am local time. Mild ash venting had occurred within the 11th February 2010 collapse scar to the south of Old English's crater wall, and the eruption was said to be of Phreatic type. Ash rose to the height of 6000ft above sea level. A new fumarole was also discovered to the northwest of the dome behind Gage's Mountain.

Photo of the ash venting with the new fumarole on the right. PHOTO SOURCE: Montserrat Volcano Observatory/Flickr.

Tungurahua in Ecuador began a new eruption yesterday afternoon (local time) following seismic tremors and the emissions of steam and ash. Moderate to strong roaring noises were in areas near the volcano and the ash plume was reported to have drifted towards the southwest. During the night, strombolian fountains rising up to 500m above the crater and the expulsion of incandescent rocks was observed especially to the northwest. Low intensity sporadic roaring was reported and ashfall was reported in Choglontus and Manzano.

Ash emissions on Tungurahua just seen above the clouds on 3rd March 2012. PHOTO: J. Bustillos/IGEPN

Meanwhile over in Sicily, the third paroxysm of the year had occurred on Etna this morning following 18 days of weak strombolian activity from the New Southeast Crater. Eruptive vents had opened up on the southwestern and northern flanks of the cone which in turn emitted lava flows which had interacted violently with the snow on the ground. Pyroclastic flows were generated which reached lengths of a few hundred metres and a lahar caused by the rapid melting of thick snow descended into the Valle del Bove. The paroxysm lasted until the mid morning.

Etna eruption on the morning of 4th March 2012. VIDEO: mikyjimny/Youtube

Mainland India does not contain any volcanoes during the present day but however, evidence of prehistoric volcanic activity is found there in an area in west-central India, the Deccan Traps. However, this is not to say that the whole of India hasn't got any volcanoes because there are two in fact, Narcondum and Barren Island which are both located within the Andaman Islands. The Andaman Islands are an Indian administered achipelago which is located to the north of the Indonesian island of Sumatra, and they lie on the junction of the Indian, Australian, and Eurasian tectonic plates. A submarine volcanic eruption was also reported near Pondicherry off the east coast of mainland India in 1757 but the Geological Survey of India did not confirm this so it remains uncertain.

Map showing location of India and the Andaman Islands. IMAGE SOURCE: USGS

The Deccan Traps is a large igneous province made up of flood basalts and is one of the largest volcanic provinces in the world. It consists of flat overlying basaltic lava flows which is as much as 2000m thick and covers an area of 200,000 square miles. It is said that the Indian tectonic plate was passing over the Reunion mantle plume around 60 to 68 million years ago and it was estimated to have erupted 12,275 cubic miles of basaltic lava which formed the Deccan Traps estimated to have originally covered an area of 600,000 square miles. Tholeiitic basalts account for 95% of the lavas erupted but other types of rock which was found included: Alkali basalts, Nephelinites, Lamprophyre, and Carbonatites.

Diagram showing location of Deccan Traps and the movement of the Reunion mantle plume. IMAGE SOURCE: Elaine Meinel Supkis

Geological features of the Deccan Traps. PHOTO SOURCE: Wikipedia

A valley in the Deccan Traps. PHOTO SOURCE: Wikipedia

Narcondum is one of the two volcanoes within the Andaman island arc. This 710m high andesitic stratovolcano lies north of the active Barren Island volcano and is densely vegetated and is capped by three peaks. There have been no historical eruptions of the volcano although there were unconfirmed reports of smoke and mud being ejected after the great Asian earthquake of 2004 but was later found to be false. The island's name means "pit of hell" but it is said that it may have been mistakenly given in confusion with the active Barren Island volcano. Narcondum is also home to the Narcondum Hornbill, an endangered species of bird said to have evolved from the Wreathed Hornbill.

View of Narcondum Island. PHOTO SOURCE: coastview/Panoramio

Cliffs around Narcondum Island. PHOTO SOURCE: aussicat/Panoramio

The other volcano within the Andaman Island arc is Barren Island, India's only active volcano. Located 135km northeast of the Andaman Islands capital Port Blair and rising 354m above sea level, Barren Island is a summit of a stratovolcano which rises from the depth of approximately 2250m below sea level and has a width of 3km wide. The island contains a 2km wide caldera open to the west which was created during a major explosive eruption in the late Pleistocene and has a central pyroclastic cone and caldera walls about 250m-350m high. Lava flows cover much of the caldera floor and two spatter cones are present on the western and southeastern flanks of the central cone. Historical eruptions of Barren Island was recorded in 1787, 1789, 1795, 1803, 1832, 1991, 1994-1995, and more recently in 2005-2007, 2008-2010, and 2010-2011. Lava flows were often emitted as often as ash plumes during an eruption and in some cases had reached the sea. The 1991 eruption caused the partial collapse of the central cone reducing it's height from 305m to 225m and an eruption in 2005 produced 300m high lava fountains. Life on the island consists of feral goats and rats, and thick vegetation is found mainly on the outer caldera wall. Two freshwater springs was discovered in the southeastern part of the caldera.

Diagram of Barren Island. IMAGE SOURCE: Oregon State University

Aerial view of Barren Island in eruption. PHOTO SOURCE: Indian Coast Guard/Global Volcanism Program

Central cone on Barren Island. PHOTO SOURCE: bentjh/Panoramio

Info source:

Myself

Oregon State University - http://volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/india/deccan.html

Wikipedia - http://en.wikipedia.org/wiki/Narcondum

Wikipedia - http://en.wikipedia.org/wiki/Deccan_Traps

Global Volcanism Program - http://volcano.si.edu/world/volcano.cfm?vnum=0600-01=

Global Volcanism Program - http://volcano.si.edu/world/volcano.cfm?vnum=0600-001

Global Volcanism Program - http://volcano.si.edu/world/volcano.cfm?vnum=0305-01=

Department of Earth Sciences/IIT Bombay - http://www.geos.iitb.ac.in/dchandra/biexp/barrendetailed.html