El Hierro Overview

The 2011 submarine volcanic eruption in El Hierro (Canary Islands), Spain – Eruption overview

Last update: May 18, 2012 at 6:19 pm by By 

With special thanks to Dr. Carracedo (Geovol) allowing us to publish his report and Joke Volta for facilitating.

Dr. Juan Carlos Carracedo Gómez – ULPGC

Forty years after the Teneguía Volcano (La Palma, 1971), a submarine eruption took place off the town of La Restinga, south of El Hierro, the smallest and youngest island of the Canarian Archipelago. Precursors allowed an early detection of the event and its approximate location, suggesting it was submarine. Uncertainties derived from insufficient scientific information available to the authorities during the eruption, leading to disproportionate civil protection measures, which had an impact on the island’s economy based primarily on tourism, while residents experienced extra fear and distress.

El Hierro, 1.12 million years old, is the youngest of the Canary Islands. Located at the western end of the archipelago together with the neighboring island of La Palma, El Hierro rests on a ca. 3500 m-deep ocean bed.
The principal configuration of El Hierro is controlled by a three-armed rift zone system that gives rise to three ridges that extend from the center of the island in a characteristic ‘Mercedes star’ geometry(Carracedo, 1994), and host the larger part of El Hierro’s subaerial eruptions (Fig. 1A).
This triple-armed shape of El Hierro is further enhanced by the scars of several massive gravitational landslides that truncate all three flanks. The collapse of the north flank, that formed the spectacular El Golfo bay with an almost vertical 1400 m-high escarpment, is the youngest landslide of the entire Canary Archipelago with an age of less than 100 ka. Rift zones, however, also continue underneath the sea surface. The south rift stretches as a submarine ridge for more than 40 km (Fig. 1B), indicating that recent submarine eruptions have occurred there as well.

Fig. 1. A. Geological map of El Hierro (from Carracedo et al., 2001). B. colour shaded relief image of El Hierro viewed from above (from Masson et al., 2002). The subaerial and submarine parts of the South rift are indicated.

During the German research cruise Meteor 43/1 in 1998, lava samples were dredged from the submarine prolongations of the southern rift zones of La Palma and El Hierro. El Hierro samples taken close to the present eruptive site (<3 km distant) included fresh picrites and alkali-basalts and variably altered lapillistones and hyaloclastites. Further dredging along the submarine north-west and north-east rift zones during the Poseidon 270 cruise in 2001 recovered fresh alkali basalts from 21 young volcanic cones at depths of 800 to 2300 m together with ocean bottom sediments having a strong volcaniclastic component.
It appears overall that the density of seemingly young volcanoes on El Hierro’s submarine rifts is comparable to that on land, emphasizing the relevance of submarine eruptions during the growth of oceanic islands.

Precursors to the 2011 eruption

Numerous earthquakes were recorded by the Spanish Instituto Geográfico Nacional (IGN) from July 2011 onwards, the greater part of them insignificant from a hazard point of view, but were clearly precursors of a volcanic eruption. In particular, seismicity, initially of low magnitude (M < 3.0) and focused north of the island, increased while migrating southward. The greater part of the hypocentres were initially concentrated within the lower oceanic crust (Fig. 2), at depths of 8–14 km (ca. 200–400 MPa pressure), which is in agreement with pressure estimates from microscopic fluid inclusions in xenoliths from north-western El Hierro and phenocrysts from a recent eruption. The seismic and petrological data are thus in-line with a scenario of a magma batch becoming trapped as an intrusion horizon, near the base or within the subisland oceanic crust. Shifting seismic foci suggest that magma progressively accumulated and expanded laterally in a southward direction, causing a vertical surface deformation of about 40 mm at that time.
During this initial phase, the system remained active but showed no sign of having overcome the resistance of the oceanic crust. Hypocenters thereafter migrated south-east, approaching the submarine prolongation of the active South rift zone. From there, the magma progressed rapidly towards the surface, as indicated by the first time occurrence of shallow (< 3 km) earthquakes on 9 October 2011.
The scenario changed dramatically at about 4 am on 10 October, when the now frequent and strong seismicity (up to M 4.4) ceased and was rather abruptly replaced by a continuous harmonic tremor, indicating the opening of a vent and thus the onset of a submarine eruption.

Fig. 2. Seismic hypocentres beneath El Hierro between 19 July and 10 October 2011. Hypocentres migrated from North towards the South rift zone of the island, where they became shallower (< 3 km). The eruption commenced on 10 October. Most of the time, seismicity remained stable at the base of the oceanic crust (data from IGN, http://www.ign.es/ign/resources/ volcanologia/ html/eventosHierro. html)

The submarine eruption

On October 10, patches of pale-colored water that smelled of sulfur and were associated with dead fish, were found floating one mile south of the coast confirming the opening of a vent on the flank of the submarine part of the South rift zone. The surface expression of this eruption, including green and bright discoloration of seawater, was clearly observed in high-resolution satellite images featuring a large stain(locally known as ‘la mancha’) visible on the surface of the Las Calmas Sea (Fig. 3A). The eruption formed aNE–SW trending fissure outlined by strong bubbling and degassing (Fig. 3B), occasionally 10–15 m high, loaded with juvenile volcanic ash and pyroclasts (Fig. 3C).
However, information on the depth and precise location of the submarine vent was lacking in the first two weeks of the eruption because of the unavailability of adequate means for submarine surveying.
On October 24, the RV Ramón Margalef of the Instituto Español de Oceanografía (IEO) carried out the first survey of the area, previously mapped in 1998 by the Spanish RV Hespérides (Fig. 4A). Comparison of present and 1998 bathymetry outlined a 700 m-wide, 100 m-high new volcanic cone resting at about 350 m depth in a canyon on the flank of the South Rift submarine extension (Fig. 4B). On 4 December 2011, the eruption apparently waning, the RV Ramón Margalef carried out another campaign, detecting significant growth of the volcanic edifice. The initial single eruptive center (Fig. 4A,B) had now evolved to three cones of similar height, with their summit 180–160 m below the sea surface (Fig. 4D), still below the critical value to generate significant surtseyan explosions (about 100 m below sea level).
Lava flows and pyroclasts, confined by the canyon walls, caused the greater part of the erupted volume to flow downslope towards deeper parts of the ocean floor.

Fig. 3. A. Plume of dissolved magmatic gases and suspended matter producing green and bright discolouration of seawater (locally known as ‘la mancha’) commencing on 10 October 2011 and continuing for several kilometres to the south-west before drifting off into the Atlantic (Satellite image by RapidEye). Fig. 3. B. Plumes of gas on ocean surface showing a N–S trend, indicating a submarine eruptive fissure. Inset: Expansion of steam with decreasing water depth (modified from Schmincke, 2004). C, strong degassing with abundant rock fragments generated large ‘bubbles’, some of them 10–15 m-high, bursting to the surface off the nearby village of La Restinga (8 November 2011).

 

Fig. 4. A. DEM showing the pre-eruptive submarine canyon where the 2011 eruption nested (image taken from the RV Hespérides, 1998). B. DEM of the same area taken on 24 October by the RV Ramon Margalef after the onset of underwater activity. C. Geological map of the submarine eruption from the first DEM obtained on 24 October 2011 by the RV Ramon Margalef. D. Geological map of the same area on 4 December 2011.

Floating stones off El Hierro

Abundant rock fragments resembling lava bombs on a decimeter scale (Fig. 5) and characterized by glassy basaltic crusts and white to cream-colored interiors, were found floating on the ocean surface during the first days of the eruption. The interiors of these floating rocks are glassy and vesicular (similar to pumice), with frequent mingling between the pumicelike interior and the enveloping basaltic magma (Fig. 5B).These floating rocks have become known locally as ‘restingolites’ after the nearby village of La Restinga. Their nature and origin remained elusive at first, with suggestions from the scientific community including: (1) the floating bombs are juvenile and potentially explosive high-silica magma; (2) they are fragments of marine sediment from the submarine flank of El Hierro; and (3) that they are relatively old, hydrated volcanic material. However, none of these interpretations provides a satisfying fit to the available observation since for instance, high-silica volcanism is uncommon on El Hierro, and magmatic minerals (either grown in magma or as detritus from erosion) are entirely absent in the ‘restingolites’. Given that the involvement of highly evolved, high-silica magmatism would have implications for the explosive potential of the eruption, it was important to clarify the nature of the ‘restingolites’ swiftly in order to fully assess the hazards associated with the ongoing El Hierro eruption. Furthermore, should the ‘restingolites’ be shown not to originate from high-silica magma, then unraveling their genesis will most likely provide unique insights into the volcano–magma system beneath El Hierro.
All ‘restingolite’ samples are glassy and light in color and most are macroscopically crystal-free. However, occasional quartz crystals, jasper fragments, gypsum aggregates and carbonate relicts have been identified in hand specimens. X-Ray diffractograms mainly indicate the presence of quartz, mica and/or illite, and glass. There is a notable absence of primary igneous minerals from the XRD data. Microscopic quartz crystals have also been identified and analysed using a field emission electron probe micro-analyser (FE-EPMA), as well as the composition of the glass matrix, which ranges between ~65 and 90 per cent SiO2.
The high silica content coupled with overall low incompatible trace element concentrations, the occurrence of mm-sized relict quartz crystals and the lack of igneous minerals, plus the occurrence of carbonate, clay, jasper and gypsum relicts are all  ncompatible with a purely igneous origin for the cores of the floating stones. Igneous rocks on El Hierro do not contain any free (primary) quartz crystals (nor do igneous rocks on any of the other Canary Islands).
A potential source of the quartz crystals found in the floating rocks from El Hierro is likely to be the sediments of layer 1 of the pre-island ocean crust. These contain quartz crystals transported from Africa by both wind and turbidity currents and are characterized by a lack of igneous minerals due to their pre-island age.

Fig. 5. A. ‘floating rocks’ observed in October 2011 off El Hierro. B. ‘restingolite’ sample displaying typical features, such as a crust of basalt, primary sedimentary bedding, folding, high vesicularity, and mingling structures. C. hollow basaltic bomb of the late stages of the eruption. D. similar bomb from the Serreta Oceanic Volcano, Terceira, Azores (photograph by Ulrich Küppers).

The floating rocks found at El Hierro are thus most probably the products of magma–sediment interaction beneath the volcano (Fig. 6). Ascending magma mixes with the pre-volcanic sediments and the ‘restingolites’ were carried to the ocean floor during eruption while being melted and vesiculated during transport in magma. Once erupted onto the ocean floor, some of them were able to separate from the erupting lava and floated to the sea surface due to their low density (Fig. 6).

for more information and updates, go to:    http://earthquake-report.com/2012/05/18/the-2011-submarine-volcanic-eruption-in-el-hierro-canary-islands-spain-eruption-overview/

Nevado fel Ruiz Volcano Nearing Eruption?

Nevado del Ruiz in Colombia May Erupt in “Days to Weeks”

The small steam plume from Nevado del Ruiz, seen on March 27, 2012. Image from INGEOMINAS Colombia.

Some news brought to my attention by Eruptions reader Sherine merited a quick Saturday post. Thedeveloping volcanic crisis at Nevado del Ruiz in Colombia looks like it is continuing to escalate. INGEOMINAS, the Colombian geological survey, released a “special bulletin” this afternoon elevating the alert status at Nevado del Ruiz to Orange Level (II). This means that the signs of activity at the volcano suggest that an eruption is likely in the days to weeks timescale. Marta Calvache from INGEOMINASmentioed that over the past few days the volcano has experienced tremor related to “fluid motion” (likely magma), rock fracture earthquakes at the summit have been increasing in pulses and sulfur dioxide emissions continue to be high.

 

So far, INGEOMINAS thinks any potentially eruption will be smaller than the activity seen during Ruiz’slast eruptive period between 1985-1989. The major hazard from Ruiz is the lahars that can be generatedas ash and other volcanic material mix with melted snow and ice at the summit. There is also the potential for ash fall (especially hazardous for those with respiratory problems) on towns and cities in the area, including Manizalez and Pereira, both of which are less than 50 km from the volcano, and Bogotá, only ~120 km from Ruiz. If you live in the area around Ruiz, be sure to examine the INGEOMINAS volcanic hazard map to see the places with the highest probability of lahars and pyroclastic flows. Taking a look at the INGEOMINAS Azufrado webcam for Ruiz, a plume can be seen coming from the summit area (see below) while the webicorder shows the increasing seismicity as well. You can also get a glimpse of the volcano from an INGEOMINAS webcam in Manizalez.

Webcam capture from March 31, 2012 showing a small plume from Nevado del Ruiz in Colombia.

from:    http://www.wired.com/wiredscience/2012/03/nevado-del-ruiz-in-colombia-may-erupt-in-days-to-weeks/

 

Signs of Volcanic Unrest on Santorini

Scenic Greek Island Shows Signs of Volcanic Unrest

Stephanie Pappas, LiveScience Senior Writer
Date: 13 March 2012 Time: 02:59 PM ET
Buildings crowd a steep oceanside cliff on Santorini.
The crowded cliffsides of Santorini island in Greece.
CREDIT: MaugliShutterstock

The volcanic caldera on the picturesque tourist island of Santorini is showing signs of unrest. But researchers detecting the caldera’s movement say it doesn’t necessarily mean an eruption is imminent.

The Greek island was the site of one of the most massive volcanic eruptions in history 3,600 years ago. That eruption, which created tsunamis 40 feet (12 meters) tall, may have spawned thelegend of the lost city of Atlantis. The volcano last erupted in 1950, albeit on a much smaller scale.

Global positioning system (GPS) sensors placed on the caldera have detected renewed movement after decades of peace. The earth around the caldera (a depression at the top of a volcano) is deforming, or expanding outward, researchers report in an upcoming article in the journal Geophysical Research Letters. GPS instruments on the northern part of Santorini have moved between 1.9 and 3.5 inches (5 to 9 centimeters) since January 2011, said study researcher Andrew Newman, a geophysicist at Georgia Tech in Atlanta.

“What we’re seeing now is the first significant deformation and the first deformation that has any significant earthquake activity associated with it,” Newman told LiveScience.

In the same time period, the magma chamber under Santorini has swollen by almost 500 million cubic feet (14 million cubic meters).

Newman and his colleagues say it’s unlikely that the deforming caldera portends an eruption. Excavations of extinct volcanoes suggest that 90 percent of the time, belowground magma movements don’t end in eruption. A similar caldera system, the Long Valley Caldera in California, started deforming in 1980, Newman said. It then quieted again until 1989, repeating the cycle in 1997 and 2002, with nary an eruption.

If a Santorini eruption did occur, Newman said, it would be nothing like the Minoan eruption of 1650 B.C. that birthed the myth of Atlantis. That eruption was a once-in-100,000-year event, and the expansion of the magma chamber happening now is only 1 percent of what would have gone on prior to the ancient blast. [The 10 Biggest Eruptions in History]

Geophysicists are keeping an eye on the caldera, however. An eruption could generate local tsunamis within the Santorini archipelago, Newman said, damaging ports and disrupting ship traffic. Even if the volcano doesn’t erupt, the shifting caldera could increase earthquake risk, and the island cliffs are vulnerable.

“We don’t need an eruption to have earthquake-induced landslides,” Newman said.

There’s no telling how long the deformation will continue, but it could stretch years or decades, perhaps cycling between activity and peace, Newman said. While no reason to be alarmed, the restless caldera is important for scientific study, he added.

“It is one of very few of these really large caldera volcanoes,” he said. “So any information we gather from ongoing activity adds significantly to our database of how these systems evolve.”

from:    http://www.livescience.com/19018-santorini-greek-volcanic-unrest.html

El Hierro Update

El Hierro Volcano : Yellow alert – Images of Glowing Lava at 70 meter depth

Last update: March 19, 2012 at 6:41 pm by By 

VERY IMPORTANT Update 19/03 – 17:02 UTC
– ER reader Roland (see comments) has given us the lead to a report of the University of Las Palmas de Gran Canaria showing the still erupting submarine El Hierro volcano with glowing lava seen floating at a depth of 70 meter.
What nobody could accomplish so far, has been done by the ROV E-Wally on board of the SOS-OceanosQ-StarAtlantic Explorer ship by the scientists of the Universidad de Las Palmas the Gran Canaria.
– The images have been captured on March 14 as the date on the images reveal. The images are of course foggy as a lot of suspended material is polluting the water.
– No doubt that Q-Star and the University has also some video footage that they will probably release later on (the pictures are probably screen captures of the video).
We are however VERY PLEASED that all those who cooperated on this mission have proved that the eruptive process is not yet entirely finished (at least it was not after the date that Pevolca said that the eruption stopped).

Original images courtesy Q-Star and Universidad de Las Palmas de Gran Canaria

ER manipulation of the color saturation and contrast from the original picture above, a lot more details are appearing

 

Image Courtesy Q-Star and Universidad de Las Palmas de Gran Canaria

Update 19/03 – 16:00 UTC
– Images of Joke Volta of today March 19

Update 19/03 – 11:17 UTC
– Nothing unusual this morning.
– Since midnight NO listed earthquakes since Saturday
– Sunday afternoon we noticed increased microseismicity. The variation in HT signal is often caused by changes in tide, wind, waves etc, external factors which have nothing linked to the eruption. However, a minimal HT is still present.
– Joke continues taking her daily pictures, with of course more focus to the island itself these days. She does not want to give up right now as the eruption might get stronger again.

for more information and updates, go to:    http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/

El Hierro Update

El Hierro Volcano : Yellow alert – Atlantic Explorer will try to use the ROV on Tuesday

Last update: March 12, 2012 at 3:19 pm by By 


Update 12/03 – 07:28
– The Atlantic Explorer vessel of the company QSTAR SLU, hired by members of ‘Universidad de las Palmas de Gran Canaria’ (ULPGC) and collaborating, the non-profit organisation, SOS Océanos is back in town. Julio received an Email from one of the people in charge that they will try to use the ROV today on Tuesday, weather permitting of course.
– 2 earthquakes so far today – M &.1 and M 1.3 both at a depth of 12 km


Update 11/03 – 23:55
– New images from Joke Volta have been loaded in our picasaweb
– A 5th earthquake with a magnitude of 0.6 occurred at 21:37

Update 11/03 – 22:58
– no more new earthquakes
– some people are looking for a new name for the new volcano. IGN scientists are talking internally about “El Volcan de La Restinga”  but a new name is certainly desirable.
– Involcan and ITER have published the new CO2 graphs who are showing a light increase to 934 ton per day.

Update 11/03 – 21:34 UTC
– Today a number of people and Joke saw a faint jacuzzi or rather degassing in the vent area. This was also confirmed by scientists.
– The degassing started already yesterday afternoon and was mentioned by some ER readers, Julio and AVCAN.
– We think it is probably too early to talk about a reactivation of the eruptive process.

Update 11/03 – 18:38 UTC
– Images Joke Volta from today showing a beautiful sunrise and a few images with a super faint jacuzzi. Click here.

Update 11/03 – 08:38 UTC
– 4 earthquakes so far since midnight. Resp. 1.8, 1.5, 0.3 and 1.7. Depths in between 8 and 12 km.


Update 10/03 – 23:10 UTC
– The Atlantic Explorer vessel is currently navigating to El Hierro for a new campaign. In the team, members from the Universidad de Las Palmas de Gran Canaria and SOS Océanos. Lets hope this time the conditions will be good enough for deploying the ROV.
Update 10/03 – 21:45 UTC
– The following video shows the activity at ‘El Mar de Las Calmas’ from 18:55 to 19:55 UTC  x10 normal speed, by Julio del Castillo Vivero.

– AVCAN (Actualidad Volcánica de Canarias) believe the eruption was not over and continues.
– Joke Volta has spoken with Ramón Ortiz and here we have translate his words for what he believes could be happening:

” What can be observed now we saw 2 weeks ago. I have looked at the seismic network, and there has been no variation, no anomalies. When there is an eruptive activity this is reflected in the seismic network. What could be happening is that as magma is still hot, it takes time to cool down, this material is still releasing heat and vapor, and there is still gas release. That is why there is still an exclusion zone around the volcano. Tides can affect the process that we see. As the tide changes, the pressure does too and this can alter what is happening. The effect of the tides we have observed it two weeks ago when there was a decrease in activity. The visibility of the volcano changes and this is also due to the tides.

– What we are sure of is there has been no official communication about what is happening.

for more information and updates, go to:    http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/

Mt. Etna’s First 2012 Eruption

Mount Etna Erupts (VIDEO)

First Posted: 1/5/12 12:01 PM ET Updated: 1/5/12 12:03 PM ET

Europe’s tallest active volcano Mount Etna erupted for the first time this year.

On Wednesday night, the volcano released a column of ash, and lava was seen running down its eastern flank. The volcano is located on the island of Sicily.

According to Reuters, the eruption caused no damages or air traffic disruptions.

Check out the link below for some ectacular footage from the eruption.

from:  http://www.huffingtonpost.com/2012/01/05/mount-etna-erupts_n_1186391.html

New Island Created by Jebel Zubair Volcano

Surtseyan eruption along the coast of Yemen forms a new island – Today eruption cloud + stain !

Last update: December 30, 2011 at 3:07 pm by By

Jorgen Aabech, a Norvegian volcano enthusiast writing already a long time in his blog vulkaner.no, wrote us an email on  December 20 to attract our attention on a probably new eruption of the Jebel Zubair volcano, which is an island formation on the territory of Yemen. Jorgen asked us if we had any mention of earthquakes in the area, which was negative.
When looking at the Modis Terra and Aqua satellite picture on December 20, we saw indeed a very small cloud in the island area, but nothing important to us.  We also followed the Sat24 weather satellite pictures for a while to eventually detect heat on their Infrared images, but also this was negative.  This whole eruption, actually found by the scanning of Jorgen Aalbach (if we are right), was almost forgotten until NASA’s Earth Observatory published a far better satellite picture showing more detail of the eruption. Just like during the Eritrea Nabro eruption, satellite images are the only source in this part of the world (in other words, these countries have other concerns than following an active volcano area all the time)

Update December 30
– NASA Modis Aqua satellite picture is showing more activity today. The quality of the Satellite images differs because of indirect circumstances like high cloud, etc (visual image)

 

Update December 29 (all other info below).
– As you can see on the picture above, the eruption is still ongoing (white cloud and blue stain)
– It is a pity that nobody was around to make beautiful pictures from this Surtseyan eruption (not too late though – to all nature photographers : take your backpack and travel to Yemen (do not forget to hire some armed guards as the country has still a lot of armed rebels and as almost everyone carries a knife and a gun).

NASA MODIS Aqua December 29 satellite picture showing eruption cloud and stain – courtsey NASA

– The Yemen times, a local Yemenite newspaper (who does not mention the creation of a new island) wrote the following :
The Monitoring Center for the Study of Earthquakes and Volcanoes has reported the presence of light volcanic activity on one of the unpopulated islands of ‘Jabal Al-Zubair’ archipelago, 120 km northwest of Hodeida Governorate. Jamal Sha’alan, the manager of the center said that initial indications are that the volcanic eruption was light and will not pose a threat to marine navigation. Saleh Al-Maflahi, the assistant manager of the center, also confirmed that initial indications of the volcanic eruption are reassuring, saying that the centre has commissioned technical experts to travel to the site of the volcano to conduct studies. The team has installed a seismic monitoring station there to alert them to seismic activity that may be the precursor to volcanic activity, according to Al-Maflahi. “The volcanic activity and rising smoke was witnessed by some visitors,” he said, adding that a good deal of seismic activity had recently taken place. He said that the results of a survey of the area’s volcanic history showed that Jabal Al-Zubair is an active volcanic site, and that it witnessed volcanic activity 187 years ago. In September 2007, a volcano on Jabal Al-Tair Island – 20 km southwest of Al-Zubair and 140 kilometers off Yemen’s western coastline – caused the death of eight Yemeni soldiers in addition to injuring others stationed at a military base. Read the complete article here

Distance from the new created island to “Rugged Island”, part of the Zubair volcano group

The text below is courtesy Jorgen Aabech vulkaner.no and a few other sources which are referred to if used

December 19 – Jorgen Aabech wrote in his blog :
A possible eruption occurred at Az Zubair archipelago on 19th December 2011. Fishermen from Salif port city in the west of Yemen reported seeing an eruption with red lava rising to a height of 30 m. This was the first eruption the fisherman can recall from the area. Satellite images showed raised sulphur dioxide emissions close to the volcano on the following day.
On December 19 the NASA Aura/OMI SO² satellite captured a picture that revealed a strong SO² cloud column. This satellite is of great importance to detect remote located volcanoes.

Aura/OMI NASA SO2 satellite image from the December 19 2011 Zubair
 volcano group Surtseyan eruptionAura/OMI NASA SO2 satellite image from the December 19 2011 Zubair volcano group Surtseyan eruption

Surtseyan eruption in Yemen - Image courtesy vulkaner.noSurtseyan eruption in Yemen – Image courtesy vulkaner.no

December 20 – Jorgen Aabech Update (based on what he also read in Erik Klemetti Wired corner)
It seems like there is a lot of confusion about exactly where the eruption is taking place. A number of sources put the eruption at Jebel Zubair, another island volcano that is part of an archipelago that last erupted in 1824. Jebel Zubair is just to the south of Jebel at Tair, so looking at the OMI map and the new MODIS image found by Eruptions reader Kirby that looks to have a small plume (see above), it is more likely Jebel Zubair. However, there is still not a lot of information out there on this eruption.

December 22 – Jorgen Aabech
On 19 December a SO2 cloud was detected in an OMI satellite image. MODIS imagery from 20 December shows a plume rising from a submarine eruption about 1.5 km SW of Haycock and N of Rugged (near the N end of the Az-Zubair island group), and about 12 km NE of Jebel Zubair island.
A bathymetric sketch map made in 1973 indicates a water depth of about 100 m in that area.

Yemen TV showed an unstable and bad colored report in their news. We cannot trace whether this report is from this eruption, but it was published as it on You Tube.  It is however hard to believe that the December 19 eruption (no other SO2 traces on the satellite maps) have build the island in only a week. A possibility is that the eruption had started a lot earlier in his submarine phase.

December 28 – Smithsonian Institution Global Volcanism program writes :
An eruption from the northern part of the Zubair Group continued during 21-27 December. MODIS imagery from NASA’s satellites on 22 December showed a plume, possibly containing ash, rising from what was thought to be a submarine eruption. Imagery acquired on 23 December from the Advanced Land Imager (ALI) on NASA’s EO-1 satellite showed a new island at the location with a plume rising from it, roughly 500 m N of Rugged Island and more than 500 m in diameter. The island was not present in a similar image acquired on 24 October 2007.

December 28 – NASA Earth Observatory – Proof of a new island
The Picture combination below from NASA Earth Observatory shows the birth of the new island. The cloud picture was acquired by the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite. A thick plume rises from the island, dark near the bottom and light near the top, perhaps a mixture of volcanic ash and water vapor.

NASA Earth Observatory shows the birth of the new Zubair volcano 
group islandNASA Earth Observatory shows the birth of the new Zubair volcano group island

for more information and updates, go to:    http://earthquake-report.com/2011/12/29/surtseyan-eruption-along-the-coast-of-yemen-forms-a-new-island-today-eruption-cloud-stain/

Indonesian Gamalama Volcano Erupts

Eruption of the Gamalama volcano, Ternate, Indonesia

Last update: December 5, 2011 at 3:47 pm by By 

Panoramio picture of the Gamalama volcano, Ternate – courtesy Travel Photography

Panoramio picture of the Gamalama volcano, Ternate – courtesy Travel Photography

On December 05 at 00:08 local time, Mount Gamalama has erupted and spewed lava and ash on a town in eastern Indonesia, prompting thousands of residents to flee. A scientist monitoring the volcano, says the eruption has caused panic on the island.

Update 05/12 – 12:25 UTC
– The Indonesian authorities are maintaining the current alert level on Siaga
– The latest bulletin of VAAC (Volcanic Ash Advisory ) is mentioning the eruption but has no specific ash cloud radius due to the bad weather (cloud). VAAC says the the volcano plume rose 1500 ft above the crater (approx. 500 meter)

Update 05/12 – 11:00 UTC :  Disturbing Images of the Indonesian TV are showing people running away from there houses and ash flooding in villages. The weather is really bad in the area and actual footage of the eruption itself is not yet published.
– People are advised to wear masks as it is raining ash.
– The airport has been closed
– The volcano is in the second highest state of alert (Siaga or Level 3) since December 4, 2011
– Some people choose to evacuate to the neighboring island of Tidore
– Last eruption of the Gamalama volcano occurred in 2003

Historic eruptions of the Gamalama volcano (Gunung Gamalama)

Data from James Daniell Volcano CATDAT

for more, go to:   http://earthquake-report.com/2011/12/05/eruption-of-the-gamalama-volcano-ternate-indonesia/

Eruption -Tungurahua Volcano, Ecuador

Orange Alert after renewed eruption activity of the Tungurahua Volcano, Ecuador

Last update: December 1, 2011 at 5:06 pm by By 

Both, the Tungurahua volcano and the neighboring Sangay volcano  are belonging to the most active volcanoes of Ecuador.  Although the volcano has an almost permanent state of activity, authorities had to call an Orange alert after incandescent flows and some violent explosions.

Recent and current Activity

Tungurahua during an earlier active period – image by Armand Vervaeck taken during an earlier visit – This picture was taken from Chalet Swiss above Baños

December 1
Since this morning the intensity of emissions (gas and ash) tends to decrease, said the Geophysical Institute of Ecuador in a report.  Seismic activity associated with emanations is continuing. Ashfall and 8 minor explosions were reported in the villages surrounding the volcano. No pyroclastic flows or expulsion of incandescent rocks from the crater have been seen recently. Emergency services have told villagers to stay away from river valleys if it would be raining, as the recent pyroclastic flows can create dangerous land/mud/slides of pyroclastic material.

November 30
A total of 638 families living in three parishes in the Tungurahua volcano area received  relief by the SNGR. People living near the the volcano are used to the activity as there is always some continuing seismic activity.However, the authorities decreed on Sunday an orange alert due to the sudden increase in eruptive activity.

November 29
Various relief agencies in the province provide help to the inhabitants of Cotaló, Cusúa, Bilbao, Chacauco, Pillate and other sectors affected by the volcano into reaching evacuation trucks which will transport them to shelters in in La Paz and Riobamba.
The ‘Guadalupe’ Center which is monitoring Tungurahua reported constant explosions (windows rattled at the center)  + an ash cloud which rose to more than two kilometers.

November 28

At 02:00 on 28 November an explosion ejected incandescent material that fell on all flanks, and generated a pyroclastic flow that descended the Achupashal drainage. Starting before 0500 until 0900 an almost constant roar was heard and incandescent blocks traveled 1 km down the flanks, especially towards the W and NW.
Three pyroclastic flows were noted on the S flank.
Windows vibrated at the Tungurahua Observatory (OVT) in Guadalupe (14 km N). During the day, an ash plume rose 3 km above the crater and drifted in multiple directions. White ashfall was reported in Manzano, Choglontús (SW), Pondoa (8 km N), and Runtún (6 km NNE). In the evening incandescent blocks that were ejected 300 m above the crater rolled 400-500 m down the flanks. On 29 November an explosion detected at 0611 produced a small pyroclastic flow that traveled 500 m. Another pyroclastic flow at 0955 traveled 1 km W. Gas-and-ash plumes rose 4 km above the crater and drifted SE and W. According to a news article, people in high risk areas on the flanks, in communities such as Cusúa, Juive, Palictahua, and Manzano, evacuated voluntarily.

November 27
IG reported that increased seismicity from Tungurahua was detected at 15:40 on 27 November, and at 16:50 the seismic network recorded 4 volcano-tectonic earthquakes. Two small explosions at 17:01 and 17:05 were followed by a large explosion at 17:18.
Pyroclastic flows descended the Achupashal, Chotanpamba, and Mandur drainages on the NW and W flanks. Two more large explosions were detected at 17:31 and 17:35.
Incandescent blocks traveled 1 km down the flanks, and roaring noises and sounds resembling “cannon shots” were reported. Ashfall was reported in Manzano (8 km SW), Bilbao (8 km W), and Pillate (8 km W), ash and tephra fell in Cotaló (8 km NW), and tephra fell in Cusúa (8 km NW).
At 19:05 a pyroclastic flow descended the S and SW flanks.

Tungurahua volcano action a few years ago – picture taken by Armand Vervaeck from a cemetary at Ambato, Ecuador

Global Volcanism Program information
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.

for more, and updats, go to:    http://earthquake-report.com/2011/12/01/orange-alert-after-renewed-euption-activity-of-the-tungurahua-volcano-ecuador/

Latest on El Hierro

El Hierro Volcano (Canary Islands) : Red alert – spectacular increase of harmonic tremor

Last update: November 20, 2011 at 1:29 am by By 

Late night data update 19/11 – 23:16 UTC
– 15 M+1.5 earthquakes today
– Strongest earthquake being a 3.3 at 18:27
– Depth of the earthquakes since midnight : 16 to 23 km
– Harmonic tremor remains 
strong since 17:16 UTC tonight
– GOOD air quality all day long

 

Important update 19/11 – 17:46 UTC
– We have just noticed that the harmonic tremor is almost saturated again, the biggest change since the fallback on November 17. The second graph shows the harmonic tremor from November 17 when it collapsed, until the new saturated graph today.

Increase of harmonic tremor between 17:00 and 18:00 UTC on November 19 – image courtesy IGN

 

harmonic tremor from late November 17 until November 19 – Click on the image to see it in full size

 

Data update 19/11 – 16:37 UTC
– 10 M+1.5 earthquakes since midnight (a lot less than we have expected)
– Strongest earthquake being a 2.8 at 08:20
– Depth of the earthquakes since midnight : 16 to 23 km
– GOOD air quality values this morning

Update 19/11 – 16:37 UTC
– Ian Carson reports from El Hierro : Civil guard went out to sea in RIB (rigid inflatable) this morning. Spoke to English speaker also aboard. He said ‘volcano quiet today, stain still visible but much lighter than in past ‘Jacuzzi’ times.

for more, updates, and reports, go to:   http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/