Volcán Calbuco erupted on Wednesday, April 22, 2015, and caused airline flight cancellations and evacuation of the surrounding countryside. A flow of lava was reported into Chapo Lake. So far, no casualties have been reported, but one traveller seems to be missing.
Calbuco (Spanish: Volcán Calbuco) is a stratovolcano in southern Chile, located southeast of Llanquihue Lake and northwest of Chapo Lake, in the Los Lagos Region. The volcano and the surrounding area are protected within Llanquihue National Reserve. It is a very explosive andesite volcano whose lavas usually contain 55 to 60% silicon dioxide (SiO2). It underwent edifice collapse in the late Pleistocene, producing a volcanic debris avalanche that reached the lake.
Calbuco has had at least 10 eruptions since 1837. One of the largest historical eruptions in southern Chile took place there in 1893–1894. Violent eruptions ejected 30-cm bombs to distances of eight kilometres from the crater, accompanied by voluminous hot lahars. Strong explosions occurred in April 1917, and a lava dome formed in the crater accompanied by hot lahars. Another short explosive eruption in January 1929 also included an apparent pyroclastic flow and a lava flow. A major eruption of Calbuco in 1961 sent ash columns 12–15 km high and produced plumes that dispersed mainly to the south east and two lava flows were also emitted. There was a minor, four-hour eruption on August 26, 1972.
About 5,000 people have been evacuated so far, the AFP reports. Puerto Montt, population 212,000, and Puerto Varas, population 41,000, the nearest sizable towns, are about 30 kilometers away. Schools and flights to a nearby airport have been cancelled and emergency services are headed to the region, the AP reported.
Timelapse and 2 videos of the Calbuco eruption in the region of Los Lagos, Chile. By Dario Almonacid of TodoPuertoMontt:
April 22, 2015
(All translations by Google)
From the report on 22 April 2015, 20.45 LT (OVDAS, RNVV, SERNAGEOMIN)
Based on the analysis of information obtained through monitoring stations installed near the Calbuco Volcano, we report the following:
– Today, April 22, at 18:04 local time (21:04 GMT), there was an unexpected eruptive event in the Calbuco volcano, focused on the main crater.
– This event was preceded by increased seismic activity in the associated area of the volcano (see previous REAV), which began about an hour before the event with greater seismic, with the event log type VT, located in the east side of the volcanic edifice, near the main crater. After this episode (17:35 Local Time) we began recording the type LP earthquakes associated with fluid dynamics within the volcano, which had a reduced maximum displacement of (DR c) 5890 cm2.
(Event recorded at 17:54 local time, 20:54 GMT) with an amplitude of 1723
um / s dominant frequency of 0.75 Hz. Note that the seismic activity associated with the volcano showed no significant increases in any of their values from 2009 when the seismic monitoring began in real time by the OVDAS.
– After an increase in seismicity (17:54 Local Time), an eruptive column was generated from
greyish vigorous character in the paroxysmal stage, which reached a height greater than 15 km on the main crater. The pyroclastic dispersal has been mainly to E-NE of the volcano. Collapses under the eruptive column have occurred locally radially, affecting the headwaters of major rivers.
– At the time of issuance of this report, surface seismic activity continues with values considered high, now with the presence of a signal type tremor (TR) continuous, associated with fluid dynamics within the massif.
In the current scenario pyroclastic dispersal and accumulation is expected towards the N_NE-E
(Number and occurrence of minor pyroclastic flows in the main valleys descend the volcano whose scope would not exceed 20 km (worst scenario of record geological)
Technical Alert Level remains at RED.
From the report on 22 April 2015, 22.30 LT (OVDAS, RNVV, SERNAGEOMIN)
The eruptive activity of the volcano Calbuco ended its most energetic phase, which lasted 1 hour and 30 minutes, developing an eruptive column of about 15 km hight above the main crater, at the time of issue of this report moderate levels of seismic noise near background values are recorded.
– At 21:55 local time (00:55 GMT) began to register a harmonic tremor with an amplitude of 5 microns/sec and a reduced displacement of DR = 2.6 cm2 suggesting possible emission of lava from the main crater. At the time of issuance of this report, seismic activity continues in amounts considered moderate.
– The pyroclastic dispersion in the atmosphere has been essentially to the N and E of the volcano.
However, fine ash that is being transported to the N and NW can reach the regions of Los Ríos, Araucanía and Bío-Bío in the coming hours. Fine ash fall of millimeter thickness is expected.
This eruption was unexpected as the volcano was on green alert status (lowest) until a volcanic tremor swarm began in the mid-afternoon today [Wednesday] at the volcano. Within as little as 15 minutes, the eruption commenced. This suggested rapid ascent of magma from its source under the volcano but as the intensity of the eruption appears to have waned as nightfall arrived. (E. Klemetti)
Sorry, WP does not let me display the refreshable webcam here, so, for the time being, I have placed it in the side bar instead. There it works ok, refresh with F5.
From the report on 23 April 2015, 01.10 LT (OVDAS, RNVV, SERNAGEOMIN)
– At 01:00 local time (0400 GMT), there was a new eruptive pulse on the volcano Calbuco. At this time evolution of the eruption is evaluated, it is recommended to continue a restricted area of 10 Km. Technical Alert Level remains at RED.
“For us it was a surprise,” said Alejandro Verges, regional emergency director of the Los Lagos region where the eruption took place. He said Calbuco wasn’t under any special form of observation. Authorities said a large amount of ash was observed, but no hot rocks or lava had been seen by late in the day. No injuries were reported, but one hiker remains missing.
There are now concerns that the ash cloud could contaminate water, cause respiratory problems and ground flights. The Education Ministry cancelled school in communities near the volcano and at least three flights to Puerto Montt were cancelled.
“This is clearly a much larger eruption than the one we saw in Villarica some weeks ago and therefore we need to take bigger and faster measures,” Interior and Security Minister Rodrigo Penailillo said. He said that the government was sending water in case resources get contaminated by ash and that police and military officers had been deployed to ensure safety and help with evacuations.
Saturday, 25 April 2015
News from several newspaper reports:
– Some houses and schools located close to the volcano have collapsed under the weight of the ash.
– Ash from Calbuco reached as far as southern Brazil on Saturday and prompted some airlines to cancel flights to the capitals of Chile, Argentina and Uruguay.
– Authorities have decided to keep the RED alert as well as the 20 km exclusion zone around Calbuco. Authorities urged 2,000 people living near the Calbuco volcano to evacuate Friday after potentially devastating mudflows of volcanic debris were detected in a nearby river. The number is now more than 6,500 people who have been evacuated in the scenic Los Lagos region.
– The head of Chile’s mining and geological service said on Friday the volcanic process could last for weeks. Main threats, beside the health risks of air-suspended ash, are the expected lahars and possibly landslides ensuing after deposition of the huge amounts of ash.
– An attempt to rescue live stock and pets had to be aborted today because of lahars and rising flow rates in rivers. It is to be resumed tomorrow, conditions permitting.
Sunday, 26 April 2015
Observatorio Volcanológico de los Andes del Sur – OVDAS:
Report from Saturday, 16:00 (Google translation)
Continued constant emission of ash with a column up to 2 km from top of the volcano. Secondary explosions have been observed temporarily, correlated with sporadic seismic signals associated with fluid movement within the volcano (signal type LP and TR). This suggests sustained activity of the volcanic system, which could be a precursor of magmatic processes associated with the emission of lava flows and/or the lava dome surface. The processes that occurred in the most intense phase of the eruption, and the current system instability, generated favorable conditions for the renewal of the eruptive activity and therefore we suggest keeping the restriction in an area defined by a radius of 20 km around the volcano. Moreover, unstable pyroclastic material accumulated at the top of the volcano and its slopes, as well as surrounding areas, could be remobilized by rain giving rise to ‘secondary lahars’ (volcanic mudslides caused by partial remobilization of pyroclastic material) down the slopes and river valleys.
Tuesday, 28 April 2015
SERNAGEOMIN/OVDAS 16.00: At dawn today an increase of continuous tremor was recorded temporally correlated with activity at the surface level, which generated nocturnal glow. However, the seismic signal returned to low levels in the early morning hours and remained stable since. Also continues the permanent particle emissions to surface, but with a weak spine, sparse and lower height (<1.5 km). Although the process has lost power, yet the probability that the system evolves towards volcanic conditions remains conducive to reactivation of the eruptive activity. It is suggested to pay special attention to the occurrence of lahars and mudslides due to forecast rains in the coming days, particularly in the channels that descend from the volcano, in a strip 200 m wide on each side of them, and in other sectors where there is significant accumulation of pyroclastic material.
Thursday, 30 April 2015
The third eruption of Calbuco ocurred this afternoon with a 3000m black ash plume going in SE direction and primary lahars, according to SERNAGEOMIN on Twitter. It was preceded by a new phase of seismic unrest and harmonic tremor. The 20 km restriction zone had to be evacuated again as people had begun going back home to look after their animals and properties. This eruption has been smaller than the previous two. Scientists had projected the behaviour of the volcano correctly after the first two eruptions and have earlier warned the population to expect more eruption cycles of similar nature.
Tuesday, 5 May 2015
No changes so far. SERNAGEOMIN state in their reports that the condition of Calbuco remains unstable, seismicity is fluctuating and further eruptions can not be excluded. The restriction zone of 20 km radius and the danger areas for possible mud flows/lahars along the rivers are still maintained.
Enjoy! Spica & Granyia
SOURCES, NEWS and MORE IMAGES
Eruptions – Erik Klemetti
Los Angeles Times
A german article