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  Moderator vrijdag 1 maart 2019 @ 11:27:28 #1
8781 crew  Frutsel
pi_185316902
registreer om deze reclame te verbergen
fuego-volcano.jpg


Overal in de wereld kom je vulkanen tegen. Onder water, in bergruggen of onder gletsjers. Ook zijn er vulkanen waar niemand het bestaan nog van weet of waar we pas sinds kort achter kwamen dat het daadwerkelijk een vulkaan is.

In dit topic kun je alle informatie kwijt over vulkanen, je kunt vragen stellen over vulkanen of uitbarstingen maar vooral kun je hier op de hoogte blijven van de recentelijke ontwikkelingen van vulkanen overal ter wereld.

Voel je vrij om mee te posten. Zie je ergens een interessant artikel, heb je een nieuwsbericht, post het hier en doe gezellig mee :)

Wat is een vulkaan

Waar bevinden zich de vulkanen dan?
De meeste vulkanen bevinden zich rondom de tektonische platen van onze planeet. Daar waar de aardplaten langs of onder elkaar schuiven vinden aardbevingen plaats of is er vulkanische activiteit.

Een uitzondering op deze regel zijn de zogenaamde 'hot-spots'. Dit zijn plaatsen op aarde waarbij magma uit de aardmantel door de aardkorst naar boven komt. Voorbeelden hiervan zijn de eilanden van Hawaii en de Canarische Eilanden groep. Maar er zijn er meer.

De meeste vulkanen liggen rondom de zogenaamde 'Ring of Fire'.

De zogenaamde Ring van Vuur is een bijna ringvormige keten aan vulkanisch actieve gebieden. Deze Ring "verbindt" zo de Zuidelijke Pacifische Oceaan nabij Nieuw_Zeeland met de klok mee over Kamtsjatka en Alaska tot aan zuid-Chili.

Ring van Vuur
ringfire.gif


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.

Overige vormen
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.

Supervulkanen
Naast de 'reguliere' vulkanen hebben we op aarde ook 'supervulkanen'. Dat zijn vulkanen die in staat zijn om tot catastrofale uitbarstingen te komen die het leven op de hele planeet kunnen be飊vloeden. Zij kunnen bijvoorbeeld een nieuwe ijstijd in gang zetten. De laatste uitbarsting van een supervulkaan was die van Toba (Sumatra) zo'n 74.000 jaar geleden. De bekendste supervulkaan is vermoedelijk Yellowstone Park in de Verenigde Staten. De dichtstbijzijnde supervulkaan is de Campi Flegrei bij Napels

Heeft Nederland een vulkaan?
Jazeker! De naam ervan is Zuidwalvulkaan, en ligt 17 km 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. De vulkaan was actief in het Laat-Jura, zo'n 152 miljoen jaar geleden.

Maar slapen vulkanen echt en zijn ze echt dood? Daar verschillen wetenschappers van mening over. Langere tijd werd ook gedacht dat bijvoorbeeld de supervulkaan in de Eifel dood en begraven was maar recente studies hebben uitgewezen dat deze zeker niet dood is. Sterker nog: Onlangs werd bekend dat de magmakamer van de Laacher See vulkaan zich weer langzaam aan het vullen is.

Actueel Actieve vulkanen
active-volcano-map.jpg
Met dank aan Volcano Discovery


Belangrijke Links
Status vulkanen Indonesie
Volcano webcams all over the world
BBC-How volcanoes work
Smithsonian / USGS Weekly Volcanic Activity Report
Volcano Discovery
Live Science - Volcanoes
vulkaan.startpagina.nl


Foto's
2018: The volcanic year in pictures

Actuele vulkaantopics in WKN
Aardbevingen en uitbarsting Etna
Uitbarstingen op Hawaii - Kilauea
Aardbevingszwerm bij Santorini
Centrale topic over de IJslandse vulkanen
Activiteit bij Mayotte neemt toe
Honderden doden bij uitbarsting Krakatau
Campi Flegrei - Supervulkaan bij Napels

Archief en Verzameltopics
Reeks: Vulkanen op Fok!
Krakatoa
Etna
Supervulkaan Yellowstone
Uitbarsting Merapi 2010
Mount St.Helens
Uitbarsting El Hierro Canarische Eilanden
Vulkaanuitbarsting Chili
Tungaruhua Ecuador
Vulkanen op IJsland

Interessante Twitter-accounts van Vulkanologen
https://twitter.com/johnseach
https://twitter.com/volcanologist
https://twitter.com/janinekrippner
https://twitter.com/kenhrubin
  Moderator vrijdag 1 maart 2019 @ 11:33:00 #2
8781 crew  Frutsel
pi_185316992
quote:
These ice-covered Chilean volcanoes could erupt soon

Stretching over 4,350 miles (7,000 km) across seven countries, the Andes are the world’s longest mountain range. They make up the southeastern portion of the Ring of Fire and are well-known for their abundant volcanoes.

The Chilean Andes are home to 90 active volcanoes, all monitored by the Chilean National Geology and Mining Service (Sernageomin). The agency categorizes volcanic activity using four distinct alert levels: green (normal level of activity), yellow (increased level of activity), orange (probable development of an eruption in the short term), and red (eruption is ongoing or imminent). Increased volcanic activity is associated with frequent earthquakes; plumes of gas, rocks, or ash; and lava flows.

Two areas monitored by Sernageomin are currently showing signs of increased activity: the Nevados de Chill醤 and Planch髇-Peteroa volcanic complexes. The agency issued orange and yellow alert levels for them, respectively.

Nevados de Chill醤 Volcanoes: Orange Alert

The Nevados de Chill醤 volcano complex is composed of several glacier-covered volcanic peaks. When these volcanoes erupt, the glacial ice sitting atop them melts and mixes with lava, which can result in dangerous lahars, or mudflows. Several small earthquakes and the formation of new gas vents led Sernageomin to issue a yellow alert on December 31, 2015.

On April 5, 2018, Sernageomin upgraded the Nevados de Chill醤’s yellow alert to an orange alert, following thousands of tremors and a thick, white column of smoke rising from the area. This signaled the likelihood of an eruption in the near future.

Sernageomin’s most recent volcanic activity report for Nevados de Chill醤, issued on February 11, 2019, cited persistent seismic activity, which is directly related to increased frequency of explosions, along with the growth and/or destruction of the lava dome that lies in the crater. The expected eruption is most likely to have moderate to low explosive power, but sporadic observations over the last year have shown higher-than-average energy levels.

On February 15, 2019, the Volcanic Ash Advisory Center in Buenos Aires documented a volcanic-ash plume reaching 12,139 feet (3,700 meters) high at Nevados de Chill醤, an example of the above mentioned “higher than average energy levels.”

Bottom line: Recent increased volcanic activity in the Nevados de Chill醤 prompted Chilean authorities to issue an orange alert in anticipation of an eruption.
  Moderator / Redactie Sport / Weblog vrijdag 1 maart 2019 @ 13:33:17 #3
17650 crew  rubbereend
JUICHEN
pi_185319059
_O_ voor deze reeks
DeLuna vindt me dik ;(
Op zondag 22 juni 2014 12:30 schreef 3rdRock het volgende:
pas als jullie gaan trouwen. nu ben je gewoon die Oom Rubber die met onze mama leuke dingen doet :)
  Moderator woensdag 20 maart 2019 @ 11:53:16 #4
8781 crew  Frutsel
pi_185734613
registreer om deze reclame te verbergen
quote:
Explosion at Mexico's Popocatepetl volcano hurls hot rock, ash

MEXICO CITY -- An explosion at the crater of Mexico's Popocatepetl stratovolcano has hurled incandescent rock about 1 1/2 mile down its slopes and sent ash into the night sky near the nation's capital.

The Mexican government disaster agency says ash was expected to fall on towns near the crater following the outburst at 9:38 p.m. Monday.

The 17,797-foot volcano has been particularly active in recent months, several times spewing out sprays of hot rock and towering clouds of ash

Some 25 million people live within about 60 miles of the mountain's crater.

pi_185908558
nrc twitterde op donderdag 28-03-2019 om 18:45:08 Inwoners van omliggende dorpen bij de #Popocat閜etl in #Mexico zijn gewaarschuwd: de #vulkaan spuwt as en rook.https://t.co/9Zp4n3kbQY reageer retweet
  Moderator vrijdag 29 maart 2019 @ 08:36:03 #6
8781 crew  Frutsel
  Moderator maandag 1 april 2019 @ 09:48:46 #7
8781 crew  Frutsel
pi_185965604
registreer om deze reclame te verbergen
quote:
Increased activity at Taal volcano, alert level raised, Philippines

The Philippine Institute of Volcanology and Seismology has raised the alert status of Taal volcano from Alert Level 0 to Alert Level 1 (abnormal) on March 28, 2019. The last eruption of this volcano took place in 1977. Powerful pyroclastic flows and surges from historical eruptions have caused many fatalities.

There has been a recent change in the condition of Taal Volcano based on the following observed changes in monitoring parameters:

Volcanic Earthquake Activity: A total of 50 volcanic earthquakes have been recorded by Taal Volcano’s seismic monitoring network since March 22, 2019. This recent earthquake swarm may indicate rock-fracturing beneath the edifice possibly associated with hydrothermal activity. Prior to this, the frequency of volcanic earthquakes was on average within the baseline levels (0-5 events/day) since 2016.
Ground Deformation: Cumulative elevation changes of the volcanic edifice based on precise leveling (PL) measurements this March 2019 indicate that it has slightly inflated relative to November 2018 after a period of general deflation since 2016. Slight inflation of the edifice starting in January 2019 was also recorded by continuous Global Positioning Systems (GPS) after a period of general deflation since 2016.
Gas Emission: Dissolved carbon dioxide (CO2) concentrations in Taal Main Crater Lake (MCL) based on continuous measurements have been gradually increasing since February 2019, indicating a slight increase in the input of volcanic CO2 degassing from the hydrothermal system into the lake.
In view of the above, DOST-PHIVOLCS has raised the alert status of Taal from Alert Level 0 to Alert Level 1. This means that the volcano is at an abnormal condition.

The public is reminded that the Main Crater should be strictly off-limits because sudden steam explosions can occur and high concentrations of lethal volcanic gases can be released.

The northern portion of the Main Crater rim, in the vicinity of Daang Kastila Trail, can also become hazardous when fumarolic or degassing activity along existing fissures suddenly increases.

Furthermore, the public is also reminded that the entire Volcano Island is a Permanent Danger Zone (PDZ), and permanent settlement in the island is strongly not recommended.

Taal Volcano’s seismic monitoring network recorded 3 volcanic earthquakes during the past 24 hours, PHIVOLCS reported 00:00 UTC (08:00 LT), March 29.

Field measurements on March 28, 2019 at the eastern sector of the Main Crater Lake yielded an increase in water temperature from 30.7 癈 to 31.7 癈 (87.2 - 89 癋), a decrease in water level from 0.46 m to 0.41 m (1.5 to 1.3 feet) and increase in acidity from pH 2.95 to pH 2.67.

Ground deformation measurements through precise leveling surveys from March 18 to 27, 2019 indicated slight inflation of the edifice consistent with recent results from continuous GPS data.
  Moderator woensdag 10 april 2019 @ 21:26:27 #8
8781 crew  Frutsel
pi_186145390
quote:
Increased seismicity and temperature at Te Wai ā-moe, Mount Ruapehu, New Zealand
GNS Science volcanologists are reporting another phase of high lake temperatures at Te Wai ā-moe (Crater Lake), Mount Ruapehu along with moderate levels of volcanic tremor. The Volcanic Alert Level remains at 1.

GeoNet is continuously recording the temperature of Te Wai ā-moe since 2009. Over this time, the temperature has often cycled between ~ 15 and 45 癈 (59 - 113 癋) over a period of about 12 months.

However, in September 2018 they recorded a departure from this, and for the following 6 months the lake temperature remained elevated (at ~ 30 癈 / 86 癋).

Over the last two weeks, the lake temperature has risen further, at a rate of around 0.5 癈 (0.9 癋) per day, to 42 癈 (107.6 癋) on April 9. To put this in context, only 1% of post-2009 temperatures have exceeded 42 癈 and a similar temperature last occurred in May 2016.

The level of volcanic tremor typically also increases when the lake temperature rises, and this has been the case in the last 2 weeks. The current tremor intensity is moderate. In previous heating cycles, this increased tremor lasted for a few days to several weeks.

In the past, eruptions at Ruapehu have occurred more often when the lake exceeded 45 癈 (113 癋). However, a temperature of 46 癈 (114.8 癋) was recorded in 2016 with no eruption.

While Volcanic Alert Level remains at one, which is a minor unrest, 'it is a useful reminder that eruptions can occur with little or no warning,' Duty Volcanologist Agnes Mazot said. GNS Science continues to closely monitor Mt Ruapehu and the country's other active volcanoes.

The last eruption of this volcano took place on September 25, 2007 - Volcanic Explosivity Index of 3. Its last major eruptive phase started on June 16, 1996, and lasted until September 1 of the same year (VEI 3).
pi_186161476
Een mooi animatiefilmpje over de uitbarsting van Anak Krakatoa en de daarop volgende tsunami van 22 december j.l.
Bij Hoevelaken linksaf
  Moderator donderdag 18 april 2019 @ 11:26:37 #10
8781 crew  Frutsel
pi_186291099
quote:
Increased seismicity and ground-deformation at Mauna Loa Hawaii
Activity at Hawaiian Mauna Loa volcano has risen to levels comparable to a higher period of activity between 2014 and 2017, HVO scientists said. The last eruption at the volcano took place in 1984.

While there is no cause for alarm, those signs of higher activity include increased earthquakes and ground deformation around the volcano's summit, HVO scientist-in-charge Tina Neal said, as reported by the Hawaiian Tribune-Herald.

The volcano has experienced up to 90 earthquakes a week since August, although most of the quakes have been mild, measuring 2.0 or less on the Richter scale, she said, adding that earthquakes on Mauna Loa dropped to less than five a week around early 2018.

Deformation rates appear similar to how they were in the volcano's more active period starting in 2014, but are not as high as the highest deformation during that time, when some parts of the volcano measured approximately 5 cm (1.9 inches) in a year.

The increased activity comes shortly after the cessation of significant volcanic activity at Kilauea whose eruption last year also began shortly after a decrease in activity at Mauna Loa.

While there is some geological basis to suggest a correlative pattern, this new activity will test the hypothesis.

"An eruption could be anywhere from months to years away," Neal said. "But we do know that it’s not days or weeks away."

Mauna Loa has not erupted with the frequency of Kilauea in recent years, but its 33 historical eruptions have, on average, generated much larger volumes of lava on a daily basis. Lava flows on Mauna Loa tend to travel much longer distances in a shorter period of time than those on Kilauea. Thus, warnings and notifications in the first few hours of an eruption are critical for public security.
  Moderator dinsdag 21 mei 2019 @ 13:20:28 #11
8781 crew  Frutsel
pi_187002378
quote:
Alert level raised for Japanese Hakoneyama volcano
The Japan Meteorological Agency (JMA) raised Alert Level for Hakoneyama volcano from Level 1 to Level 2 at 17:15 UTC on May 18 (02:15 JST on May 19). The last magmatic eruptive activity at this volcano took place about 2 900 years ago. The volcano is located in Kanagawa Prefecture, south of capital Tokyo.

JMA said the number of volcanic earthquakes has increased since the morning of May 18 (LT), along with fumarolic activity in Owakudani and the surrounding areas.

Large volcanic rocks could fall at Owakudani, JMA said, prohibiting access to the popular tourist spot.

According to The Asahi Shimbun, Hakone Ropeway Co. suspended operations between Sounzan and Togendai stations, the starting to final stops, and started to provide bus service between these stations.

A phreatic explosion about 3 000 years ago was followed by the collapse of the NW side of Kamiyama, damming the Hayakawa valley and creating Lake Ashi. The latest magmatic eruptive activity about 2 900 years ago produced a pyroclastic flow and a lava dome in the explosion crater, although phreatic eruptions took place as recently as the 12 - 13th centuries CE.

Seismic swarms have occurred during the 20th century. Lake Ashi, along with the thermal areas in the caldera, is a popular resort destination SW of Tokyo. (GVP)
  Moderator vrijdag 7 juni 2019 @ 13:40:05 #12
8781 crew  Frutsel
pi_187304931
quote:
Sleeping giant: Scientists warn Russian volcano could cause destruction on scale of Pompeii

A slumbering titan in Russia’s Far East could soon awaken. Scientists warn that a long-dormant volcano is showing new signs of activity, and an eruption could spell disaster in Russia and beyond.
Deemed inactive for decades, the Bolshaya Udina volcano has come back to life, according to recent research, prompting concern about a potentially cataclysmic natural disaster.

“When a volcano is silent for a long time, its first explosion can be catastrophic,” said Ivan Kulakov, the head of the seismic tomography lab at the Russian Institute of Petroleum Geology and Geophysics, in an article for the Russian Academy of Sciences’ Siberian branch. “A large amount of ash is thrown into the air, it is carried far away, and not only the surrounding settlements, but also large territories all over the planet, can suffer.”

“Recall Pompeii,” the researcher added ominously: the ancient Roman settlement was wiped off the map by the eruption of Mount Vesuvius, which laid dormant for thousands of years prior. The city was buried in over 10 feet of ash and most of its inhabitants are thought to have been killed in the disaster.

Kulakov headed up a study in 2017 to measure what he called “seismic unrest” around Bolshaya Udina; his team’s findings led to a reclassification of the volcano from ‘extinct’ to ‘active’ the same year.

While the researchers warned of the volcano’s huge destructive potential, it may be too early to begin preparing for the apocalypse. It is impossible to predict whether an eruption would occur, Kulakov said, but added “undoubtedly, now we need to closely monitor Udina.”
  zondag 9 juni 2019 @ 17:34:05 #13
11839 DemonRage
[ Eindhoven ]
  Moderator dinsdag 11 juni 2019 @ 08:37:14 #14
8781 crew  Frutsel
  vrijdag 14 juni 2019 @ 23:53:31 #15
11839 DemonRage
[ Eindhoven ]
pi_187428503
Blijkbaar heeft Popocat閜etl in Mexico een aswolk uitgespuugd van 5 km hoog.
https://www.contrareplica(...)con-fumarola20191461 (helaas niet Engels of Nederlands)
  dinsdag 18 juni 2019 @ 08:23:58 #16
15559 bwt
VvvrOOoeeeMmmmm
pi_187480672
teideano twitterde op zaterdag 15-06-2019 om 10:25:57 Huge outburst of LP events at Teide volcano yesterday. +500 events, including the most energetic LP ever registered by our Network. @eruptionsblog @GeoTenerife @janinekrippner https://t.co/Gv6qxwhV6v reageer retweet
<a href="http://goo.gl/q8fhTe" target="_blank">FAQ?</a>
<a href="http://goo.gl/gYvZFq" target="_blank">Geel is een zonnige en vrolijke kleur, als hij tenminste enigszins warm is gekleurd en wat naar het oranje neigt</a>
  Moderator dinsdag 18 juni 2019 @ 08:51:40 #17
8781 crew  Frutsel
pi_187480842
quote:
Meer dan 500 kleine aardbevingen bij Canarische Eilanden in twee uur tijd
SANTA CRUZ DE TENERIFE - Op vrijdag zijn er in twee uur tijd meer dan 500 kleine aardbevingen gemeten op het Canarische eiland Tenerife. Dit meldt het lokale geografische instituut Involc醤.

De reeks bevingen, ook 'seismische zwerm' genoemd, werd geregistreerd tussen 5:10 en 6:50 uur lokale tijd op vrijdagmorgenop een diepte van 10 kilometer onder de vulkaan Pico del Teide, tevens de hoogste berg van Spanje. De zwaarste beving had een magnitude van 1,8 op de Schaal van Richter. Volgens Involc醤 gaat het om een van de grotere beving-reeksen sinds het Red S韘mica Canaria in november 2016 werd geopend.

Bij de alarmdiensten zijn geen meldingen van schade binnengekomen. Het gaat om de grootste reeks kleine aardbevingen in korte tijd sinds er meer dan 700 werden geregistreerd op 2 oktober 2016. Involc醤 schrijft de bevingen toe aan een 'mogelijke injectie van magmatische vloeistoffen' in het Teide-systeem. Een proces dat typisch is voor een actief vulkanisch systeem.
  Moderator donderdag 20 juni 2019 @ 09:03:04 #18
8781 crew  Frutsel
pi_187515846
quote:
Is a long-dormant Russian volcano waking up? It’s complicated

Seismic rumbles beneath a long-dormant volcano on Russia’s Kamchatka Peninsula could herald an imminent eruption, a team of scientists says. But other researchers say that the observed seismic activity could be related to already erupting volcanoes in the region.

Fewer than 10,500 people live within 100 kilometers of the volcano, called Bolshaya Udina, making a catastrophic eruption that would affect large numbers of people extremely unlikely. When the volcano last erupted is unknown, but it hasn’t for at least 10,000 years, so many volcanologists consider it no longer active, or “extinct.” But Kamchatka is home to numerous active volcanoes, including nearby Bezymianny, which most recently erupted March 15.

Scientists had detected an apparent increase in seismic activity in the vicinity of Bolshaya Udina beginning in late 2017. So researchers, led by geophysicist Ivan Koulakov of the A.A. Trofimuk Institute of Petroleum Geology and Geophysics in Novosibirsk, Russia, installed four temporary seismic stations near the volcano. From May 5 to July 13, 2018, the stations recorded a swarm of 559 earthquakes.

Overall, from October 2017 through February 2019, researchers detected about 2,400 seismic events, the strongest of which was a magnitude 4.3 earthquake in February. Previous to that 16-month period, scientists detected only about 100 weak seismic events in the region from 1999 to 2017.

Furthermore, by examining how some of the seismic waves decreased in velocity as they traveled through the subsurface, the team found evidence that there might be a pocket of fluid — perhaps magma — directly beneath Bolshaya Udina.

The dramatic uptick in activity, along with the possible detection of magma, could mean that Bolshaya Udina is waking up, the team reports in the July 15 Journal of Volcanology and Geothermal Research.

Other scientists are not so convinced, noting that the data could be interpreted in other ways. Seismicity may indicate the movement of magma, but the volcanic plumbing beneath Kamchatka’s volcanoes is complex, and Bolshaya Udina may not be the ultimate destination.

Volcanologist Olga Girina of the Institute of Volcanology and Seismology in Petropavlovsk-Kamchatsky, Russia, says the new study’s data are good. But she questions the researchers’ interpretation that the seismic activity is related to Bolshaya Udina. Girina, who is part of the Kamchatka Volcanic Eruption Response Team, suspects that the 2018 swarm of earthquakes could instead have been leading up to the Bezymianny eruption in March. There have been no swarms detected since that eruption, she says.
  Moderator woensdag 26 juni 2019 @ 09:07:57 #19
8781 crew  Frutsel
pi_187612380
quote:
Vulkaan spuwt as kilometers hoog de lucht in

PORT MORESBY - De vulkaan Mount Ulawun in Papoea-Nieuw-Guinea spuwde woensdag as kilometers hoog de lucht in. De autoriteiten waarschuwen voor een mogelijke uitbarsting. Bewoners aan de voet van de vulkaan zijn ge雟acueerd.

Mount Ulawun ligt op een eiland in de afgelegen Bismarck-archipel en geldt als een van de gevaarlijkste ter wereld, omdat ze een aanzienlijk risico vormt op grote, gewelddadige uitbarstingen.

Duizenden mensen leven in de schaduw van Ulawun, ondanks dat het een van de meest actieve vulkanen in het land is.
  Moderator zondag 30 juni 2019 @ 12:30:22 #20
8781 crew  Frutsel
pi_187677981
quote:
15.000 mensen gevlucht na vulkaanuitbarstingen Papoea-Nieuw-Guinea

Vijftienduizend mensen in Papoea-Nieuw-Guinea moesten hun huizen ontvluchten door twee vulkaanuitbarstingen afgelopen week, melden hulporganisaties het Rode Kruis en de Rode Halvemaan. Zover bekend zijn er geen doden gevallen, maar huizen, akkers en waterputten zijn vernield. Door de as is het luchtverkeer gestremd.

Woensdag barstte de Ulawun-vulkaan uit op het eiland Nieuw-Brittanni, ten westen van Nieuw-Guinea, en schoot as 18 kilometer hoog de lucht in. Op vrijdag barstte dicht bij de kust van het eiland de Manam-vulkaan uit, die gevaarlijke gloedwolken uitspuwde. Manam zou voorlopig nog door kunnen gaan met lava uitstoten, dat de zee in zal stromen.

Door de Manam-uitbarsting sloegen 3.775 mensen op de vlucht en 11.047 mensen moesten hun huizen verlaten door de Ulawun-vulkaan. Veel mensen zijn opgevangen in opvangcentra.

De omgevingen van de vulkanen zijn bedekt in vulkanische as, dat dodelijke gevolgen kan hebben als deze wordt ingeademd. Hierdoor kunnen mensen nog niet terug naar hun woningen. Als regen niet snel de as wegspoelt, kunnen gewassen worden beschadigd.

Het Rode Kruis, provinciale overheden, rampencentra en het Leger des Heils brengen noodvoorraden naar de opvangcentra, meldt het Rode Kruis op Papoea-Nieuw-Guinea. De minister-president van het land, James Marape, gaf aan het nationale leger in te willen zetten om te helpen.
  Moderator woensdag 3 juli 2019 @ 15:52:17 #21
8781 crew  Frutsel
pi_187732521
quote:
Mauna Loa volcano (Hawai'i) activity update: alert level raised to yellow due to increase in seismic activity

The alert level for the volcano has been raised to yellow two days ago. This doesn't mean that an eruption is expected to occur in a near future, but acknowledges that the volcano is currently preparing itself for its next eruption, which will come, sooner or later, but currently without possibility to indicate a specific time frame.
The Hawaiian Volcano Observatory (HVO) reported that "for the past several months, earthquake and ground deformation rates at Mauna Loa Volcano have exceeded long term background levels. An eruption is not imminent and current rates are not cause for alarm. However, they do indicate changes in the shallow magma storage system at Mauna Loa."

"Following a significant earthquake swarm in October 2018, HVO seismic stations have recorded an average of at least 50 shallow, small-magnitude earthquakes per week beneath Mauna Loa's summit, upper Southwest Rift Zone, and upper west flank. This compares to a rate of fewer than 20 per week in the first half of 2018. Shallow earthquakes are occurring in locations similar to those that preceded Mauna Loa's most recent eruptions in 1975 and 1984.

"During this same time period, GPS instrumentation and satellite radar have measured ground deformation consistent with renewed recharge of the volcano's shallow magma storage system. The current rate and pattern of ground deformation is similar to that measured during inflation of Mauna Loa in 2005 and again from 2014 - 2018.

"Together, these observations indicate the volcano is no longer at a background level of activity. Accordingly, HVO is elevating the Mauna Loa alert level to ADVISORY and the aviation color code to YELLOW." (HVO / USGS
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Tankuban Perahu barst uit:




[ Bericht 13% gewijzigd door Ener-G op 26-07-2019 13:26:04 ]
"Light thinks it travels faster than anything. It doesn't. For wherever light travels it finds darkness has got there first and is waiting for it."
  Moderator dinsdag 6 augustus 2019 @ 16:11:52 #23
8781 crew  Frutsel
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quote:
6 Underwater volcanoes discovered near Sicily
Scientists have discovered a series of previously unknown volcanoes just off the coast of SW Sicily, Italy. The three northern volcanoes show a tuff cone-like morphology while the three most southern edifices have a truncated-conical shape. Ages of all newly discovered volcanoes are Late Quaternary. Only the northernmost volcano shows indications of a post-Last Glacial Maximum magmatic reactivation.

The Graham and Terrible banks, located about 35 km (21 miles) from the south-western coast of Sicily, host a large number of volcanic constructs, the most famous being the ephemeral Ferdinandea Island, authors said in the abstract of the new study, published recently in Elsevier's Marine Geology.

These volcanoes occur along two N-S trending strike-slip lineaments that constitute the lithospheric-scale Capo Granitola-Sciacca Fault Zone.

In the study, the researches presented recently acquired swath bathymetric data and magnetic measurements, in conjunction with high-resolution seismic profiles, which reveal the presence of another six volcanic edifices located very close to the Sicilian coasts, one of which is only 7 km (4.3 miles) away.

3 of these volcanic constructs have been previously identified only on the basis of available seismic profiles, but their morphology and their volcanic nature had so far not been documented. 2 edifices to the north show a possible tuff cone/ring-like morphology modified by crater breaching, while the three southernmost volcanoes have a truncated-conical shape.

The northwestern-most volcano (here called Actea) shows a more complex morphology, probably representing the remnants of a previous crater rim.

Seismic data analysis suggests that the six volcanic edifices were generated during a pre-Last Glacial Maximum (ca. 20 000 B.P.) magmatic phase associated with a tectonic event.

Only the Actea volcano shows indications of magmatic reactivation, possibly between the LGM and the initial post-LGM transgressive phase. This reactivation is evident by the emplacement of a prominent young lava flow.

The discovery of submerged volcanoes so close to the populated coast of Sicily demonstrates that there are large submerged areas near the littoral that are still little known and studied, and underlines how crucial it is to analyze the issue of volcanic risk for densely inhabited coastal areas like Sicily.
fbg64iG.jpg
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Volcano near Tokyo erupts, prompting warnings

TOKYO: A volcano near Tokyo has erupted for the first time in four years, throwing ash and smoke nearly 2km into the sky and sparking warnings not to approach the mountain.

Mount Asama, about 140km northwest of the Japanese capital, exploded overnight and prompted the national meteorological agency to raise its alert level to three out of five, meaning people should avoid the crater.

The agency warned that large rocks and fast-moving flows of hot gas could affect a radius of 4km from the crater and that nearby towns could be hit by smaller rocks and ash depending on prevailing winds.

An agency official told AFP on Thursday (Aug 8) that gas was still being thrown into the air but at a "normal" level.

"We don't see activity picking up," he said.

Mount Asama last erupted in June 2015. There were no injuries in the small eruption
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Tankuban Perahu weer:

Deze zijn nog van twee weken geleden, de tweede had ik nog niet gezien.. scary stuff op :50 en daarna als de aswolk omlaag komt, lekker in de gloeiend hete asdeeltjes (in feite fijnstof glas deeltjes wat je daar in staat te ademen) :X


Eergisteren:



[ Bericht 31% gewijzigd door Ener-G op 20-08-2019 11:40:19 ]
"Light thinks it travels faster than anything. It doesn't. For wherever light travels it finds darkness has got there first and is waiting for it."
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[ Bericht 99% gewijzigd door Houtenbeen op 26-08-2019 14:01:02 ]
  donderdag 29 augustus 2019 @ 08:12:02 #28
94257 aloa
Steeds harder, steeds sneller
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Strombolian activity, high levels of volcanic tremor at Etna, Italy

Strombolian activity is still taking place at Etna's Northeast Crater, producing a diluted ash plume that disperses near the summit area, INGV reports. The volcanic tremor amplitude remains high.

After 08:50 UTC on September 9, 2019, there has been a further increase in volcanic tremors compared to what has been previously observed and reported.

The source is localized at the Northeast Crater at about 3 000 m (9 842 feet) elevation, and also the origin of infrasonic signals coincides with the same crater.

Modest variations are recorded by the clinometric network, particularly at the Punta Lucia and Pizzi Deneri stations (which are at 2 900 m / 9 514 feet and 2800 m / 9 186 feet to the NW and NE of the summit, respectively).

The tilt signal shows a "noise" typically associated with strong volcanic tremor. No significant variations are evident from GPS data.

The SO2 flux measured by the FLAME network indicates a mean daily value of 4 800 tons per day as of 15:25 UTC, placing the degassing at an average level and below the threshold of attention - 5 000 tons per day.

Infra-daily recordings have shown maximum values of up to 11 650 tons per day, corresponding to degassing at a high level.

NGV reported an increasing trend of volcanic tremor on September 6.

"Since the second half of August, a slow and gradual rise of the mean amplitude has been recorded, which today, on the peripheric stations of the seismic network, has reached values comparable to those seen shortly before the December 2018 eruption, and higher than those observed before the eruptive episodes of May - July 2019," the institute said in a statement.

At the time, the volcanic tremor source has remained confined to the summit area, mainly below the Southeast Crater - New Southeast Crater system.

Inclement weather prevented observation of the activity at the summit craters with the visual and thermal surveillance cameras. However, mountain guides reported that sounds characteristic of Strombolian activity and spattering have been heard this morning at the Bocca Nuova crater.

The photo below shows conspicuous degassing from Etna's summit craters at daybreak on September 6, 2019, seen from the south.
  Moderator / Redactie Sport / Weblog dinsdag 10 september 2019 @ 11:12:13 #31
17650 crew  rubbereend
JUICHEN
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quote:
prachtige beelden
DeLuna vindt me dik ;(
Op zondag 22 juni 2014 12:30 schreef 3rdRock het volgende:
pas als jullie gaan trouwen. nu ben je gewoon die Oom Rubber die met onze mama leuke dingen doet :)
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Villarrica volcano Alert Level raised to Orange for the first time since 2015, Chile

Sernageomin has raised the Alert Level for Villarrica volcano to Orange on September 9, 2019 and shared evacuation maps showing different meeting points for each nearby community before a possible eruption. The last major eruption at Villarica took place in 2015.

The decision to raise the alerd was made due to increased seismicity and a more turbulent lava lake.

An exclusion zone of 2 km (1.2 miles) around the crater was put in place.

Seismicity under the volcano started increasing at 03:30 UTC on September 8, with 40 LP events per hour. While meteorological clouds prevented direct observation of the crater, other signals registered by 13:30 UTC suggested the presence of lava near the surface and minor explosions around the crater.

Sernageomin said September 9 there is a high probability that volcanic material can be ejected up to 2 km (1.2 miles) around the crater, more than was recorded in July 2019 when they reached up to 200 m (656 feet) from the edge of the crater.

Officials are considering a scenario similar to the eruption of 2015 - an explosive eruptive process of moderate magnitude, associated with untimely increase in the activity. In this condition, occurrence of explosions of greater energy and volume, in which fragments could accumulate around the crater, is possible. Low to moderate volume lahars are also expected in rivers and / or streams around the volcano.

Clouds are still preventing direct observation of the crater on September 10.

The current situation could evolve into a major eruptive event or end with no eruption at all, Sernageomin said.
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