January 14, 2016. EN. Nevado Del Ruiz , Sinabung , Semeru , Erebus .
January 14, 2016.
Nevado Del Ruiz, Colombie :
Weekly activity report of the Nevado del Ruiz volcano.
Subject: internal activity level of the Nevado del Ruiz volcano.
The level of activity continues at :
Activity level Yellow or (III): changes in the behavior of volcanic activity.
Regarding the monitoring of the activity of the Nevado del Ruiz volcano, the Colombian Geological Service reports:
During the last week, the volcanic system continued to show unstable behavior. The recorded seismic activity was mainly associated with the fracturing of the rock in the volcanic structure. This type of seismicity was located mainly in the distal areas at North, South, West and East of Arenas crater and, to a lesser extent in the crater itself and its surroundings. The depths of earthquakes during the week ranged from 0,78 to 8,83 kilometers, the maximum recorded was magnitude 2.6 ml (local magnitude), corresponding to an earthquake on January 6 , 2h06 p.m. (local time) in the Arenas crater at a depth of 0,78 km.
Regarding seismic activity related to fluid dynamics in volcanic pipes, this type of seismicity was characterized by the appearance of continuous tremors and earthquakes long period (LP), located mainly in the vicinity of Arenas crater and in the Southeast region of the volcano. The continuous tremor signal, had low energy levels and remained constant throughout the week. Do not rule out that new episodes of high energy levels of this signal and the gas expulsion and ash in the atmosphere may occur.
These processes were accompanied by thermal anomalies noted through monitoring by satellite images provided by different organizations, such as the Italian universities of Turin and Florence (Mírová portal). Moderate thermal anomalies on the 06, 09 and 11 January, which have been identified near the Arenas crater, confirming the instability of the Nevado del Ruiz volcano and confirming that the volcanic process continues to evolve.
The volcanic deformation measured from electronic inclinometers, satellite global navigation systems (GNSS) and satellite images, which record changes in tilt, position and shape of the volcano (respectively) during the last period evaluated, showed no significant changes.
The volcano continues to emit into the atmosphere large quantities of steam and gas, including sulfur dioxide (SO2), as has been estimated by the permanent stations SCAN DOAS installed in the volcano area and by imaging satellite.
The column of gas, steam and ash reached a height of 1400 meters above the summit of the volcano, January 9. The direction of the dispersion of the column is in line with the regime of prevailing winds in the area, which, during the week, showed a predominant direction towards North over the volcano.
Source : Sgc.gov.co.
Sinabung , Indonésie :
Elevation 2460 m
The volcano’s eruption continues with little changes . Slow lava extrusion at the summit results in occasional small to moderate pyroclastic flows as well as sporadic explosions.
This activity occurs in weeks-to-month long alternating phases of more and less intense frequency, as lobes of the overspilling dome grow too large and then break off to generate a series of collapses within a shorter time.
Both the pyroclastic flows and explosions produce ash plumes that regularly rise a few km above the volcano and are often reported by Darwin VAAC.
Based on information from PVMBG, ground reports, and satellite images, the Darwin VAAC reported that during 6-12 January ash plumes from Sinabung rose to altitudes of 3.7-4.3 km (12,000-14,000 ft) a.s.l. and drifted 15-40 km SW, W, NW, and NE
Source : Volcanodiscovery , Gvp .
Photos : Sadrah Peranginangin
Elevation 3676 m
PVMBG reported that during 1 November 2015-4 January 2016 white and gray plumes from Semeru rose as high as 500 m above the crater and drifted E, S, and W; inclement weather sometimes prevented observations. In November nine incandescent avalanches traveled 100-500 m down the flanks.
During December 2015-4 January 2016 incandescent material was occasionally ejected above the crater. Seismicity was dominated by signals indicating avalanches and emissions. The Alert Level remained at 2 (on a scale from 1-4); visitors and residents were warned to avoid the SE flank within 4 km of the crater.
Source: PVMBG, GVP.
Photo : Bromoeastjava.com
Erebus, Antartique :
Not often that has news and photos of one of the southernmost volcano in the world.
A steamy day for Mount Erebus, Antarctica, as UNAVCO field engineers perform maintenance on continuous GPS stations for Mount Erebus Volcano Observatory.
Mount Erebus, the world’s southernmost historically active volcano, overlooks the McMurdo research station on Ross Island. The 3794-m-high Erebus is the largest of three major volcanoes forming the crudely triangular Ross Island. The summit of the dominantly phonolitic volcano has been modified by one or two generations of caldera formation. A summit plateau at about 3200 m elevation marks the rim of the youngest caldera, which formed during the late-Pleistocene and within which the modern cone was constructed. An elliptical 500 x 600 m wide, 110-m-deep crater truncates the summit and contains an active lava lake within a 250-m-wide, 100-m-deep inner crater. The glacier-covered volcano was erupting when first sighted by Captain James Ross in 1841. Continuous lava-lake activity with minor explosions, punctuated by occasional larger strombolian explosions that eject bombs onto the crater rim, has been documented since 1972, but has probably been occurring for much of the volcano’s recent history.
Sources : Unavco , Gvp
Photo : Joseph Pettit, UNAVCO