Tag Archives: Hotspot

Recent Rumberlings

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Again I must apologise for a lack of posts although there has been a lot occurring in the past few weeks. Sadly life as an Open University student (something I will be writing on shortly), working full-time and having a rather active 7-year-old means my little old website tends to get forgotten about. But enough of my belly aching here of some of the world-wide volcanic updates for the month of May.

Shindake 

Friday at 9.59 am local time Mount Shindake on the island of Kuchinoerabu erupted with little warning. The plume scaled over 9 km high and a pyroclastic flow reached as far as the shore. The alert level was rasied to 5 and all 141 people on the island have been evacuated to neighbouring Yakushima island or the mainland and no one has been reported to have been hurt. It is thought that further explosions or more pyroclastic flows are likely as this volcano rarely produces one-off events. When Shindake erupted on August 3rd last year activity lasted for several days.

Telica

Sods law, I was in Nicaragua only a few months ago and all was relatively quiet. Now both Telica, north of the city of Leon and Concepción on the island of Ometepe have seen small eruptions in the past few weeks. Telica, the more active of the two, hit headlines on May 11th when a group of hikers filmed a small eruption at the summit. The night before a loud explosion was heard but not ash could be seen and it was still deemed safe for people to climb its flanks the next day. I will be honest the video which emerged did annoy me slightly as it is very indicative of todays society; of course when some thing explodes one does not think of their own safety, oh no we get our cameras out and film!

It produced about 50 small explosions within the next week or so before several days of apparent calm. It came back to life again on May 27th with a slightly larger eruption which created an ash column just over 3 km high. It is not thought that these explosions are an indication of movement of magma, rather phreatic eruptions.

Concepción on the other hand experienced about 60 small explosions on May 8th and several small earthquakes nearby. No ash was record although high gas emissions were recorded. By May 24th there had been 947 small explosions near the summit.

Wolf

Isle Isabella, the Galápagos’ largest island, is also home to its most active volcanoes. Last week Volcan Wolf began erupting with lava flows on its south eatern flank and producing an eruption column almost 15 km high according to the Washington VAAC. Satellite monitoring indicates that to plume is sulphur dioxide rich with little ash, with up to 200 kt of sulphur dioxide being emitted during the first 13hrs of the eruption alone.  Media coverage of the eruption has been higher than usual seeing as little threat is posed to the human residants, however the Galapagos islands are rich in wild life found no were else on Earth are being threatened by the situation. 

Piton de la Fournaise

A eruption began on May 17th and continued through to May 26th at Piton de la Fournaise, Reunion Island’s most active volcano. Activity and output has decreased on a whole however shows little sign of ending. 

Calbuco

The alert remains at orange for Calbuco although activity is lower than in recent weeks. Incandescence has still be osbsvered at the crater up until the night of the 26th and small gas and ash plumes tend to be about 300 m abover the summit. 6,685 people are still displaced by the 20 km exclusion zone which remains in place.
Figure 1; Shindake http://beforeitsnews.com/environment/2015/05/mount-shindake-volcano-eruption-2015-japan-issues-highest-alert-2529958.html

Figure 2; Telica http://www.stuff.co.nz/world/68521780/nicaraguas-telica-volcano-roars-to-life-spewing-ash-gas

Eruption Update

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I may have bee quiet on eruption updates lately but that is far from meaning our restless Earth has been quiet. Here is some of the recent updates.

Kilauea 

As Kilauea has been in a constant state of eruption since 1983, some don’t consider changes in activity as news. However as the June 27th lava showed us this relatively calm giant still poses a threat to people.

USGS reports suggest that the summit is still inflating; 7.5 microradians were recorded in the past week alone. Over the weekend we saw rapid filling of the Halema’uma’u crater from a depth of 90 ft from the crater rim to within 10 ft by Sunday lunch time. Yesterday (April 29th) the webcam observed small explosions and spattering with rock falls as the crater began to overflow.

Seismicity remains at an increased level towards the summit and East rift zone where wide spread breakouts from the eruption site are active as close as 8 km of Pu’u ‘O’o. There has be net inflation of Pu’u ‘O’o over the past week but not as significant as at the summit. As the June 27th Lava flows nears its 1 year anniversary incandesance indicates that surface flows remain active northeast of Pu’u ‘O’o.

Calbuco

Although the more explosive phase of the eruption seems to have died down, there are still high ash emissions and flight disruption is still an issue across both Chile and Argintina with ash plumes trailing to the north and south east at just over 1.5 km high. The 20 km exclusion zone is still inplace however it is belived that some people have returned to their homes within the area with maximum displaced 6,514 at the begining of this week. Seismicity has since declinded but it is still under observation.

Sinabung

Collapse of the lava dome on April 28th caused a pyroclastic flow to surge down the flanks. Luckily exclusion zones are still in place from activity over the past few months. The Darwin VAAC  said an ash columb exceeds 14,000 ft although satalitte confirmation has not been possible due to cloud coverage.

Aira

JMA reported that 29 explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m during 20-24 April. Nine of the explosions generated ash plumes that rose 3 km above the crater rim; one explosion, on 24 April, produced an ash plume that rose 4 km. Incandescence from the crater was visible on one night. The Alert Level remained at 3 (on a scale of 1-5). Based on JMA notices, the Tokyo VAAC reported that explosions during 22-28 April generated plumes which rose to altitudes of 1.5-4.9 km and drifted S, SE, E, NE, and N.

Tungurahua

Moderate-to-high seismic activity at Tungurahua during 22-28 April, characterized by long-period events, tremor, and explosions. On 28 April an emission with a minor ash content rose 3 km and drifted W. Roaring was noted and lahars descended the La Pampa (NW) and Rea drainages.

Popocatepetl

During 22-28 April the seismic network at Popocatépetl recorded 25-91 daily emissions mostly consisting of water vapor and gas. Cloud cover sometimes prevented observations of the crater, although gas plumes and nighttime crater incandescence were noted daily. On 22 April an explosion at 01.21 produced diffuse gas and water vapor emissions. Explosions at 16.43 and 17.58 local time generated ash plumes. The Alert Level remained at Yellow, Phase Two.

Krakatoa

PVMBG reported that during 1 March-21 April diffuse white plumes rose 25-50 m above Anak Krakatau, although foggy weather often prevented observations. Seismicity continued to be dominated by shallow and deep volcanic earthquakes, as well as signals indicating emissions. The Alert Level remained at .

Sheveluch

During 17-24 April the lava dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot block avalanches, and fumerolic activity. A thermal anomaly was detected during 16-18 and 23 April; cloud cover obscured views on the other days. The aviation code remained at Orange.

Figure 1; http://fineartamerica.com/featured/halemaumau-by-moonlight-grant-kaye.html

Figure 2; http://news.yahoo.com/image-asia-pyroclastic-flows-erupt-mount-sinabung-121702289.html

OUGS Talk; John Murray on Etna

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One of the perks of studying geoscience with the Open University is it has a very active Geological Society. Although I joined and went to the odd talk towards the start of my degree, as with many other things, life gets in the way. When I heard the speaker of April’s meeting though it was impossible to not jump at the chance to go….

Figure 1. Mount Etna with the city of Catania in the foreground

On my trip to Masaya back in February I had the privilege of working with John Murray, Visiting Research Fellow at the Open University. A geophysicist, he has worked predominantly on Mount Etna for over forty years. In that time monitoring techniques have moved on greatly, as has much else with the development of technology. This however does not mean proven techniques are not equally, and in some cases, more effective than the new. John specialises in leveling, dry tilt and more recently GPS monitoring of Etna which gives us high precision ground deformation data. For years John secured funding from NERC and many other sources to map the volcanoes deformation. In later years research has become self funded such is his drive to discover the inner workings of the Mediterranean giant.

Figure 2. A map showing the volcanoes of Italy. Etna is the only one laying of the island of Sicily.

Figure 3. John levelling on Masaya.

The other night John addressed the London branch of the Open University Geological Society (LOUGS), to tell them about his work and what he believes 45 years worth of data suggests.

Etna began to erupt roughly 300,000 years at the Val Calanna centre south-west of current activity. Subsequent activity moved on to theTrifoglietto 1 and the Trifoglietto 2 centres before its current position about 170,000 years ago which is sometimes refered to as Mongibello as depicted in figure 4.

Figure 4. Proposed migration Etna based on previous volcanic centers

The Valle Del Bovo is a prominent feature on Etna. The U-shaped depression many believe depict structural failures of the flank along the line of migration of volcanic centres. What John has suggested based on his high precision mapping is that it is not the magma source that is moving but the topography which is slipping seaward.

Also as ground deformation does not following Mogi models (a mathematical model which links changes within a magma chamber to topographical changes), it is being suggested that Etna does not have an appreciable magma chamber, rather taking its material straight from the mantle like a hot spot. This idea is chemically supported by the fact the main igneous rock produced by Etna is Hawaiite; which is compositionally similar to mantle rock.

John is yet to publish his findings in full so I won’t give away any more. It’s safe to say though it is sure to change our views of Etna’s dynamics. John’s passion in his quest to uncover Etna’s secrets is truly inspirational, especially to an aspiring volcanologist like myself. I can’t wait to work on her flanks with him next August.

Figure 5. Eruption February 23rd 2013.

Figure 1; http://en.wikipedia.org/wiki/Mount_Etna

Figure 2; http://www.understandingitaly.com/profile-content/volcanoes.html

Figure 3; Authors own.

Figure 4; http://astrolabio.amicidellaterra.it/node/329

Figure 5; http://mountetnamaddison.weebly.com/eruptions.html

Current Volcanic Activity; New and Updates.

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Sinabung

Just moments after posting this originally images came through of a pyroclastic flow at Sinabung at 14.05 GMT.
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Fogo

Finally I have found a half decent update from the Global Volcanism Program albeit for about a week or two ago. By the 6th January the lava front had stalled in areas near S Ilheu de Losna where as was still advancing at a slow rate in the northern end of the town. Houses are still being overtake by the flow but decreasing temperatures of the lava means we could be nearing an end to the destruction. For the first few days of the month sulfur dioxide emissions were averaging at 1200 to 1300 tonnes a day.

Etna

Etna saw out 2014 with some pretty explosive activity on the 29th December. The new southeast crater had consistent but small emissions and incandescents. Explosions intensified on the 2nd and 3rd sending material 150 meters above the crater rim and an ash plume which traveled southwest.

Activity has been pretty on going since December 28th and shows little sign of slowing. On January 1st and 2nd, strombolian activity was seen at th Voragine crater, which has been inactive for over two years.

HungaTonga-HungaHa’apai

Based on pilot observations an ash plume rose to just over 10,000 ft on January 6th.  This is the first notable activity at the volcano since 2009. The main caldera is submarine.

Soputan

Darwin VAAC reported that a ‘significant’ eruption began at 14.47 local time on January 6th.  A lava flow has travelled 2 km down the WSW flank although no warnings have been issued. An ash plume rose to roughly 27,000 ft how ever nothing can be detected on satellite imagery due to poor weather conditions. The alert remains at 3 on the four point scale.

Bárðarbunga

As of January 5th the lava flow now covers an area just over 83 square kilometers. although the overall intensity of both flow and seismicity is less then a few months ago, the fissure eruption shows no sign that it is coming to an end.

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Tangkubanparahu

On December 31st the alert d 2 and local residents were warned not to go within a 1.5 km radius of the crater. White plumes has been drifting from the Ratu crater since late November, but an increase in seismicity and ground deformation has led to the apparent rise in threat.

Sheveluch

KVERT reported a lot of strong activity at Sheveluch towards the end of December including incandescent avalanches and fumerolic activity. The aviation code was kept at orange as an ash plume travelled both 60 km westwards and over 370 km ENE. Satellite images indicate a thermal anomaly over a new lava dome on the northern flank.

Fogo

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As promised, this is a current catastrophe warrants its own post, especially as most of the world does not see it news worthy.

The islands of Cape Verde have become a popular destination for tourists off the coast of Africa. Their origins are volcanic;  as the African Plate moves across a hot spot. Although few of the volcanoes are believed to  extinct the island of Fogo which is thought to sit directly above mantle is rather active.

On November 23rd Pico de Fogo rumbled life again after laying in quiet almost 20 years. In an eruption true to typical hotspot volcanism, there were no huge blasts or billowing ash clouds sent rocketing in to the stratosphere, what there was was lava, volumes and volumes of basaltic lava. Moving at average speeds of just 10 m/ph basaltic lava is easily outrun and the villages like Portela and Bangueira were able to evacuate meaning little threat to human life. Does this therefore follow that there was no threat at all?

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A month on the flow still advances completely devouring the towns of Cha das Caldeiras and Portela. Homes, schoools, businesses completely gone with former residents left helpless on the sidelines. Buildings in Bangueira are also being destroyed and the lava is heading towards other villages.

View image on Twitter

Yet what makes this situation worse is the lack of world support or even knowledge of the unfolding situation in Fogo. Sorry but to me peoples homes being destroyed, livelihoods lost is a big deal. Sadly Kim Kardashian’s naked backside seems to have more media interest than the poor people of Cape Verde.

I have mentioned on several posts that world ignorance to geological events is unbelievable. But what actually makes such news relevant to world media or aid?

Fellow member of the Open University community has a similar view and wrote as such for Science2o. “Does Ebola on mainland Africa and a typhoon in the Philippines mean that there really is no time for an event such as this in our mainstream news agenda? Or do we care about volcanoes only if there’s a chance of them inconveniencing our air-travel plans?”

I wonder how quickly this may change if people understood Fogo’s past and the danger that lays beneath the lava…..

The eastern flank of Fogo is scared from a collapse caused by an eruption around 40,000 years ago. The mass of rock, debris and volcanic material crashed in to the ocean causing a mega tsunami that make 2011’s Sendai disaster look like ripples in a puddle. On the neighboring island of Santiago, evidence of the catastrophic wave can be found over 100 m above sea level. It would of swept far inland on the west coast of Africa and decimated the coasts of Portugal and Spain.

The flanks of Fogo today are still not considered the most stable although it is thought we should not see another collapse in quiet some time, pending on future eruption styles. But the idea that this small volcano, which is currently seen as insignificant to the media, could threaten people on a global scale says so much about peoples ignorance to the planet we live on.

 

Rothery, D. http://www.science20.com/the_conversation/cape_verde_volcano_the_biggest_natural_disaster_you_arent_reading_about-150923