quote:Scientists prepare for Lake Taupo eruption
There is only a very small chance the volcano that is now Lake Taupo will erupt, but researchers are planning for a worst case scenario in case it does.
A team of researchers is studying the volcano so better response plans can be put in place in case of a large eruption.
The Earthquake Commission said damage from the last time the volcano erupted - almost 1800 years ago - would be large enough to destroy the central North Island.
The commission is funding research that will map out where ash and debris would travel in an eruption.
The research is led by Simon Barker from Auckland University. He said it will help emergency services in a worst case scenario, although the chances of a large eruption are very slight.
"We want to see what the thickness of ash will be in the various regions, how far it will go. The chances are still very very low but from the past activity we can really see quite big eruptions all the way down to really small 1995, 1996 Ruapehu size."
Dr Barker said the eruptions of Mt Ruapehu in 1995-6 were the minimum size expected at Lake Taupo, which could be up to a 100 times greater.
He said the researchers want to know where the ash will go in modern atmospheric conditions and in different seasons, as wind directions can shift a lot.
Taupo is a very large caldera (volcanic crater), Dr Barker said, taking up the entire northern part of the lake.
quote:Increased unrest continues at Ruapehu, Crater Lake cooling stops, New Zealand
New Zealand's Mount Ruapehu remains in a state of heightened volcanic unrest. The temperature of the summit Crater Lake has declined from 46 ░C (114.8 ░F), but the cooling has stopped and the temperature is rising again.
Recent visits to the volcano have confirmed the output of volcanic gas (carbon dioxide CO2, hydrogen sulphide H2S and sulphur dioxide SO2) remains elevated above background levels but is declining, GeoNet reports.
The lake temperature reached a high of 46 ║C on May 11 then the lake started to cool, declining to 30 ║C (86 ░F) by June 2. Since then it has risen to the current temperature of 32 ║C. Water samples have been collected from the Crater Lake for chemical analysis. Moderate to low levels of volcanic tremor continue.
The Volcanic Alert Level remains at Level 2 (moderate to heightened unrest). The Aviation Colour Code is also unchanged, at Yellow.
quote:Three Indonesian volcanoes erupt in three days
Giant clouds of ash engulfed the skies as Mount Sinabung became the third volcano to erupt in Indonesia, in the space of just three days.
Mount Rinjani on Lombok island near Bali erupted on Monday, with the Sinabung volcano on Sumatra island and Mount Gamalama in the Moluccas chain of islands following suit late yesterday.
No one has been injured but flights at two airports have been disrupted.
Mount Rinjani on Lombok island near Bali erupted on Monday, with the Sinabung volcano on Sumatra island and Mount Gamalama in the Moluccas chain of islands following suit late yesterday.
The archipelago of 250 million people is prone to earthquakes and volcanoes because it sits along the Pacific 'Ring of Fire,' a string of faults that lines the Pacific Ocean.
The eruptions darkened skies in parts of the archipelago and disrupted some flights.
Sutopo Purwo Nugroho, the spokesman for Indonesia's Disaster Mitigation Agency, said that Gamalama and Sinabung erupted late yesterday, blasting debris high into the air.
'People are advised to stay calm,' said Sutopo Purwo Nugroho, adding authorities were not yet planning evacuations.
Nugroho said farms and trees around the three volcanoes were covered in gray ash, but nearby towns and villages were not in danger.
Hot ash tumbled down the Sinabung slopes as far as 2,000 metres (6,562 feet) southward into a river.
The volcano has been put on alert its highest level since June 2015 following a significant increase in activity.
quote:Earthquakes in the Cape Verde Islands Could Signal an Explosive Eruption to Come
ape Verde Islands: Earthquakes on Brava in the Cape Verde Islands noticed on August 1 have prompted a heightened alert and evacuations of over 300 people from the slopes of the volcano. Brava has no known eruptions in the past 10,000 years, although many of the cones and flows on the volcano look relatively young. Based on its location in an oceanic island chain (like Hawai’i), you might expect lava flows from Brava. However, some of what are thought to be the most recent eruptions are phonolite, which is a stickier lava with higher silica content that can produce explosive eruptions. Combine that with interaction with groundwater on Brava, and we could see an explosive eruption.
Only two years ago, Fogo in the Cape Verde Islands had one of its most specular eruptions in decades, with lava flows that overran multiple villages.
quote:Phivolcs warns of 'big' Mayon eruption in coming days
Phivolcs cites 'abnormal activity' such as drying wells, more earthquakes, and increased sulfur dioxide emission of the volcano
LEGAZPI CITY, Philippines – The Philippine Institute of Volcanology and Seismology (Phivolcs) has warned of a possible "big" Mayon volcano eruption in the coming days.
"Phreatic explosion may happen anytime but a big explosion is expected in the coming days," said Philvolcs resident volcanologist Eduardo Laguerta.
Laguerta cited "abnormal activity" similar to what happened prior to the Mayon eruption in 1984.
The 1984 Mayon eruption is classified as a Vulcanian-type eruption which involves relatively small but violent explosions of thick lava producing columns of ash, gas, and occasional pyroclastic flows.
"The massive drying up of wells across Albay, specifically in the municipalities surrounding the volcano, may be attributed to the magma movement activity beneath the restive volcano," Laguerta added.
He also cited the 3 consecutive earthquakes in August originating from the Sto Domingo fault line, which can affect volcanic activity.
Laguerta said his office asked geodetic engineers from the Phivolcs central office to conduct a ground survey around the volcano following the earthquakes.
"We noted after the survey, Mayon is inflated, magma beneath the volcano is building up. Deep wells are drying up surrounding the volcano and in several towns here – an implication of abnormal activity," he said.
Magmatic eruption possible
Laguerta said that while magma build-up did not progress past the belly of the volcano during its explosion in 2014, a "magmatic eruption" may happen this time around.
"Today the possibility to continue for magmatic eruption is possible. We cannot discount the possibility of big explosion," he said.
With these latest findings, Phivolcs raised Mayon to Alert Level 1.
According to a Phivolcs advisory, its monitoring showed the following:
Increased sulfur dioxide emission from the Mayon crater, or beyond the baseline level of 500 tons per day, even exceeding 1,000 tons per day on some days, since July 2016
Increased volcanic earthquake activity, with a total of 146 earthquakes recorded by the Mayon Volcano Observatory seismic network from August 3 to August 6 on the southeast side, 10 kilometers away from the volcano
4 of the 14 monitored water wells located on the southeastern side of Mayon are drying up, while one has completely dried up
Steam activity from the crater has ranged from weak to moderate, and no crater glow – which would indicate magma activity – has been observed. Even so, Phivolcs warned of a phreatic explosion anytime that could lead to a big eruption.
Rocks and steam are spewed out during a phreatic explosion.
Laguerta also reiterated the government's warning for the public to stay out of the 6-kilometer danger zone, to avoid casualties.
In 1993, 77 farmers were killed, while several foreigners and their Filipino tourist guide were killed in phreatic explosions in 2013.
Cedric Daep, Albay Public Safety and Emergency Management Office (Apsemo) chief, said there are 18,000 people living along the slopes of the volcano.
hmmm..das die vulkaan die toch al spectaculaire shots oplevert....quote:Sakurajima volcano building up for major eruption
The Sakurajima volcano in Japan last erupted in 1914 killing 58 people and caused widespread flooding in the nearby city of Kagoshima.
The volcano, however, could erupt again in the next few decades as the pool of liquid magma that swells beneath it grows each year, indicating a looming large eruption.
A team of researchers developed a new method for imaging the underground plumbing system of Sakurajima, one of the most active volcanoes in Japan.
Using GPS deformation measurements and 3D computer models, the researchers assessed the buildup beneath Sakurajima volcano and found that the reservoir of magma grows at a significant rate. They found that 14 million cubic meters (494 million cubic feet) of magma accumulate every year, which is enough to fill the Wembley Stadium three-and-a-half times over.
Based on their findings, the researchers said that it would take 130 years from the volcano's last major eruption for the next one to happen. This means that the region is due for a major eruption about 2044, which is about 25 years from now.
Although the Sakurajima volcano remained constantly active over the last several decades, the small regular volcanic eruptions were not able to get rid of all the magma and the Aira caldera — deep crater that was formed from a collapsed magma chamber. It now serves as a shallow reservoir for Sakurajima's magma and is being filled faster than the rate magma is released through small eruptions. This means that pressure is building up.
"Using the example of continued inflation at Aira caldera, Japan, we demonstrate that magma is accumulating faster than it can be erupted, and the current uplift is approaching the level inferred prior to the violent 1914 Plinian eruption," the researchers reported in their study, which was published in the journal Scientific Reports on Sept. 13.
"[T]he inferred magma supply rate indicates a ~130-year timeframe to amass enough magma to feed a future 1914-sized eruption."
Although it is not possible to accurately predict when a volcano would erupt, the researchers said that the result of their study should help authorities plan for future disasters not just in Japan but also in other places worldwide.
"The numerical constraints we were able to put on the magma supply conditions can also be used to assist with probabilistic and quantitative eruption forecasting," said study researcher James Hickey, from the School of Earth Sciences at the University of Bristol in the UK.
quote:Tourists evacuated after eruption
JAKARTA: Rescuers in Indonesia were dispatched Wednesday to evacuate nearly 400 tourists, most of them foreigners, after a volcano erupted at one of the country's most popular hiking destinations, an official said.
Mount Barujani began erupting late Tuesday afternoon, sending columns of ash and smoke shooting 2 kilometres (1.2 miles) into the sky over Lombok island, a tourist hotspot to the immediate east of Bali.
Nearly 400 people were recorded as hiking near Barujani -- a smaller cone within the crater of Mount Rinjani -- when it began erupting, prompting plans for their immediate evacuation, said national disaster agency spokesman Sutopo Purwo Nugroho.
"A rescue team has been sent to Mount Rinjani to evacuate the tourists. They set off on Wednesday morning," he said.
Hikers have been told to keep at least 3 kilometres from the smouldering volcano, a key attraction on the multi-day trek to the summit of Mount Rinjani made by thousands of tourists every year.
Nugroho said 389 hikers were recorded as having entered the national park since Sunday, the overwhelming majority of them foreigners.
While most would have taken the official route to the summit, rescue teams suspected some hikers may have gone off-piste, Nugroho added.
The threat level of the volcano was upgraded Tuesday as Barujani sent plumes of smoke and hot ash into the atmosphere, but remains two steps from the highest-risk category.
There were no flight disturbances recorded on Wednesday due to the ash clouds, transport ministry spokesman Hemi Pramuraharjo told AFP.
Some flights to and from the nearby resort island of Bali were cancelled overnight, but Lombok's international airport remains unaffected.
Flight disruptions due to drifting ash clouds are not uncommon in Indonesia, which sits on a belt of seismic activity known as the Pacific Ring of Fire and is home to 130 active volcanoes.
An eruption at Mount Rinjani last month forced the closure of Lombok airport and disrupted some flights to neighbouring Bali.
quote:AVO raises alert level for Cleveland volcano to orange after explosion
October 24, 2016: The Alaska Volcano Observatory (AVO) has raised the alert level for the Cleveland volcano to orange from yellow after detecting explosion.
The explosion at Cleveland volcano was recorded at 13:10 AKDT (21:10 UTC). The explosion was heard by the residents in Nikolski, about 75 km from Cleveland volcano.
"The most recent significant period of eruption began in February, 2001 and produced 3 explosive events that generated ash clouds as high as 39,000 ft above sea level," the volcano observatory noticed stated on Monday.
According to the observatory, the orange code, the second-highest on the scale, is issued when a volcano is "exhibiting heightened or escalating unrest with increased potential of eruption."
The volcano, named after U.S. President Grover Cleveland, is located about 75 km (45 mi) west of the community of Nikolski, and 1500 km (940 mi) southwest of Anchorage.
quote:Sumatra volcano rages on
Residents in Karo regency on Sumatra island were on edge yesterday, with a rumbling Mount Sinabung spewing volcanic ash that reached as high as 1km. The volcano, which began erupting on Sunday, has prompted the authorities to bar tourists from entering a radius of 6km from the crater, volcanologist Nia Hairani said. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013. It has been highly active since. It is one of 129 active volcanos in Indonesia sitting on a quake-prone zone called the Pacific Ring of Fire.
quote:Cayambe volcano in Ecuador has become restless
The volcano has become restless. Scientists from Ecuador's Institute of Geophysics (IGEPN) recorded an increased number of earthquakes under the volcano a new report shows. The increased seismicity could be (but not must be) a precursor of renewed activity in the medium-term future (weeks, months?).
An increase of earthquakes began on 5 June this year when a seismic swarm of earthquakes started which totaled more than 2300 events by the end of the month. The quakes occurred concentrated in an area NE of the volcano and were volcano-tectonic in origin, likely caused by a magma intrusion at depth causing pressurization and fracturing of rocks.
After the June swarm, the volcano returned to calm again first. New earthquakes started to appear in increased numbers from September and have been continuing. Different from in June, the quakes have been concentrated under the summit area of the volcano and been showing an
upward trend in depth.
In addition, there have been increased reports of strong sulfur smell from climbers who visited the volcano, suggesting that there has been an increase in SO2 emission.
Both observations fit into the interpretation that a new magma body has been intruding inside the volcano. Whether or not it reaches the surface (and if so, when), i.e. causes a new eruption, is matter of speculation and cannot be answered with certainty.
For now, the signs of unrest are considered weak. They favor the idea that the intrusion of magma is of small volume only. As a consequence, if there is an eruption to come it is (for now) expected to be likely a small one only.
Cayambe's last eruption was only a moderate event in 1785-86, although the volcano has had violent explosive eruptions in the recent geologic record (i.e. past few thousands of years) and merits to be closely monitored.
Zie ookquote:120 quakes rattle Mt.St.Helens last month
Roughly 120 small earthquakes rumbled beneath the slopes of Mount St. Helens late last month, officials said, though the recent seismic activity does not necessarily foretell an impending eruption.
While the mountain responsible for the deadliest eruption in American history does not appear the be on the precipice of blowing its top, the recent quake swarms serve as a reminder that Mount St. Helens is still very active.
"Each of these little earthquakes is a clue and a reminder we are marching toward an eruption someday," Weston Thelen, a seismologist with U.S. Geological Survey's Cascades Volcano Observatory in Vancouver, told The Columbian, which first reported the story.
"There's nothing in this little modest seismicity, and none since 2008, that is a really good indicator of when that eruption will be," Thelen added.
Little is known about the exact origin of Mount St. Helens' magma. Recently, scientists found that the inside of the volcano was surprisingly cool and theorized that molten rock actually flowed in an underground plumbing system from east of the mountain.
Research raises questions about the mysterious source of Mount St. Helens' magma
It turns out the rock beneath the volcano's surface is actually quite cool.
Wherever the magma comes from, it constantly releases gas within the volcano, which experts believe could be the cause of the recent quakes. Most of the temblors were 1 to 2 miles beneath the surface and all of them were too weak to be felt above ground.
"We know Mount St. Helens is slowly repressurizing," Liz Westby, a Cascades Volcano Observatory geologist, told The Columbian. "We can't see it, but we think it's inflating subtly."
quote:Unexpected eruption of Bogoslof volcano Alaska
An unexpected, powerful eruption of Bogoslof volcano, Alaska occurred at about 00:35 UTC on December 21, 2016. The eruption lasted about 30 minutes and sent volcanic ash to an estimated altitude of 10.3 km (34 000) above sea level. The Aviation Color Code was briefly raised to Red. The last eruption of this volcano took place in 1992.
According to Alaska Volcano Observatory (AVO), a short-lived explosive eruption was reported by several pilots.
Satellite data showed a discrete explosion that detached and drifted to the south by 01:15 UTC. The Aviation Color Code was increased to Red and the Volcano Alert Level to Warning.
A subsequent pilot report from 01:50 UTC indicated that activity had decreased and the cloud was dispersing.
The ash cloud was carried southward over the Gulf of Alaska and no ash fell on inhabited areas. No further explosions have been detected in seismic and infrasound networks indicating that the activity has subsided.
quote:Bogoslof volcano keeps erupting
Alaska's Bogoslof volcano blows an island to smithereens and sends ash 35,000 feet into the air in repeated eruptions
Alaska's remote Bogoslof volcano keeps erupting, and has demolished much of its Aleutian island home with a string of huge explosions.
The latest event on Thursday sent a cloud of ash and ice 35,000 feet in the air, prompting the Alaska Volcano Observatory to issue its highest alert for aircraft.
The Federal Aviation Administration says the volcano had no immediate effect on flight operations.
quote:The volcano's activity remains above average. Vulcanian-type explosions from the summit crater occur at intervals of several hours and are sometimes very powerful, generating dense ash columns that rise 2-4 km, and cover the upper slopes of the volcano with bombs.
Some of them also generate small pyroclastic flows descending the steep upper flank.