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

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More emissions from Mexican volcano
The Popocatepetl volcano registered 14 exhalations of low intensity accompanied by water vapor, gas and a low amplitude spasmodic tremor, reported the National Center for Disaster Prevention (Cenapred). In its latest report, the agency of the Ministry of the Interior (Interior Ministry) explained that the exhalations of greater intensity occurred yesterday 13:30 and 22:42 hours. He said that although during the night, a glow was observed in the crater, the other metrics do not show major changes, so the light status of volcanic alert remains at yellow stage two. Observers should expect more moderate exhalations, some with ash emissions, sporadic explosions are also likely to issue short incandescent fragments and slight glow in the crater can also be observed at night.

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Mexican quake may have triggered San Salvador volcano activity
The Mexican 7.4 magnitude earthquake near Acapulco on Tuesday might have affected the currently dormant San Salvador volcano in 1000 km distance and triggered an earthquake swarm under the volcano.

San Salvador volcano is an active stratovolcano immediately northwest of the capital San Salvador City and last erupted in 1917.

The National Service of Territorial Studies (SNET) reported that as of yesterday 21 March 05:30 pm local time, the swarm consisted of 25 quakes, including 8 felt quakes between magnitude 2.2 and 3.3. The quakes were located at shallow depths between 0.5 and 5.8 km under the volcano.
The Red Cross is reported to have sent some members to the volcano area as a precautionary measure, although there were no reports of casualties or damage.

It is possible that the strong Mexican earthquake was the trigger for this swarm as a result of tectonic disturbance of the magma chamber beneath the volcano. Relationships between large earthquakes and volcanic eruptions with effects occurring up to a year after the quake have long been suggested, but are difficult to proof.

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Vulkanen actiever bij volle maan
Italiaans onderzoek van de Stromboli heeft geleerd dat vulkanen actiever zijn bij Volle Maan. Dat meldt de website Geopersdienst.nl.

Aardwetenschappers Gianluca Sottili, van het Istituto di Geologica Ambientale e Geoingegneria in Rome, en Danilo Palladino, van de Sapienza-Universiteit in Rome, analyseerden de explosies die zich voordeden in de krater van de Stromboli van juni 2010 tot oktober 2011.

Eén uitbarsting per vijf minuten
De Stromboli bevindt zich even ten noordoosten van het eiland Sicilië in Italië, en is al minstens tweeduizend jaar continu actief. Gemiddeld eens per vijf minuten vindt er een uitbarsting plaats, aldus de website.

De onderzoekers concludeerden dat het aantal explosies per uur bij Volle of Nieuwe Maan significant hoger ligt dan het gemiddelde voor de hele maand. Maar bij springtij is er lang niet altijd een groter aantal per uur. In sommige maanden was de activiteit dan zelfs het laagst.

Ook uit eerdere onderzoeken aan andere types vulkanen blijkt dat de stand van onze natuurlijke satelliet de kans op een uitbarsting kan beïnvloeden. Hoe dat precies in zijn werk gaat is nog niet duidelijk.

Aantrekkingskracht van de Maan
De Italiaanse aardwetenschappers denken dat het gaat om de aanvoer van magma vanuit de relatief ondiepe magmakamer. Omdat het gesteente rondom het gangenstelsel waarin de magma zit door de aantrekkingskracht van de Maan elke veertien dagen een klein beetje wordt samengedrukt en weer uitzet, zal de magmatoevoer dezelfde regelmaat vertonen - en daarmee ook de frequentie van de uitbarstingen.

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Nevado del Ruiz seems to be getting closer to a new eruption.

INGEOMINAS reports that during the last week, there has been a significant increase in the activity of the volcano, which can be summarized as follows:

- From March 27, there have been phases of volcanic tremor pulses related probably to deep magma movements

- Since the last week, there were seismic signals interpreted with rock fracturing, i.e. dike intrusions, located west of the active crater. Similar seismic activity was observed prior to the eruptions in November 1985 and September 1989, although this time it is less energetic.

- On March 29 at 10:54 local time, for a period of 25 minutes, there were over 135 earthquakes located south of Arenas crater at a depth of about 4 km.
- From 04:00 am local time on 31 March, there has been a significant increase in seismicity of events associated with fluid movements and fracturing of rock located in the active crater.
- SO2 emissions continue at high levels.

According to the diagnosis made so far, INGEOMINAS expects an eruption in the coming weeks, but smaller in size than those in November 1985 and September 1989.

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Dangerous Colombian volcano may erupt soon
Colombia's snowcapped Nevado del Ruiz volcano has lately shown signs pointing towards an immanent eruption.

An "Orange" alert has been posted, meaning that the volcano could erupt within days to weeks, the Smithsonian/USGS Weekly Volcanic Activity Report web page said on Thursday.

The Andean volcano's last important eruptions happened in 1985 and 1989, the 1985 eruption having led to Colombia's worst natural disaster.

During the last week of March, tremors shook the volcano with increasing, according to the Colombian government agency, INGEOMINAS. Volcanologists interpreted the quakes as telltales for "rock fracturing" and "fluid movement" within the volcano.

Seismicity remained "elevated" during the first days of April, the report said.

According to the Smithsonian website, Nevado del Ruiz is spread over more than 200 square km (about 80 square miles) in central Colombia.

Standing more than 17,000 feet above sea level, the highest reaches of the volcano are clad in permanent snow and ice, the near-equatorial location notwithstanding.

The conflict between hot lava and ice on Nevado del Ruiz has proven deadly in the past.

During the November 1985 eruption, melting of the ice cap generated lahars, volcanic mudflows, which swept down the mountain's six main river valleys, the Wikipedia Nevado del Ruiz web page said.

A lahar following the Lagunilla Valley swept through the town of Armero, killing three-fourths of its 28,700 residents. In all, more than 23,000 people were killed and about 5,000 more were injured, according to Wikipedia.

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Alert level raised for 'Popo'
MEXICO CITY, April 17 (UPI) -- Mexico Tuesday advised residents of Puebla state to take further precautions as the Popocatepetl volcano continued to show ominous signs of life.

A Yellow Level 3 alert was posted for the area around the volcano Tuesday, meaning there was a intermediate or high probability of a violent eruption, which would range from an ash cloud to a possible explosion.

Schools were shut down in the area and residents were advised to stay inside and keep their windows closed to keep out the moderate amounts of ash that have been escaping from the mountain, CNN said.

Puebla state officials earlier evacuated a 7-kilometer (4.3 mile) perimeter around the mountain.

Scientists monitoring the volcano said Tuesday they saw glowing lava inside the crater overnight and recorded a 40-minute tremor.

Popocatepetl, known as Popo, is located not far from Mexico City and has not experienced a major eruption since 2000.

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This is pretty interesting news – the NASA Aqua satellite spotted an eruption going on at Mt. Curry* in the South Sandwich Islands. The South Sandwich Islands are located to the southeast of South America in an odd subduction zone where South America is subducting under the Sandwich microplate. Not much is known about Mt. Curry on Zavodovski Island – it is a basaltic stratovolcano (typical in island arcs) and it is thought to have last erupted in 1819, although the Global Volcanism Program lists a number of unconfirmed small eruptions as recently as 1930. These images of Curry from 2000 show that the volcano does produce minor plumes, so this could be more of a strong steam-and-ash plume than a new eruption. However, confirmation will be difficult as few people live in the South Sandwich Islands and Zavodovski Island is uninhabited, so we’ll likely be relying on remote sensing to track this eruption. This eruption has some shades of Nabro – remote, not well known and spotted by satellite first.

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Manum Island's volcano erupting

A new series of eruptions have begun on Manam Island off Madang in Papua New Guinea, with warnings to residents to take precautions.

Manum Island's volcano erupting

The volcano is one of the most active in PNG claiming several lives over the last decade.

Vents on the volcano are glowing at nights and explosions in the craters can be heard more than 15 kilometres away.

Ima Itakarai, the assistant director of the Rabaul Volcanology Observatory says it's possibility of a major explosion cannot be ruled out, but it's not imminent.

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Activity at Mt Tongariro on Northern Island of New Zealand
On Friday, I noted that GNS Science has seen an increase in volcanic seismicity at Tongariro, a volcanic complex on the southern end of the Taupo Volcanic Zone on the North Island. Tongariro itself is made of the older Tongariro proper and the younger Ngauruhoe (famously the model for Mt. Doom in the Lord of the Rings movies). The initial information was that there were over 20 small volcanic earthquakes during a few days in mid-July, much higher than the normal background seismicity. Now it seems that volcanic gas emissions from Tongariro are up as well.

The latest GNS Science report says that although Tongariro does consistently release volcanic and hydrothermal gases, volcanic gas emissions are up significantly since the last measurement. Now, these gases are likely carbon dioxide and sulfur dioxide (the typical gases measured for monitoring), which are not hazardous to people in low concentrations (only rarely does CO2 reach levels that can kill in volcanic settings). Even with these increases in volcanic gases, GNS Science has not raised the alert status beyond Level 1 (above typical background).

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Op maandag 6 augustus 2012 17:22 schreef mouzzer het volgende:

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Dit is weer een andere, White Volcano is volgens mij een eiland voor de kust en de Tongariro ligt in een national park midden op noordereiland. Deze uitbarsting zou bij de Te Mari Crater zijn, hier te zien op de voorgrond:

[ afbeelding ]

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Evacuaties in Nicaragua vanwege vulkaan
In het noordwesten van Nicaragua zijn ongeveer 3000 inwoners geëvacueerd, nadat een vulkaan as en gas begon uit te stoten. De autoriteiten hebben militairen naar het gebied gestuurd, maar honderden mensen waren al uit zichzelf weggegaan.

De San Cristóbal-vulkaan begon gisterochtend te rommelen, kort nadat er explosies waren gehoord. Rond de vulkaan hangt een dikke rookwolk.

De autoriteiten verwachten de komende tijd meer uitbarstingen van de vulkaan.

De San Cristóbal is een van de actiefste vulkanen van Nicaragua. De afgelopen jaren zijn er geregeld kleine erupties geweest.

Nicaragua / El volcán San Cristóbal en erupción...

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Fuego vulkaan in Guatemala ook weer actief
De vulkaan Fuego in de Midden-Amerikaanse staat Guatemala is weer actief. Aan de voet van de berg ligt de toeristische stad Antiguea, Fuego is één van de meest actieve vulkanen in de regio. Op dit moment spuugt Fuego een dikke rookpluim tot anderhalve kilometer de hoogte in.

Voorlopig is er geen gevaar voor de bewoners in de buurt, maar het luchtverkeer kan er last van ondervinden. In mei spuugde de vulkaan grote hoeveelheden as en lava uit.