February 05 , 2017. EN. Piton de la Fournaise , Bogoslof , Sabancaya , Colima .
February 05 , 2017.
Piton de la Fournaise , La Réunion :
The eruption begun on January 31, 2017 at 7:40 pm local time continues. The volcanic tremor (surface eruptive indicator) has again experienced significant fluctuations for more than 24 hours, with intensity levels reaching those observed at the beginning of the eruption (Figure 1).
Figure 1: Evolution of RSAM (volcanic tremor and eruption intensity indicator) between 7:00 am (1am UTC) on January 31st and 5pm (1pm UTC) on February 4th on the seismic station of Château Fort, located on the Southern flank of the volcano. (© OVPF / IPGP)
– No significant deformation was recorded during the day on the terminal cone.
– No seismicity was recorded during the day under the Piton de la Fournaise volcano.
Due to the bad weather early this morning and the pre-alert cyclone, no ground or aerial reconnaissance was carried out today by the volcanological observatory. Similarly, no surface flow could be estimated by satellite method.
Extract from the press release of the prefecture of Reunion
« Public access to the Enclos Fouqué , whether it be from the footpath of the Pas de Bellecombe or from any other path as well as the helicopter landing in the area of the volcano are prohibited until further notice. »
Source : OVPF
Photo : S. Conejero
Bogoslof , Aleutians Islands , Alaska :
53°55’38 » N 168°2’4″ W,
Summit Elevation 492 ft (150 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Two eruptive episodes from Bogoslof Volcano occurred yesterday. The first episode was detected on seismic instruments beginning at 4:57, February 3 AKST (13:52 UTC). No ash cloud was seen in satellite imagery but the activity was seen on infrasound instruments indicating that a likely low-level emission had occurred. An increase in seismic tremor was again detected on seismic instruments at 18:41 February 3 AKST (1:41 February 4 UTC) and was also seen on infrasound instruments. Satellite observations and pilot reports confirmed a small volcanic ash plume below 25,000 feet above sea level and tracking to the north. By 20:20 AKST the cloud was no longer distinguishable from the meteorological clouds. Seismicity through this morning has been quiet. No activity has been detected in partly cloudy satellite data.
Features and deposits on Bogoslof Island after the eruptive events of January 30-31, 2017. Shallow groundwater flow through the new volcanic deposits from the sea toward the center depression has resulted in the formation of concentric headscarps and channels. This process, called sapping, is common in areas of concentrated groundwater discharge where it undermines slopes and leads to headward erosion and the formation of arcuate headscarps. Rubbly appearing rock debris scattered over parts of the island was likely generated by near surface explosions of a still submarine lava plug, showering the island with blocks and bombs of rock debris. Some of these rock fragments are up to 2.5 m in length. The mound of tephra on the southern part of the island is a tuff cone, and the level area making up the northern half of the island is a tuff ring. These are characteristic landforms of shallow submarine eruptions. The Bogoslof Island landscape is susceptible to rapid erosion, primarily by ocean waves, and erosion of the surficial volcanic deposits will be ongoing and changes in the configuration of the island are likely. ©2017 Digital Globe NextView License. Base image Worldview-3, 1/31/2017.
Bogoslof volcano remains at a heightened state of unrest and in an unpredictable condition. Additional explosions producing high-altitude volcanic clouds could occur at any time. Some previous explosions have been preceded by an increase in earthquake activity that allowed for short-term forecasts of imminent significant explosive activity. Although we are able to detect energetic explosive activity in real-time, there is typically a lag of tens of minutes until we can characterize the magnitude of the event and the altitude of the volcanic cloud. Low-level explosive activity that is below our ability to detect in our data sources may be occurring. These low-level explosions could pose a hazard in the immediate vicinity of the volcano. When such low-level activity occurs, it is considered to be consistent with Aviation Color Code ORANGE and Volcano Alert Level WATCH.
AVO has no ground-based volcano monitoring equipment on Bogoslof volcano. We continue to monitor satellite images, information from the Worldwide Lightning Location Network pertaining to volcanic-cloud lightning, and data from seismic and infrasound instruments on nearby islands for indications of volcanic activity.
Source : AVO
Photos : Waythomas, chris , Leary, Dan.
Sabancaya , Peru :
Last Thursday, on 26 January, a team of professionals from the Southern IGP (OVS-IGP) Volcano Observatory visited the Sabancaya to corroborate in situ the extent of its recent explosions and the maintenance of seismic stations of Telemetry that control the activity of this massif.
In their journey they found that the whole area adjacent to the volcano is covered with snow and subject to heavy precipitation. Nevertheless, they were able to distinguish different explosions that ejected ashes at a height of 2000 m above the edge of the crater. « Today the volcano is on the orange alert level. The Scientific-Technical Committee warned that the ash will be scattered about 40 km around the volcano, « said Dr. Orlando Macedo, director of the OVS.
Later they visited four of the five seismic stations of the local volcano monitoring network, providing preventive maintenance of its components to ensure the continuous recording of sismo-volcanic information. « Having this information 24 hours a day makes it possible to identify the different types of earthquakes and the source from which they come to determine the current stage of the eruption, » said the IGP scientist.
Seismicity associated with magma movement (LP and Tremor) showed no change, while that associated with magma uplift (HIB) increased slightly, recording up to 11 HIB / day on average this week .
An average of 70 explosions were recorded per day with a maximum reduced displacement value (DRC) of 84 cm2. There were three volcano-tectonic earthquakes of Type (VT) of size 3.7 ML, located 12 km north of the crater.
The eruptive columns of gas and ashes reached about 2800 meters above the crater and then spread over 40 km in the direction of SE and NW of the volcano.
The tendency to deform the solid mass lies within the error range of the instrument.
The volcanic gas flow (SO2) recorded a maximum of 2800 tonnes / day.
There were two thermal anomalies known on 29 January, both of which were 2 MW.
The activity of the Sabancaya remains moderate with continuous explosions and ash emissions.
Source : IGP
Colima , Mexico :
The colima volcano on Friday issued a new exhalation of ash and water vapor that reached a height of four kilometers, according to Luis Felipe Puente, national coordinator of civil protection of the Ministry of the Interior.
« The volcano Colima had an explosion at 17:32 hours, with a height of 4 km with a high ash content » he shared on his Twitter account.
The Jalisco State Civil Protection and Fire Unit also reported « the emission of glowing bodies on all sides of the volcano », which lies between this state and that of Colima.
The Ministry of the Interior’s National Civil Protection Coordination has reported that since October 2016, the Colima volcano has entered a period of mainly explosive activity, at irregular intervals, which has produced eruptive columns of different heights, from one to four kilometers high, sometimes with the launching of incandescent fragments at one or two kilometers from the crater, and occasional pyroclastic flows, with ranges between one and two kilometers.
Source : Telemundodallas , La Prensa ,
Photo : Hernando Rivera