Posts Tagged "lahar"

When Lava Hits Ice in Russia’s Far East

Posted by on Feb 15, 2017 in All Posts, Featured Posts, News, Science | 0 comments

When Lava Hits Ice in Russia’s Far East

Spread the News:ShareThe Kamchatka Peninsula in Far East Russia is an isolated region known for its glacier-volcano interactions that can lead to powerful natural disasters— and also, visually stunning images when lava impacts ice. One of these volcanoes, Sheveluch, has been erupting in recent weeks, creating local hazards. The volcano’s ash cloud, for one, threatens to disrupt air traffic in the region. In total, Kamchatka is home to 160 volcanoes, 29 of which are currently active. These volcanoes— six of which are designated UNESCO World Heritage sites— are tall and far enough north to harbor glaciers. As such, they are associated with lahars, devastating mudslides down the slopes of a volcano triggered by an eruption and melting glaciers. These mudslides move quickly, destroying most of the structures in their path. Explosive-effusive #eruption of 2016 (April to October)#volcano #Klyuchevskoy 08/21/2016Photo: Vladimir Voychuk pic.twitter.com/5wOhpyVg1s — Войчук Владимир (@voy4uk) January 26, 2017 Avachinsky is one active volcano in the region that is covered in glaciers, placing the surrounding region at a greater risk for lahars. Avachinsky is classified as a stratovolcano, which is a volcano that has been built up by alternate layers of lava and ash. It is the volcano closest to the state capital Petropavlovsk-Kamchatsky.  “The Avachinsky volcano is glacierized, and the melting of ice poses a serious lahar threat the next time the volcano is active,” Ben Edwards, a volcanologist and professor at Dickinson College, warns. Edwards explained to GlacierHub that there are many deposits mapped out that are indicative of past lahars. Previous lahars in the Kamchatka Peninsula have been devastating with high human death tolls. The Nevado del Ruiz volcano in Colombia, for example, erupted in 1985, producing a lahar that killed 23,000 people. “They are incredible forces of nature and also brutally destructive and deadly,” said Janine Krippner, a PhD candidate in volcanology and remote sensing at the University of Pittsburgh, in an interview with GlacierHub. The Klyuchevskaya Sopka stratovolcano is the highest mountain on the peninsula and the highest active volcano in Eurasia. In November 2016 and more recently in January, the volcano spewed ash six kilometers above sea level. Such an ash cloud can disrupt international travel. Klyuchevskaya has produced notable lahars in the past including one particularly damaging one in 1993, according to Edwards. The position of a glacier on a volcano can influence the risk of a lahar.  However, there is still much research needed on past lahars at Klyuchevskaya to better understand risk, notes Edwards. “Many volcanoes have glaciers up high, but those close to Klyuchevskaya are on the western lower flank,” explained Edwards. “There have probably been some interactions and definitely lahars generated from historic flows. But these eruptions have not been well documented.” Higher regions, which tend to be cooler and moister, are more likely to form glaciers. Sheveluch Peak is a very active volcano, and the largest on the peninsula at 1,300 cubic kilometers in volume. Many glacier-volcano interactions have occurred at the location, releasing great quantities of steam and creating fantastic imagery for photographers. Similar volcano-snow interactions also take place elsewhere on the peninsula, especially during the winter, according to Edwards. “We saw spectacular examples during the 2012-13 Tolbachik eruption,” he said. The World Heritage website, which features several of the Kamchatka Peninsula volcanoes, makes special note of the “dynamic landscape of great beauty” created by the interplay of active volcanoes and glacier forms. In addition, the peninsula has a wide diversity of species including brown bears, sea otters and the world’s largest variety of salmon fish. It is also known for a wide variety of birds from falcons to eagles that are attracted to the...

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Photo Friday: Volcanic Readiness in Colombia

Posted by on Aug 26, 2016 in Adaptation, All Posts, Communities, Featured Posts, Images | 0 comments

Photo Friday: Volcanic Readiness in Colombia

Spread the News:ShareThe Volcanic and Seismological Observatory of Manizales has recently conducted several workshops on volcanic risk with communities in the vicinity of Nevado del Ruiz, a glacier-covered volcano in Colombia that showed signs of renewed activity earlier this year. The workshops prepare communities to react to volcanic hazards like ash and lahars, the latter of which can occur when lava flow mixes with the icy temperatures of glaciers. Locals participate in focus groups and model experiments to better understand the volcanic risks in their community. “Communication Strategy of Volcanic Risks,” is enacted in conjunction with the Colombian Geological Service, the National Unity of Disaster Risk Management, and other regional and municipal agencies. Check out some photos of the workshop, courtesy of the Observatory, below. A focus group in Los Alpes. A demonstration activity with the community of Playa Larga. A demonstration activity in Los Alpes. Los Nevados National Natural Park, with the Nevado del Ruiz in the far distance. Source: Juan Camilo Giraldo Falla. A demonstration activity with the community of Playa Larga. Click here to “like” the Observatory’s Facebook page and to see more photos of the project.   Spread the...

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Renewed Activity at Colombian Volcano Raises Concern

Posted by on Jun 29, 2016 in All Posts, Featured Posts, News | 0 comments

Renewed Activity at Colombian Volcano Raises Concern

Spread the News:ShareThe glacier-covered Volcan del Ruiz in Colombia has shown signs of renewed activity in the last several days, following a shallow earthquake of 3.0 on the Richter scale on June 22, associated with fracturing of rock within the volcano. The Colombian Geological Service recognized this fracturing as a sign of possible movements of magma that could lead to an eruption of lava. Tom Pfeiffer, a German volcanologist, suggested that the earthquake was “possibly caused by increased magma pressure inside the volcano’s upper storage system.” Earlier this week, on June 27, the volcano released an ash cloud, reaching 1,800 meters above the summit. A second emission on June 28 attained a height of 850 meters. Its volume was sufficient to threaten aircraft in the region, which led to the sudden closure of the regional airport in Manizales, 25 kilometers to the northwest. One local resident released alerts on Twitter, directing people to close windows and to wear face masks as protection against the ash. In a second tweet, included below, she indicated that the warning level had been raised from yellow to orange, “alerta naranja,” though official sources in the Colombian Geological Service and the regional Risk Management Unit wrote to assure the public that the warning level remained at yellow. Alerta explosion en el volcan arenas nevado del ruiz hace 15 minutos.alerta naranja pic.twitter.com/wofG5FcLBs — ANGELA (@abeta13) June 28, 2016 On its Facebook page, the regional Volcanic and Seismological Observatory released a video of the most recent eruption, taken on its webcam: As GlacerHub explained in a recent post, the presence of glaciers on the volcano’s summit creates the risk of destructive debris flows known as lahars. The very rapid melting of ice caused by contact with molten lava can cause floods to rush down the mountain’s slopes, carrying large quantities of ash, rock and soil to populated areas. An eruption of the volcano in 1985 led to over 23,000 deaths. The Colombian authorities and local citizens are monitoring this situation closely. If an eruption is likely, the municipalities in the region will receive warnings. GlacierHub will report on any significant intensification of the volcano’s activity. Spread the...

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Activity in Colombian Volcano Sparks Concern

Posted by on Jun 1, 2016 in All Posts, Featured Posts, News | 0 comments

Activity in Colombian Volcano Sparks Concern

Spread the News:ShareA large glacier-capped volcano in Colombia, the Nevado del Ruiz, has shown significant activity in recent weeks, raising fears of destructive mudflows known as lahars. Photographers recorded ash emissions starting on May 19. The Colombian Geological Service noted volcanic activity and tremors at the volcano early on the morning of May 22. The 5,321 meter high stratovolcano, located in Colombia’s Los Nevados National Park, initially emitted a 1,300-meter plume of ash at 2:35 a.m., followed by a second 2,300-meter plume at 5:51 a.m. causing the temporary shut down of La Numbia Airport. Activity continued through May 25, when an additional ash emission occurred at 7:00 a.m. Though the volcano has not erupted, conditions remain unstable and the possibility of further activity is being closely monitored, particularly since the seismic activity suggests the movement of magma in the volcano, raising the possibility of an eruption. The Colombian Geological Service has set the warning level at yellow.  The volcanic activity at Nevado del Ruiz sparked concern from the scientific community, as the volcano is historically known for its deadly eruptions. When the Nevado del Ruiz erupted in November of 1985, it caused what is today considered the worst volcanic disaster in South America’s history, and the fourth worst in the world. Over 23,000 Colombians were killed, with the majority of fatalities in the town of Armero. However, it was not the eruption itself that caused such extensive damage—the glaciers at the summit of Nevado del Ruiz are what made the event so deadly. Volcán del Ruiz, belleza al amanecer https://t.co/0uf0sBJxvy vía @lapatriacom pic.twitter.com/3VjTOReR1W — Periódico LA PATRIA (@lapatriacom) May 31, 2016 “Glaciers and volcanoes can be a particularly hazardous combination,” commented Jerry McManus of Columbia’s Lamont-Doherty Earth Observatory in an email to GlacierHub. “The snow and ice provide a ready source of water for the potential generation of destructive lahars during eruptions.” Lahars, rather than lava, are what leveled the town of Armero and caused the resulting fatalities. Lahars are large mudflows caused by summit glacier melt during an eruption. The combination of water and volcanic rock debris, known as pyroclastic material, creates a material similar to liquid concrete. The 1985 eruption of Nevado del Ruiz created four lahars, which flowed down the volcano at speeds up to 30 kilometers per hour. Armero, located 48 kilometers from the base of the volcano, did not have time to prepare or evacuate. In the aftermath of the disaster, the Colombian government was strongly criticized for underestimating the dangerous impacts of the relatively small eruption despite warnings from volcanologists. The population of the region has grown over the past three decades, putting more people at risk if an eruption is triggered. Over 500,000 Colombians live within 30 kilometers of the volcano, well within the range of a lahar—significantly closer than Armero.  With the disaster still fresh in the minds of the Colombian government and scientific community, the current activity at the Nevado del Ruiz is being more closely monitored. Spread the...

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A Glacier-covered Volcano in Chile: Will It Erupt Soon?

Posted by on Feb 2, 2016 in All Posts, Featured Posts, News, Science, Uncategorized | 0 comments

A Glacier-covered Volcano in Chile: Will It Erupt Soon?

Spread the News:Share Several recent events suggest that a set of glacier-covered volcanoes in the southern Chilean region of Bío-Bío, which have been showing increasing activity since December, may be likely to erupt.  The three mountains, known as the Nevados de Chillán, reach over 3200 meters in elevation, and have a set of glaciers totaling over 2 square kilometers in area on their summits. They have a long record of eruptions, with historical documentation from the 17th century. Radiocarbon evidence records eruptions that took place about 8000 years ago.   The Nevados de Chillán complex, which averaged about one eruption a decade during the 19th and 20th centuries, had been relatively quiescent since an eruption in 2003. Sticking roughly to that schedule, the complex began to show signs of returning to activity with an earthquake in February 2015 which registered 3.2 on the Richter scale. The Chilean National Geology and Mining Service (SERNAGEOMIN) maintained the volcano warning at the lowest level, green, until 31 December, when it issued a yellow warning, signaling an intermediate level of danger. This shift was prompted by the appearance of a new gas vent on 8 December and by a series of over 2000 small seismic events, all under 2.0 on the Richter scale, throughout the month,  which indicated the fracturing of solid rock and the upward movement of magma beneath the surface. This activity has picked up in January, with the opening of a second new vent on 8 January, accompanied by a 2.9 earthquake and a cloud of ash. SERNAGEOMIN and the National Office of Emergencies (ONEMI) installed two webcams near this vent on 27 January. Providing these cameras with material to record, new clouds of ash appeared on 29 January. On 30 January, a crater, about 25-30 meters in diameter, appeared near the other new vents, with gasses, ashes and occasional blocks of cooled lava emerging from it. Temperatures at the summit were about 125º C, which was consistent with ongoing hydrothermal activity but did not suggest that magma, typically closer to 1000 º C in temperature, was approaching the surface.  Taken as a whole, these new activities led ONEMI to create a 2-km zone around the new craters from which people are excluded.  The local sense of concern was increased by the wide availability of images from the new cameras and from an impressive thunderstorm on 31 January, as shown below: @biobio @RoloHahn tormenta eléctrica en la precordillera de chillan pic.twitter.com/u8DXZiSq7I — orlando bustamante (@treguil) February 1, 2016 Dave McGarvie, a volcanologist with considerable experience in ice-covered volcanoes, has been working around Chillán since 2001. In his blog, he offers this overview of the situation: What makes me think that this unrest is likely to lead to an eruption? Well there are two main reasons.   Firstly, there’s clearly been a new heat source introduced into the plumbing system beneath the volcano, and this had drilled a new pathway to the surface leading to bursts of heat escaping through a new vent. This heat source is almost certainly due to magma rising up in the plumbing system. And at the moment there’s a ‘vent-cleaning’ phase in place, with bursts of heat interacting with water contained within the cone (Hydrothermal). There are probably magmatic gases involved as well. These energetic outbursts are cleaning out material in the developing conduit, and possibly also pulverizing (fragmenting) material being blown out.   Secondly, this new vent has developed on the youngest cone at this volcanic complex, which has developed through a long series of eruptions, punctuated by time gaps of a few years to decades. McGarvie’s assessment is that an eruption in the near...

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