[Vulkanen] The ring of fire #6: Waar diverse vulkanen puffen

De vorige deeltjes
• [vulkanen] The ring of Fire
• [Vulkanen] The ring of Fire #2:
• [Vulkanen] The ring of Fire #3: Eruption of Mayon?
• [Vulkanen] The ring of fire #4: Veel aktiviteit!
• [Vulkanen] The ring of fire #5: Het blijft actief

In dit en komende topics, zal informatie gegeven worden over vulkanen door enthousiaste Fokkers!, en iedereen die wat weet over vulkanisme, mag hier z'n bijdrage erbij toevoegen.

Hoofdzakelijk zijn het de aardse vulkanen in belangstelling staan. Maar als er op een andere planeet/maan vulkanische aktieviteiten Zijn, dan mag het hier ook terzake komen.

Mocht er een zeer heftige/gewelddadige uitbarsting van een vulkaan plaatsvinden komt er naast dit topic ook nog een eigen topic.

De Aarde
Er zijn bergen, eilanden, en zeeën. En alles op een laag (aardkorst) van ongeveer 35 kilometer dikte.

De aardkorst
Al miljoenen jaren is de aardkost in beweging Door zijn aardbevingen, en er zijn vulkanen laat de aarde merken dat ie nog altijd actief is. De aardkorst bestaat niet uit één groot stuk maar uit een stuk of 9 grote en nog een aantal kleinere tektonische platen. Deze platen drijven op een vloeibare mantel.

En omdat die platen niet allemaal dezelfde kant opgaan. Komt het er op de plaatsen waar ze zich ontmoeten toe tot hevige botsingen. Op deze plekken kunnen zich ook de meeste vulkanen vormen.

De bekendste term wat betreft vulkanen is toch wel de Ring of Fire. Deze 'circel' omvat zon beetje de hele StilleOceaan waar één grote aardplaat tegen diverse andere botst en rondom die plaat bevinden zich de meeste actieve, maar ook gevaarlijkste, vulkanen.

Ring of Fire


De Mantel
De aardmantel of kortweg mantel is de laag in de opbouw van de Aarde die direct onder de korst ligt. De mantel begint op enkele tientallen kilometers diepte, en is ongeveer 2900 km dik. Ze neemt 83% van het volume van de Aarde in en bevat 67,5 % van haar massa.



Soorten vulkanen
Er zijn 6 verschillende soorten vulkanen.

• De spleetvulkaan
Een lange scheur in de aardkorst waardoor magma naar buiten komt. Deze ontstaat als twee tektonische platen uit elkaar drijven. Je vindt deze vooral bij oceaanruggen.

• De schildvulkaan
Dit is een brede, ondiepe vulkaankegel, die ontstaat doordat het lava dat eruit stroomt, dun en heet is en heel langzaam afkoelt.

• De koepelvulkaan
Deze kent een steile, bolle helling die gevormd is door dikke snel afkoelende lava.

• De slakkenkegel
Een vulkaan die naast lava ook veel as uitspuugt. De berg die door deze vulkaan gevormd wordt, is dan ook opgebouwd uit lagen as en lava die elkaar afwisselen.

• De samengestelde vulkaan
Deze is net zo opgebouwd als de slakkenkegel maar heeft naast de hoofdkrater nog meerdere kleinere kraters op haar flanken.

• De calderavulkaan
Dit is een oudere vulkaan met aan de bovenkant een grote brede krater. In deze krater hebben zich weer kleinere nieuwe kraters gevormd.

• Hotspots
Doordat een zeer hete brandhaard (hot-spot) in de mantel, door de aardkorst heen brandt.

Andere vormen van vulkanisme zijn de geisers en de hete bronnen. Die vind je vaak in de buurt van vulkanen waar de aardkorst dunner is en de warmte van het magma verder doordringt in de aardkorst. Een geiser is een holte in de aardkorst of een waterhoudende grondlaag, die door het onderliggende magma wordt verwarmd tot het kookpunt. Het water kan dan tot 500 meter in de lucht spuiten. Een hete bron werkt op dezelfde manier alleen wordt het water daar niet zo verhit, dat het onder druk van stoom eruit spuit.

Heeft Nederland een vulkaan?
Jazeker! De naam ervan is Zuidwalvulkaan, en ligt 17km ten westen van Harlingen
maar ... die is letterlijk allang dood en begraven. Deze ligt namelijk vele honderden meters onder de bodem van de huidige Waddenzee.

Links
• Status vulkanen Indonesie *NEW*
• Volcano webcams all over the world
• BBC-How volcanoes work
• (Nieuws-)Updates van Vulkaanjager Jon Seach
• Global Volcanism Program
• Volcano Discovery
• Live Science - Volcanoes
• 37 Volcano Cams
• Vulkanen.nl
• Mediatheek - Vulkanen
• vulkaan.startpagina.nl
• Kennislink (Zuidwal vulkaan)
• Vulkanen in de Eifel (Duitsland)
• Planet-wissen [vulkanen](Duitstalig)

Foto's
• Meest spectaculaire vulkaanuitbarstingen op foto

Verwante (aktuele) WKN-vulkaantopics
• Uitbarsting El Hierro Canarische Eilanden
• Vulkaanuitbarsting Chili
• Tungaruhua Ecuador
• Vulkanen IJsland #18
• De Riftvallei, Nieuwe oceaan kan Afrika in tweeën splitsen

Archief en Verzamel topics
• Krakatoa
• Etna
• Supervulkaan Yellowstone #2
• Supervulkaan Yellowstone #1
• Uitbarsting Merapi 2010
• Supervulkaan bij Napels
• Mount St.Helens

Deze OP in Fok!Wiki
• Klik hier

[ Bericht 1% gewijzigd door Frutsel op 07-12-2011 13:53:26 ]

Laatste nieuws uit vorige deel

WIN EEN DVD-BOX
Win een DVD-box over De Grootste Natuurrampen

LOKON - Indonesie

quote:

Meer dan 2000 geëvacueerd rondom Lokon
JAKARTA - Meer dan 2.000 mensen zijn ge-evacueerd nadat de Lokon vulkaan in het noordelijke puntje van Sulawesi tot uitbarsting is gekomen. Dit meldden functionarissen woensdag.

Het hoofd van het Agentschap Beheersing Rampen BPBD, Hoyke Makarawung, liet aan Antara weten dat er inmiddels 2.116 mensen van de hellingen van de vulkaan waren geevacueerd. Alle evacuees zijn naar dorpen in de directe omgeving gebracht, nog in het district Noord Tomohon.

Er zijn vier noodverblijven ingericht in drie christelijke scholen in Tomohon. De coordinerend minister van Welzijn, Agung Laksono, liet weten dat de evacuees in goede toestand waren. De Lokon vulkaan barstte maandag uit, waardoor er onder meer een veiligheidszone van 10 nautische mijlen (zo'n 18,5 kilometer) werd ingesteld rond de vulkaan.

Eerder op maandag werd de alarm-status van de vulkaan plotseling verhoogd naar de hoogste status omdat de 1.500 meter hoge Lokon vulkaan bekend staat om zijn plotseling toenemende en afnemende activiteit. De vulkaan begon om 15:50 uit te barsten, waarbij een dikke bruinige aswolk tot zeker 15 kilometer hoog de lucht in werd gestuurd.

PUYEHUE - CHILI
Uitbarsting vulkaan Puyehue (Chili)

KATLA / HEKLA - IJSLAND
Vulkanen IJsland #17 met een Grimmige Grimsvotn

SOPUTAN - INDONESIE
Vulkaan Soputan barst uit.

RIFTVALLEI - AFRIKA
De Riftvallei, Nieuwe oceaan kan Afrika in tweeën splitsen

TAAL - FILIPIJNEN
Filipijnse 'Taal' vulkaan staat op uitbarsten

quote:

Vanuatu evacuation alert as volcano rumbles
Vanuatu's Ambae volcano has begun spewing volcanic gases, and residents could be forced to evacuate part of the island.

An expert from the Vanuatu Geohazards Observatory has been sent to monitor the volcano, which has been known to trigger earthquakes.

They have measured an increase in tremor activity in the area and are expecting more explosions.

If the volcano does becomes more active, people living around it will be forced to evacuate.

Volcanologist Sylvain Todman, from the Vanuatu Geohazards Observatory, told Pacific Beat they were watching the situation very closely.

"At the moment we have sporadic explosions but the explosions are getting bigger and bigger every time," he said.

Lokon heeft inmiddels ook een eigen topic
Na Soputan barst nu ook de Lokon uit.

quote:

Op maandag 18 juli 2011 16:48 schreef Maron het volgende:
Het is niet te hopen dat deze jongens gaan 'puffen'..
http://news.nationalgeogr(...)ca-science-tsunamis/

Ah.. dat verklaart ook dit

quote:

Antarctica krijgt tsunami-alarm

Antarctica moet een systeem krijgen dat vroeg genoeg waarschuwt voor een tsunami. Dat hebben de lidstaten van het Antarcticaverdrag beslist op een bijeenkomst in Buenos Aires. Ze willen ook dat het toerisme in de zone meer aan banden worden gelegd.
Dat er ooit een tsunami Antarctica bereikt, is weinig waarschijnlijk. Maar het grootste deel van de basissen op Antarctica bevindt zich aan de kust. Bovendien nemen de wetenschappelijke, logistieke en zelfs toeristische activiteiten er toe.

Argentijns voorstel
Het voorstel komt van Argentinië. Op de huidige prognosekaarten voor tsunami's komt Antarctica niet voor, wellicht omdat de menselijke aanwezigheid er te beperkt is, zeggen de Argentijnen. De landen van het Antarcticaverdrag gaan de instituten die deze prognoses maken, nu vragen hun modellen uit te breiden tot de kusten van Antarctica en een rapport op te stellen over de risico's voor de zone.

Antarctica staat niet bekend als seismisch gebied, zeggen experts, maar de laatste jaren werden wel grote bevingen geregistreerd met het hypocentrum (de plaats onder het epicentrum waar de beving ontstaat) in de zeebodem in het gebied. Een van die bewegingen werd in 2007 geregistreerd aan de Zuidelijke Orkney-eilanden, een andere in maart dit jaar aan de Zuidelijke Sandwicheilanden.

Cruiseschepen
Op de bijeenkomst in Buenos Aires kwamen driehonderd vertegenwoordigers samen van de landen die het vijftig jaar oude Antarcticaverdrag hebben ondertekend. Ze willen ook dat er grotere beperkingen komen op het toerisme in de regio.

Sinds de jaren negentig is het aantal toeristen er sterk gestegen, tot 46.000 toeristen per jaar. Dat is tien keer meer dan twintig jaar geleden. Dat komt vooral doordat veel poolschepen na het uiteenvallen van de Sovjet-Unie werden omgebouwd tot cruiseschepen, zegt José María Acero, ondersecretaris van het Antarcticaverdrag.

Door de financiële crisis is het cruiseverkeer in de regio wel met een kwart gedaald en voor het volgende seizoen verwacht men een gelijkaardige terugval, zegt de Internationale Vereniging voor Reisorganisatoren naar Antarctica.

Temperatuur stijgt
Tijdens de bijeenkomst spraken de landen ook hun bezorgdheid uit over de gevolgen van de klimaatwijziging voor Antarctica. Volgens het VN-klimaatpanel is de gemiddelde temperatuur daar de laatste jaren vier keer sneller gestegen dan in de rest van de planeet.

De volgende bijeenkomst vindt in juni volgend jaar plaats in het Australische Hobart

quote:

Alertlevel raised for Cleveland volcano
Recent satellite images of a remote Alaska volcano along a flight route for major airlines show the mountain may be poised for its first big eruption in 10 years, scientists said on Thursday.

The Alaska Volcano Observatory has issued an eruption advisory for the 5,676 foot-tall Cleveland Volcano, located on the uninhabited island of Chuginadak in the Aleutian chain about 940 miles southwest of Anchorage.

The advisory was based on "thermal anomalies" detected by satellite, the observatory said. Those measurements indicate the volcano could erupt at any moment, spewing ash clouds up to 20,000 feet above sea level with little further warning, the observatory said.

A major eruption could disrupt international air travel because Cleveland Volcano, like others in the Aleutians, lies directly below the commercial airline flight path between North America and Asia, said John Power, scientist-in-charge at the Alaska Volcano Observatory.

The volcano's last major eruption came in 2001, when it blasted ash more than 5 miles into the sky and spilled lava from the summit crater. Cleveland has experienced several smaller eruptions or suspected eruptions since then.

So far, airlines have not changed their flight patterns because of Cleveland's heat emissions, said Steve McNutt, a University of Alaska Fairbanks scientist who works at the observatory.

Scientists are not always certain about what is happening at the remote volcano, observatory officials said. The town of Nikolski, the nearest settlement to Cleveland Volcano, is 45 miles away.

Although Cleveland is among the most active of Alaska's roughly 90 volcanoes, no seismic equipment is set up there because the costs of working in such a remote area are prohibitive, observatory officials said.

Still, Cleveland is the only Alaska volcano blamed for an eruption-caused human death in recorded history. A U.S. soldier who was stationed on Chuginadak Island during World War Two disappeared during an eruption and was presumed killed.

Without sophisticated monitors like those used to keep tabs on volcanoes closer to Anchorage and other populated areas, scientists must rely on a variety of other observations to track Cleveland's eruptions, McNutt said. Those include satellite data, eyewitness reports and video from mariners and pilots in the area.

"Cleveland is a particular bugaboo for us because it is right on the air route" with no seismic equipment, Power said.

Interessant om te gaan volgen. Cleveland kan weer gaan puffen en dan zit het internationale vliegverkeer weer met de brokken

quote:

Earthquake swarm beneith Canary Islands volcano
Recently El Hierro volcano of the Canary Islands has been experiencing a seismic swarm beneath it, which as of yesterday reached to over 700 events. Most of these events have been at Magnitudes of around 2 (+/-0.5) and are clustered beneath El Hierro whilst the depths of these earthquakes have been roughly between 9 and 16 km for the mostpart, with the exception of a few shallower and deeper quakes, the shallowest of which has been 4 km. If we look at these earthquakes in two plots here http://www.volcano-blog.com/hierro.html we can see the clustering of these earthquakes is mainly confined to an oval area at 10 km depth. El Hierro is a broadly basaltic volcano which might have been active in 1793 although this is uncertain.
So the big question is, what’s happening here? It is possible that there is magma on the move at depth, perhaps moving into a magma chamber. Does this mean that there will be an eruption? Maybe, maybe not. The majority of magma intrusions do not reach the surface, and as has been seen elsewhere, in the past, activity can cease at anytime. As of yet (to my knowledge) there have been no other signs of moving magma at the surface such as ground deformation or increased gas emission, although GPS antenna have been set up by officials at the Canary Islands. For now it is too early to tell what (if anything) will happen, so keep watching.

Overzicht van de quake-swarm

Interessant misschien? Het is volgens mij een andere vulkaan dan de 'beroemde' van LaPalma uit dit topic:
Mega tsunami door in zee vallen van eiland La Palma?

Vulkaan Cleveland lijkt zich op te maken voor uitbarsting

Cleveland gaat boem doen

quote:

Mt Karangetang spews fresh lava and ash
A VOLCANO that has been spewing lava and clouds of searing gas high into the air has let out a new, powerful burst, sending panicked villagers streaming down the sides of the mountain.

A man who fell as he was fleeing was injured, said Ludianto, head of the search and rescue team.

The victim suffered only cuts and bruises.

Mount Karangetang on Siau - part of the Sulawesi island chain - started spitting clouds of gas and lava up to 600 metres on Friday, said volcanologist Surono.

Earlier today, hot ash tumbled down its slopes triggering fresh panic.

Nearly 600 people living along Karangetang's slopes have been evacuated, said Tonny Supit, the district chief.

Indonesia lies on the Pacific "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin.

The 1784-metre mountain is one of about 129 active volcanoes in Indonesia. It's last big eruption was in August, killing four people.

quote:

Soputan status increased after ash eruption
UPDATE 14/08-17:03 UTC : Officials told the press that the alert status of Mt Soputan was also increased 1 level to III. This brings the number of volcanoes into the second highest alert level to 5.
NO volcano has the highest alert level so far.

RENEWED ACTIVITY UPDATE 14/08-16:07 UTC : The Soputan volcano once again started spewing ash clouds in the air as he did on July 3. The farmers in the surrounding villages are very concerned for their crops.
It can be called curious that the Indonesian Authorities have only an Alert level II active for this volcano (on a scale of 1 to 4), although a local Sulawesi spokesman told the press that the alert status will probably be raised today to level III. The 1784 meter high volcano spews ash until a level of 12,000 feet (3,700 meter). The density stays moderately dangerous for air traffic for approx. 55 nm (nautical miles) in a westerly direction (source VAAC).
The Indonesian NDMA reports that the first of 2 powerful eruptions started at 09:27 local time (the ash cloud climbed 1,200 above the summit crater). 7 hours later a second burst of ash followed.
Authorities have ordered a 4 km No-Go radius as the NDMA fears for avalanches and pyroclastic flows. So far there are NO reports of injuries or serious damage.

UPDATE 04/07-10:19 UTC : The people working for the Mount Soputan Geological Survey have confirmed that the volcano showed no further eruption pattern. As the mountain was covered by thick clouds, scientist have not seen any alteration of color compared to normal clouds. Therefore they conclude that the activity has stopped.
Additionally we can report that the (explosive) activity of the volcano (ash clouds) resulted in 16 flights to be postponed or canceled at Manado International Airport yesterday.

quote:

Aantal trillingen Papandayan boven normaalGARUT - Het aantal trillingen dat gemeten wordt door gevoelige instrumenten rond de Papandayan vulkaan in het district Garut in de provincie West Java laat een stijging zien. Omdat er gisteren in enkele uren tijd zes maal een trilling werd waargenomen, is besloten de alarm-status van de vulkaan te verhogen naar het derde niveau op een schaal van vier.

"Het aantal trillingen onder de Papandayan vulkaan ligt hoger dan gemiddeld normaal is," aldus Momon, dienstdoende observant op de observatiepost in Cisurupan. Het aantal trillingen wordt op dit moment twee maal daags afgelezen. In Augustus zijn in totaal al 48 trillingen geregistreerd, waar dit over de gehele maand juli nog 50 was.

Sinds de laatste uitbarsting van de Papandayan vulkaan op 11 november 2002 is het voor het eerst dat de alarm-status van de vulkaan op het derde niveau is komen te staan. Volgens Momon is er nog geen significante stijging van het water in het kratermeer gemeten. "De overige metingen laten over het algemeen nog een normaal beeld zien," legde Momon uit.

El Hierro eigen topic
Aardbevingszwerm Gran Canaria houdt aan, wat gebeurt daar?

[ Bericht 96% gewijzigd door Frutsel op 24-08-2011 12:25:12 ]

quote:

Marapi stoot rookwolk uit
BUKITTINGGI - De Marapi vulkaan in West Sumatra - niet te verwarren met de Merapi vulkaan in Midden Java - heeft gisteren opnieuw een witte rookwolk uitgestoten. Dit gebeurde tussen 9 en 10 uur in de morgen lokale tijd. De alarmstatus van de vulkaan stond al op niveau twee op een schaal van vier en ook is er een klimverbod ingesteld voor de top van de vulkaan.

Een uur voordat de witte rookwolk werd uitgestoten, produceerde de 2.891 meter hoge vulkaan ook al een kleine gitzwarte rookwolk gedurende tien minuten. Door de sterke wind werden beide wolken snel uiteengeblazen. Later op de dag ging de top van de vulkaan schuil achter een dichte mist, waardoor niet meer kon waargenomen of er nog meer rookwolken werden uitgespuwt.

Het Agentschap Beheersing Rampen BGPVMB handhaaft de alarmstatus voor de vulkaan vooralsnog. Er zijn namelijk geen verdere aanwijzigingen dat de vulkaan actiever aan het worden is. Een gebied van drie kilometer rond de top van de vulkaan is tot verboden gebied verklaard. Meetinstrumenten op diverse plekken op de hellingen van de vulkaan doen vooralsnog hun werk prima.

In de directe omgeving van de Marapi vulkaan liggen twee andere actieve vulkanen, de Singgalang en Tandikek. Op 3 augustus stootte de vulkaan een aswolk uit tot een hoogte van 1.000 meter. De laatste uitbarsting van de vulkaan was in 2005. Steden in de buurt van de vulkaan zijn onder meer Agam, Tanahdatar, Pariaman, Padangpariaman en Padangpanjang.

Marapi dus, niet Merapi

quote:

Verhoogde status voor vulkaan op Flores (Indonesie)
FLORES - Het Agentschap voor Meteorologie, Klimatologie en Geofysica (BMKG) heeft bekend gemaakt dat het de starmstatus van de Anak Ranakah vulkaan in het district Manggarai op het eiland Flores in zuidoost Indonesië heeft verhoogd naar twee, op een schaal van vier. De 2.247 meter hoge vulkaan stoot vrijwel doorlopend een kleine witte rookpluim uit, maar er is nu ook een verhoogde activiteit waargenomen in de vulkaan zelf.

De vulkaan, die eigenlijk meer een lava-koepel is, is de meest recent gevormde lava-koepel in de Pocok Leok caldera van de Ranakah vulkaan. Deze lava-koepel werd eind december 1987 gevormd. Op 11 januari 1988 barstte de vulkaan voor het laatst met kracht uit vanuit deze nieuw gevormde lava-koepel. Toen bereikte de aswolk een hoogte van acht kilometer. Ook veroorzaakte de vulkaan hete pyroclastische wolken.

Er is vrij weinig bekend over de vulkaan omdat de eerst bekende uitbarsting die van 1988 is. Sindsdien is de vulkaan ook niet meer uitgebarsten. Wel is te meten dat in de vulkaan zich meer en meer trillingen voordoen. Deze trillingen zijn echter zo klein dat ze niet door mensen gevoeld kunnen worden. Op basis van deze gegevens is wel besloten om de alarmstatus voor de vulkaan te verhogen naar twee, zeker omdat de lava-koepel van de vulkaan erg kwetsbaar is.

De vulkaan wordt actief en intensief in de gaten gehouden. De bevolking in het gebied wordt opgeroepen om altijd alert te zijn op de activiteit van de vulkaan. Ook wordt samen met lokale en regionale rampenteams bekeken of eventuele extra voorzorgsmaatregelen nodig zijn. Bezoekers mogen het gebied in de directe omgeving van de Anak Ranakah niet beklimmen bovendien.

Boom Boom... Tambora...

quote:

Eruptions reader Martin pointed out an new report from the volcanological survey in Indonesia, the PVBMG, that raises the alert level at one of Indonesia's most famous volcanoes, Tambora. Now, many of you volcano enthusiastics would remember Tambora for 1815, when it produces one of the largest eruptions in the past few thousand years. This eruption through enough material and aerosols into the atmosphere to cause significant global cooling, producing the "Year without a Summer" documented across the globe. What most people don't know is that after the 1815 eruption, Tambora has erupted at least 3 known times, all in the scale of VEI 0-2 (rather than the VEI 7 of 1815).

Why do I mention this? Well, with any news of increased seismicity and steam plumes at a volcano like Tambora, you can be sure the fear/panic-mongers will come out in full force. The PVBMG reports says that since April 2011, the volcano has seen intermittent swarms of earthquakes and now at the end of August, there seems to be an increase in these shallow, volcanic earthquakes along with the presence of tremor. Combine that in observations of steam plumes rising tens of meters over the edge of the caldera rim, then you might have the signs of impending activity - thus the elevation of the alert status from Level I to II. Now, what kind of activity might we expect? Most likely we would expect something small, akin to the VEI 0-2 eruptions in 1819, 1880 and 1967, which were mainly lava flows and domes confined to the caldera floor, and most definitely not another VEI 7 event like the 1815 eruption.

De Tambora (Was daar laatst niet een quake in de krater van 5.0 ofzo?)
Die zouden we niet graag zien ploffen denk ik Maar even volgen denk ik.. ondanks dat de verwachtingen niet groots zijn, maar mogelijk wel potentieel voor doomdenkers

Voor de nietwetenden: Tambora 1815 - the year without summer

[ Bericht 0% gewijzigd door Frutsel op 30-08-2011 15:54:32 ]

quote:

MEXICO CITY — The Popocatepetl (po-po-ka-TEH-peh-tel) volcano south of Mexico City is shooting blasts of ash from its crater.

Mexico’s national disaster prevention agency says the volcano has spewed ash more than a half mile (a kilometer) into the sky four times Tuesday. It says there is a possibility ash could fall onto Mexico City overnight.

The agency is urging people to stay at least 7 miles (12 kilometers) from the crater.

The 17,886-foot (5,450-meter) volcano is about 40 miles (65 kilometers) southeast of the capital

quote:

Tambora alert status raised again
Dompu, West Nusa Tenggara. Provincial authorities raised the alert level of Mount Tambora to the second-highest available as observers noted an increase of volcanic activity in the volatile mountain.

“On August 30, we recorded seven volcanic earthquakes and since Sept. 8 the frequency of the quakes rose substantially, to between 12 and 16 per day,” Husnuddin, head of the West Nusa Tenggara Disaster Mitigation Agency (BPBD), told the Jakarta Globe on Sunday.

The BPBD chief said a team of observers had been immediately deployed to Mount Tambora.

The volcano, which was the site of the world’s deadliest eruption on record, showed no apparent visual signs of any upcoming eruption, but data collected on mechanical instruments gave cause for concern.

“We still hope Mount Tambora’s alert level will not increase further. We hope we can lower the status of the volcano. Let us all pray everything will return to normal,” Husnuddin said.

Abdul Haris from the Mount Tambora observatory station said the heightened alert status meant an eight-kilometer exclusion zone was being imposed.

“We fear there will be toxic gas as a direct result of the increased activity,” he said.

Husnuddin said the BPBD swiftly met with leaders of the three districts surrounding the volcano — Dompu, Bima and Sumbawa.

The agency also held talks with the leadership of Pekat and Tambora, two Dompu subdistricts near Tambora’s crater, to discuss possible evacuation plans if the alert status reaches the highest level. The agency also had identified locations for possible shelters to house people living around the volcano.

There are four villages in the two subdistricts that are about eight kilometers from the crater.

The BPBD requested several organizations be on stand-by, including the National Disaster Mitigation Agency (BNPB), the National Search and Rescue Agency (Basarnas) and the country’s Armed Forces, which have already deployed officials to several response stations in the two subdistricts.

Two main evacuation routes for people in the four villages have also been identified.

Damn, gaat die dan toch rare dingen doen?
Er zou ook nog een andere vulkaan op Flores rommelen, de Lewotobi

Etna heeft ook een eigen topic
Uitbarsting Etna

Maar het is jammer dat zaken als Ali B en Patricia P belangrijker zijn op andere delen van Fok dan dat nieuwsberichten uit dit deel eens wat meer aandacht krijgen. Maar ja, je went er aan.

[ Bericht 11% gewijzigd door Frutsel op 29-09-2011 10:05:37 ]

quote:

Vulkaanuitbarsting Tenerife helpt aardverschuivingen te begrijpen

AMSTERDAM - De ontdekking van een grote vulkaanuitbarsting op Tenerife van 733.000 jaar geleden werpt nieuw licht op aardverschuivingen. Zo is men in de toekomst mogelijk beter voorbereid op de gevolgen van dit soort grote catastrofes.

Vulkanologen van de Universiteit van Leicester ontdekten op het Canarische eiland Tenerife een aardverschuiving ten gevolge van een grote vulkaanuitbarsting waarbij een deel van de zijkant van de vulkaan de zee in verdween.

Ze publiceerden hun bevindingen in de oktober-editie van het tijdschrift Geology.

Bijzonder

Het is bijzonder dat niet vrijwel de hele aardverschuiving door de uitbarsting de zee in verdwenen is. "Het is een van de best bewaarde en toegankelijke voorbeelden van zo’n ontzagwekkend fenomeen, omdat het puin van zulke aardverschuivingen zich meestal over de oceaanbodem verspreid en daardoor ontoegankelijk voor verdere studie", verklaart Dr. Branney, een van de onderzoekers.

Het achtergebleven puin en gruis op Tenerife bevat onder andere blokken van snel afgekoeld stollingsgesteente. Radioactieve mineralen in de gestolde lava maakten het voor de onderzoekers makkelijk om zeer precies de datum van de uitbarsting te bepalen.

Klimaatverandering

Klimaatverandering wordt vaak aangewezen als reden voor aardverschuivingen op eilanden in de oceaan. Dat was nu niet het geval. Een groeiende koepel van hete lava duwde van binnenuit de zijkant van de vulkaan naar buiten toe.

Zulke gebeurtenissen zijn niet ongewoon, maar komen zeer onregelmatig voor. Ze begrijpen is daarom van belang omdat de effecten duizenden kilometers verderop grote problemen kunnen veroorzaken.

quote:

Zes Indonesische vulkanen op verscherpt toezicht
JAKARTA - Hoewel inmiddels zes vulkanen onder scherp toezicht staan vanwege hun verhoogde activiteit, heeft het Nationaal Agentschap Rampen BNPB laten weten dat op dit moment er geen noodzaak is tot het evacueren van inwoners.

Een woordvoerder van BNPN, Sutopo Purwo Nugroho zei zondag dat er zes vulkanen op een verhoogde alarm-status staan op dit moment; de Tambora vulkaan in West Nusa Tenggara, de Anak Ranaka in Oost Nusa Tenggara, de Papandayan in West Java, de Karangetang en Lokon in Noord Sulawesi en de Anak Krakatau in de Sunda Straat.

"Deze vulkanen staan op dit moment op alarm-status drie op een schaal van vier. Dit betekent dat ze vulkanisch zo actief zijn dat dit zou kunnen leiden tot een uitbarsting of een ramp," aldus Nugroho via SMS aan de Jakarta Post.

Nugroho voegde toe dat de Anak Krakatau vulkaan op dit moment zo'n 5.000 trillingen per dag liet registreren. Er is een twee kilometer grote zone rond de top van de vulkaan als onveilig bestempeld. De vulkanen worden de klok rond geobserveerd door instrumenten en personen.

quote:

Swarm of earthquakes around Mt.Rainier
SEATTLE -- It may not amount to much, like so many times before, but seismologists are paying close attention to a recent swarm of earthquakes on Mount Rainier.

Data from the Pacific Northwest Seismic Network show at least seven earthquakes in the last two weeks around the mountain.

One of the strongest was last Friday, when a 3.4 magnitude quake struck in the afternoon near Ashford. Earlier that day, a 2.9 magnitude quake shook beneath Mount Rainier.

Thousands of tiny quakes preceed the erruption of Mt. St. Helens seven years ago as magma was being pushed upward from deep below. As they were then, scientists say these quakes are also shallow, but not necessarily a warning sign of anything immediate.

"It helps seeing these types of events over, in my case, decades," said University of Washington seismologist Steve Malone.

Seismologists are also watching Eastern Washington, where there have been at least four earthquakes in the last few days around a small area on the Columbia River just north of Richland.

Coincidentally, a 3.4 magnitude quake struck that area the same day as the Ashford quake near Mount Rainier. However, scientists say the two swarms are not connected.

"We just have to pay attention," said Malone. "Just keep watching it."

Had het net ook gelezen inderdaad.
Maar goed, daar is dit 'centrale' topic ook voor... alles wat gemeld wordt over vulkanen, kan hier in...

Als het echt slim wordt, krijgt Rainier wel een eigen topic

quote:

Earthquakeswarm at Mauna Kea Hawaii
After yesterday’s post on the “swarm” at Rainier (which apparently rubbed a lot of people the wrong way), I was hesitant to post on the news coming from Mauna Kea right away, but if you’re looking for a real swarm of earthquakes at a volcano, look no further (see below). Since early yesterday (Hawaii time), the volcano has experienced at least 38 earthquakes, some as large at M4.5, all centered NW of the main summit of Mauna Kea, all at depths between 14-19 km (see below), all below the crust under the Big Island. This is what a suspicious swarm looks like, where we have a strong focus of seismicity at depth under an active volcano – the question now is how persistent will this swarm be. More likely than not, these earthquakes will lead to nothing – and HVO says these earthquakes are “most likely caused by structural adjustments within the Earth’s crust due to the heavy load of Mauna Kea”. Remember, Mauna Kea is a huge point weight on the crust and upper mantle below Hawai’i, towering over 4,200 m / 13,800 feet above sea level, thus about 9,000-10,000 m above the seafloor, so a lot of stress can accumulate from the mass of the volcano. This means earthquakes are likely common as that stress builds.

Remember, Kilauea and Mauna Loa are not the only active volcanoes on the Big Island of Hawai’i. Haulalai last erupted as recently as 1801, while Mauna Kea, the 2nd oldest shield volcano on the island last erupted only ~4,470 years ago. For argument’s sake (not that this swarm looks to be leading to any eruption), Mauna Kea is located on the back side of the active plume head for Hawai’i – so we think the “hotspot” is located under Kilauea. However, even after the plate has passed over the hotspot, volcanism can continue for some time – the “post-shield” phase of the volcano. In the very small likelihood that these earthquakes under Mauna Kea are leading to a new eruption, it is likely to be a small eruption of alkalic basalt (as opposed to the tholeiitic basalt at Kilauea – these terms just refer to the extent of melting that occurred to form the magma). Interestingly, most of the recent activity at Mauna Kea has been on the NE or S flanks, not the NW. Mauna Kea has felt swarms before, so this by no means something is in the works. However, considering the astronomical infrasructure at the summit of Mauna Kea, it needs to be watched closely. Even this increased seismicity can’t be good for highly sophisticated telescopes such as those on Mauna Kea.

quote:

Rapidly Inflating Volcano Creates Growing Mystery
Should anyone ever decide to make a show called "CSI: Geology," a group of scientists studying a mysterious and rapidly inflating South American volcano have got the perfect storyline.

Researchers from several universities are essentially working as geological detectives, using a suite of tools to piece together the restive peak's past in order to understand what it is doing now, and better diagnose what may lie ahead.

It's a mystery they've yet to solve.

Uturuncu is a nearly 20,000-foot-high (6,000 meters) volcano in southwest Bolivia. Scientists recently discovered the volcano is inflating with astonishing speed.

"I call this 'volcano forensics,' because we're using so many different techniques to understand this phenomenon," said Oregon State University professor Shan de Silva, a volcanologist on the research team.

Researchers realized about five years ago that the area below and around Uturuncu is steadily rising — blowing up like a giant balloon under a wide disc of land some 43 miles (70 kilometers) across. Satellite data revealed the region was inflating by 1 to 2 centimeters (less than an inch) per year and had been doing so for at least 20 years, when satellite observations began.

"It's one of the fastest uplifting volcanic areas on Earth," de Silva told OurAmazingPlanet."What we're trying to do is understand why there is this rapid inflation, and from there we'll try to understand what it's going to lead to."

The peak is perched like a party hat at the center of the inflating area. "It's very circular. It's like a big bull's-eye," said Jonathan Perkins, a graduate student at the University of California, Santa Cruz, who recently presented work on the mountain at this year's Geological Society of America meeting in Minneapolis.

Scientists figured out from the inflation rate that the pocket of magma beneath the volcano was growing by about 27 cubic feet (1 cubic meter) per second.

"That's about 10 times faster than the standard rate of magma chamber growth you see for large volcanic systems," Perkins told OurAmazingPlanet.

However, no need to flee just yet, the scientists said.

"It's not a volcano that we think is going to erupt at any moment, but it certainly is interesting, because the area was thought to be essentially dead," de Silva said.

Uber-Uturuncu?

Uturuncu is surrounded by one of the most dense concentrations of supervolcanoes on the planet, all of which fell silent some 1 million years ago.

Supervolcanoes get their name because they erupt with such power that they typically spew out 1,000 times more material, in sheer volume, than a volcano like Mount St. Helens. Modern human civilization has never witnessed such an event. The planet's most recent supervolcanic eruption happened about 74,000 years ago in Indonesia.

"These eruptions are thought to have not only a local and regional impact, but potentially a global impact," de Silva said.

Uturuncu itself is in the same class as Mount St. Helens in Washington state, but its aggressive rise could indicate that a new supervolcano is on the way. Or not.

De Silva said it appears that local volcanoes hoard magma for about 300,000 years before they blow — and Uturuncu last erupted about 300,000 years ago.

"So that's why it's important to know how long this has been going on," he said.

To find an answer, scientists needed data that stretch back thousands of years — but they had only 20 years of satellite data.

Volcano rap sheet

"So that's where we come in as geomorphologists — to look for clues in the landscape to learn about the long-term topographic evolution of the volcano," Perkins said.

Perkins and colleagues used ancient lakes, now largely dry, along the volcano's flanks to hunt for signs of rising action.

"Lakes are great, because waves from lakes will carve shorelines into bedrock, which make lines," Perkins said.

If the angle of those lines shifted over thousands of years — if the summit of the mountain rose, it would gradually lift one side of the lake — it would indicate the peak had been rising for quite some time, or at least provide a better idea of when the movement began.

The local conditions, largely untouched by erosion or the reach of lush plant and animal life, lend themselves to geological detective work, Perkins noted.

"It's a really sparse, otherworldly landscape," Perkins said. "Everything is so well preserved. There's no biology to get in the way of your observations."

Perkins said that surveys conducted on the lakes last autumn didn't indicate long-term inflation. However, tilting lakes are only one indicator of volcano growth, he said.

De Silva said the geological detective team is working to combine data from a number of sources — seismic data, GPS data, even minute variations in gravity — to pin down when and why the mountain awoke from its 300,000-year-long slumber, and better predict its next big move.

quote:

Op zaterdag 22 oktober 2011 18:04 schreef stan12 het volgende:

On the brink: Tremors increase at Anak Krakatau to 5,000 a day
Posted on October 22, 2011 by The Extinction Protocol
October 22, 2011 – SUMATRA, Indonesia –Several earthquakes have struck near south Sumatra of the 5.0 and 5.1 magnitude range today- making a tense situation on the volcanically-dotted archipelago potentially even more volatile. The Anak Krakatau volcano is showing signs of increased seismic activity. Authorities fear the volcano is building towards an eruption that could dwarf the one which occurred in 2007. Indonesia’s Volcanology and Geological Disasters Mitigation Center reported the numbers of seismic tremors now registering from the volcano have exceeded 5,000 a day. There are also reports of a gaseous mist which has seeped from the volcano and have enshrouded it in a yellowish haze- something that has never been observed at the volcano before. Anak Krakatau was placed on orange (level 3) status alert on September 30, 2011. –The Extinction Protocol

http://theextinctionproto(...)katau-to-5000-a-day/

Thx! Krakatau heeft trouwens ook een eigen topic

Hudson Volcano active after 20 years



The National Service of Geology and Mining (SERNAGEOMIN) – Volcano Observatory of the Southern Andes (OVDAS), announced that from the early hours of last night there has been increased seismic activity related to the Hudson volcano. At 19:08 local time, an earthquake Volcano-tectonic (VT), magnitude (ML) equal to 4.6 located 7 km to the NW edge of the caldera, at a depth of 19 km, which was followed by the occurrence of a seismic swarm starting at 21:49 hrs, includes more than 100 seismic events recorded until the time of this report, whose depths range from 15 to 25 km. It notes that 15 events recorded magnitudes (ML) greater than 3.0 and three (3) of these magnitudes (ML) greater than 4.0, all characterized by having more to do with broken rock (VT) at 00: local 20 hours today, Wednesday, October 26, an earthquake associated with fluid movement and characterized by very low frequency (long period – VLP), located in the same area at a depth of 15 km, with a magnitude (ML) equal to 4.3. The seismic swarm continues at the time of issuance of this report with less intensity. The preceding activity indicates that the volcanic system has experienced changes in their dynamics, possibly associated magmatic activity at depth, which in the future the system can lead to imbalance.

Pre-eruption: The Chilean authorities decided to raise the alert level to red and preventive evacuations in an area of ​​40 kilometers around Mount Hudson. The column emission from the eruption reached 1 km in height. The information was confirmed this afternoon from Vice President Rodrigo Hinzpeter Onemi, from where he said he “cannot rule out an eruption,” so it was decided to evacuate people living in that radius.” An over-flight of the area showed a column of smoke and gases out of the cone of the Hudson. In addition, there were some signs of an avalanche in the vicinity. –Diarioandino
Hudson’s explosive history: “Large eruptions around 4750 BCE and 1890 BCE are believed to have been of Volcanic Explosivity Index VEI 6; these are probably responsible for the large caldera. The 4750 BCE eruption may have wiped out many if not all groups of early man living in central Patagonia at that time, based on evidence from the Los Toldos archaeological site. Before 1970, little was known about the mountain. Minor eruptive activity began in 1970 and melted parts of the glacier, raising river water levels and leading to the identification of the caldera. In August-September 1971, a moderate eruption (VEI 3) located in the northwest area of the caldera sent ash into the air and caused lahars from the melting of a large portion of the glacier. The lahars killed five people; many more were evacuated. It’s last eruption in August to October 1991 was a large plinian eruption with a VEI of 5, that ejected 4.3 km3 bulk volume (2.7 cubic km of dense rock equivalent material). Parts of the glacier melted and ran down the mountain as mud flows. Due to the remoteness of the area, no humans were killed but hundreds of people were evacuated from the vicinity. Ash fell on Chile and Argentina as well as in the South Atlantic Ocean and on the Falkland Islands. In addition to the ash, a large amount of sulfur dioxide gas and aerosols were ejected in the eruption. These contributed to those already in the atmosphere from the even larger Mount Pinatubo eruption earlier in the year and helped cause a worldwide cooling effect over the following years. Ozone was also depleted, with the Antarctic ozone hole growing to its largest levels ever recorded in 1992 and 1993.

quote:

Nyamuragira volcano erupts

November 7, 2011 – DRC, AFRICA – The Nyamulagira volcano located 22 km from the city of Goma, capital of the province of North Kivu, in eastern DRC, has been erupting since Sunday around 8:30 p.m., a said Monday the Goma Volcano Observatory. According to volcanologists, the people of Goma, are not directly threatened by the eruption of this volcano because the lava flows are directed towards the Virunga National Park (Virunga National Park). . However, had he added, people should be held in compliance with the rules of hygiene to protect against such volcanic ash released by the volcano. During the last eruption of this volcano in January 2010, the lava had burned over 11 hectares of the forest of the Virunga Park, which extends over 790,000 ha. To the World Heritage Site by UNESCO since 1979, the Virunga National Park is home to various species of mammals (hippos, gorillas …), reptiles and birds. The eruptions of Nyamulagira May 2004 and November 2006 had made the most active volcano in Africa. Nyamulagira and Nyiragongo volcanoes are two of eight active volcanoes that make up the Virunga chain, located in the Virunga National Park in eastern DRC. In January 2002, a lava flow of Nyiragongo volcano had destroyed 80% of the border city of Rwanda. Le Nyamulagira volcano erupts at intervals of about 2 years in contrast to Nyiragongo is unpredictable

quote:

The erupting Nyamulagira (also known as Nyamuragira) volcano reddens the sky on Sunday in the Democratic Republic of the Congo. (See an interactive cutaway of the Nyamulagira volcanic region.)

Nyamulagira, which generally erupts every two years, rumbled to life at 8:06 p.m., spewing lava, smoke, and ash throughout Virunga National Park. The volcano sits within the park, about 25 miles (40 kilometers) north of the city of Goma (map).

The park's communications officer, LuAnne Cadd, first got a phone call about the event from rangers, who'd heard noises like gunshots, she said.

Cadd immediately went outside to take pictures of the nighttime spectacle, which was occurring an estimated 6 to 12 miles (10 to 20 kilometers) west of park headquarters in Rumanbago, she said. (See a park map.)

"What's quite astonishing is how bright it is, how it lights up the sky with a red glow, and the sound. We can hear the dull roar of it, especially at night in our tents," she told National Geographic News via email.

"I'm actually looking at it while I'm talking to you—it's so amazing, just a monstrous fountain" of lava, Cadd said.

"It's mesmerizing and hard to pull your eyes away from it."

Experts say the volcano could continue erupting for weeks and even months, Cadd added.

quote:

Seismic activity beneath Santorini volcano continues to be slightly above normal levels.
Beginning since July this year, an there is elevated activity in a SW-NE trending zone passing through Nea Kameni and the submarine Kolumbos volcano NE of Santorini.
The alignment (also known as the Kameni and Kolumbus lines) is a ca. 2 km wide zone parallel to a tectonic horst and graben structure of the crystalline basement of the area. Most of the known volcanic vents of Santorini during the past 2 million years were located on this alignment, more precisely either on its southern boundary (Kameni line) or on its northern boundary (Kolumbus line).
Lacking other data sources, the information visible on the location and number of earthquakes is too weak, other than to vaguely speculate that the current earthquake activity around Santorini could be a precursor to new activity from this volcano. Santorini's last eruption was in 1950.

Congolese vulkaan bezorgt toeristen foto van hun leven

eigen topic

quote:

Popocatepetl volcano triggers plume 7km high
Amecameca • The Popocatepetl volcano registered an explosion that caused a plume height of 7 kilometers with emission of ash, gas and steam from the crater, and land movement could be felt in Amecameca and even the neighboring municipality of Tlalmanalco .

Civil Protection Director Amecameca, Javier Alonso Meneses said that due to the explosion at 12:02 on Sunday, was ejected incandescent material fell to 8 miles away in parts of Canada Nexpayantla, Amecameca, which originated a fire, which is being stifled by rescue workers.

Relief Corps of the town maintain communication with officials of the eight delegations of the municipality to inform them about the event and avoid panic situations.

Alonso Meneses said that according to the National Center for Disaster Prevention (Cenapred), another more severe scenario, there could be similar events, but said that is informing the public about precautionary measures to be undertaken.

People living in nearby areas felt a vibration after the crash.

Early reports indicate that the explosion was caused by the magnitude of the cone was covered. The fumalora is directed towards the area of ​​Puebla.

quote:

Fuego spews ash
The Guatemalan geophysical survey SERNAGEOMIN reports increasing explosive activity from Fuego volcano, one of the country's most active volcanoes. Fuego was observed producing ash clouds reaching 1500-2000 m above the summit crater (at ca. 3600 m altitude) which drifted SW and reached up to 20 km distance where they produced some ash fall, reported in the communities of Panimaché, Morelia, Sangre de Cristo, and Santa Sofía.
The explosions were accompanied by moderate to strong booming noises and shock waves that could be felt in up to 15 km distance. Near-constant rock avalanches are observed on the upper slopes beneath the summit crater, some of which reach the vegetated areas.

quote:

Exhalacion del volcan Popocatepetl el 20/11/2011

quote:

Op vrijdag 25 november 2011 21:50 schreef Resistor het volgende:
Dan sta je toch even raar te kijken, als 'opeens' (als leek zijnde) een vulkaan voor je ogen uitbarst.

Lijkt me dat het nog gevaarlijk kan zijn ook... maar goed, dat ding barst wel vaker uit dus misschien weten de bewoners wel wanneer het echt link wordt en wanneer niet.

quote:

Colombia waarschuwt voor uitbarsting Galeras
Het Colombiaans geologisch instituut (Ingeominas) heeft de evacuatie aanbevolen van zowat achtduizend mensen die in de buurt wonen van de vulkaan Galeras, in het zuiden van het land. De vulkaan toont een verhoogde activiteit en er wordt gevreesd voor een uitbarsting.

Het gaat om een waarschuwing van het niveau "oranje", het tweede niveau op een schaal van vier. "Dat houdt in dat er tekenen zijn van een erg waarschijnlijke uitbarsting in de komende dagen of weken", aldus Marta Calvache, onderdirecteur van Ingeominas.

De 4.270 meter hoge vulkaan, die niet ver van de grens met Ecuador ligt, is de laatste twintig jaar constant actief. De meest dodelijke recente uitbarsting dateert van 1993. Daarbij kwamen negen mensen om het leven. (belga/jv)

quote:

Alertstatus Mt Sindoro (Java Indonesia) raised
After the activity continued to increase since last October, the status of Mount Sindoro in Waterford and Wonosobo regency, Central Java, Monday (5 / 12) night, upgraded its status from active to normal alert.

Sulfatara bursts of smoke and hot mud around the crater of Mount Sindoro getting bigger and growing number. In addition, the seismic activity of Mount Sindoro also increasing, so the Center for Volcanology and Geological Hazard Mitigation, improve the status of Mount Sindoro.

Increase in alert status of Mount Sindoro set on Monday around 20.00 West Indonesia Time. Communities are asked not to panic despite increased alert status. Since the 1970 phreatic eruption ago, Mount Sindoro ralatif quiet activities. (Riz)

quote:

Kolumbos submarine volcano (Santorini, Greece): 3.2 magnitude earthquake
At 19h22 GMT (21h22 local time), a 3.2 earthquake occurred at the little-known submarine volcano Kolumbos ca. 8 km NE of Santorini, Island, Greece. This marks one of the largest events in recent months.

The submarine volcano whose peak rises to just 18 m below sea level, is located on the tectonically active SW-NE fault system across Santorini which confines most volcanic vents of the Santorini volcanic complex in the past 500,000 years.

Kolumbus volcano last erupted in September 1650 following a year of frequent earthquakes. The eruption produced a large explosive pumice eruption, with ash fall recorded as far as Turkey, and built a temporary island. The main phase of the eruption triggered a devastating tsunami. Toxic gasses killed more than 25 people and hundreds of livestock on Santorini by suffocation (probably H2S).

There is no reason to state that new activity from Santorini or Kolumbus is likely in a foreseeable future but on the other hand, there are very few data available, unfortunately, to judge the situation.

We regret that the Greek monitoring institutes are not publishing more details about the ongoing activity. Access to important earthquake details such as as their depth, are not published (they are available for earthquakes in all the other regions in Greece, raising some suspect why not for Santorini...)

quote:

Vulkaanuitbarsting bij Yemen
Lokale vissers uit Salif in Yemen hebben maandagmelding gemaakt van een vulkaanuitbarsting in de Rode Zee. Het fenomeen vindt plaats bij Saba Island, die deel uit maken van de Al-Zubair archipel. De vulkaan bevindt zich op circa 30 zeemijlen van Salif City.

Volgens de vissers kan de vulkaan van afstand goed worden waargenomen en lavabommen zouden 20 tot 30 meter hoog het water uit schieten. Het zou de eerste vulkaan zijn die in dit gebied actief wordt waargenomen.

Tijd voor foto's en video's

quote:

Op dinsdag 3 januari 2012 08:28 schreef marcel-o het volgende:
Was deze al bekend?

zie ook
(Super)vulkaan Laacher See Duitsland:Eerste 2012 doombericht een feit?

Eigen topic voor Rode Zee uitbarsting
Vulkaanuitbarsting in de Rode zee

quote:

Seven Indonesian volcanoes at level-3-alert status
JAKARTA: The Centre of Vulcanology and Geological Hazard Mitigation (PVMBG) on Thursday declared that seven out of 127 volcanoes in Indonesia are in danger status of level III (alert), according to China’s Xinhua news agency.

The volcanoes are namely Mount Papandayan in West Java province, Mount Lokon and Mount Karangetan of North Sulawesi province, Mount Kawah Ijen in East Java province, Mount Anak Krakatau in the border of Banten and Lampung provinces, Mount Gamalama at North Maluku province and Mount Lewotolo in East Nusa Tenggara province, respectively.

Out of the seven volcanoes, authorities are focusing on Mount Kawah Ijen, Mount Gamalama and Mount Lewotolo as their eruption impact is the biggest compared to others, said Head of the National Agency of Disaster Mitigation BNPB) Syamsul Muarif.

He said that the BNPB and regional agencies of disaster mitigation are enhancing preparation and planning to anticipate the impact of the volcanoes activities.

Explaining further, he said that Mount Kawah Ijen contains huge danger if it erupts as it threatens as many as 9,000 people living surround the volcano.

“The biggest threat of Mount Kawah Ijen is not hot cloud, flamed material launch or volcanic ash, but is within its volcanic lake containing 30 million metre cubic of water with deadly acid level,” he said, expressing disappointment that people refuse to evacuate despite several warnings.

While, increasing activities of the Mount Gamalama will expose and force, 638 people to take refuge. Last year, there people were killed by cold lava flood of the volcano following heavy rain on the top of the volcano.

Mount Lewotolo, with eruption type of explosive holds primary danger of volcanic bombs and hot cloud. However, Syamsul said that data shows that there has been no strong eruption that claims lives since 1660.

Although Mount Lokon in the city of Tomohon of North Sulawesi has erupted on Dec 27, last year, he said such incident still does not force people to take refuge.

“Mount Anak Krakatau that erupts almost every day with small intensity does not pose any danger to people as it locates in a strait connecting the islands of Java and Sumatra.

The volcano, he said is in a growth phase and there is a small possibility that it erupts like what happened in 1883, triggering strong tsunami and claimed thousands of lives. – Bernama

quote:

Evacuaties na activiteit Lewotolo vulkaan in Indonesie
KUPANG, OOST NUSA TENGGARA - Honderden mensen in de buurt van de Lewotolo vulkaan op het eiland Lembata in de provincie Oost Nusa Tenggara zijn donderdag geëvacueerd nadat de vulkaan plotseling in activiteit toenam. Dit meldde persbureau Antara.

Zo'n 500 dorpelingen hebben hun huizen verlaten en zijn naar het stadje Lewoleba getrokken. Er zal bovendien snel een bijeenkomst gehouden worden op regionaal niveau om te kijken welke acties er verder nodig zijn. Dit meldde vice-districtshoofd Viktor Mado Watun van lembata.

Er komt op dit moment een dikke zwarte rookwolk uit de krater van de vulkaan. In het gebied is bovendien een sterke zwavellucht te ruiken. Ook produceert de vulkaan regelmatig een donderend geluid. Inwoners besloten dan ook en masse om hun dorpen te verlaten om veiliger gebieden op te zoeken.

Er is vanuit de overheid nog geen officieel evacuatie-plan opgesteld. Wel werd de alarm-status van de vulkaan in de voorbije dagen twee maal verhoogd, van status 1, normaal, naar status drie, op een schaal van vier.

quote:

Chilian ONEMI raises status of Lascar Volcano
This first came up in the news yesterday, but I thought it deserved its own spot. Lascar, one of the more active volcanoes of northern Chile, was placed on heightened alert status by the ONEMI (Chilean Emergency Management) on advice from the SERNAGEOMIN (Chilean Geologic Survey). The latest report from Lascar says that over 300 small earthquakes (pdf) have occurred at the volcano in the last 26 hours, leading to an elevation of its status to Yellow – however, there have been no indications of increased fumarolic activity at the volcano. Lascar has the potential to produce a large eruptive column – the 1993 eruption sent ash as fall east as Buenos Aires – with pyroclastic flows that could reach nearby towns such as Talabre. The volcano has been through a number of cycles of significant explosive activity over its >43,000 year history. However, recent activity is mostly lava dome formation in the summit crater followed by crater collapse and vulcanian to plinian explosive eruptions such as the major eruption of April 1993. However, it also have the potential to produce small explosions that will only dust ash on the countryside surrounding the volcano as it has done at least 6 times in the last decade. ONEMI is preparing for possible evacuations for people near the volcano – mostly either miners in the area or tourists at San Pedro de Atacama. If anything does occur, there is a webcam pointed at Lascar to see the action.

quote:

25 volcanoes in Indonesia show abnormal activity or are on alertstatus
Padang, West Sumatra. Twenty-five volcanoes in Indonesia are now showing abnormal activity or have been put on alert or watch status, presidential special aide Andi Arief said here on Saturday.

“According to official data, 25 volcanoes are now under alert or watch status and they must be given priority with regard to disaster mitigation planning at district or city levels,” he said at a workshop on journalists’ role in disaster management.

He said in West Sumatra there were two volcanoes that need to be closely watched, namely Mount Marapi and Mount Talang, as they are still under alert status.

Mount Marapi is located in Agam and Tanahdatar districts and rises 2891 meters above sea level, and Mount Talang (2597 meters above sea level) in Solok district was located around 40 kilometers from the provincial capital Padang.

Apart from the two volcanoes, the government and regional disaster management agencies were also giving priority attention to Mount Papandayan in West Java, Mount Karangetan and Lokon in North Sulawesi, Mount Ijen in East Java, Mount Gamalama in North Maluku, Mount Krakatau in Banten and Lampung and Mount Lewoloto in East Nusa Tenggara.

He said “it is not impossible that volcanoes that are now still normal could change to become abnormal due to earthquakes that have happened to trigger magma in the mountains to increase their activity, and therefore alertness and readiness of the people must continue to be maintained.”

Andi said earthquakes below five on the Richter Scale could trigger magma in the volcanoes to rise and so people must not only be alert over big but also small tremors.

The 4.4 magnitude earthquake like the one in Singkawang, West Kalimantan, is one of the examples, where people had never predicted before that it could happen there, he said.

“The small magnitude quake is now being studied by researchers with regard to minimizing the damage in case an eruption happens in the country as there are a lot of volcanoes in Indonesia,” he said.

Theorie: Aardbevingen Christchurch voortekenen van vulkaanuitbarsting?