SANTA CRUZ DE TENERIFE, December 12 (EUROPA PRESS) –
The amplitude of the signal of the volcanic tremor associated with the volcano on the island of La Palma has returned to low levels after the explosive episode two hours ago, in which a peak of activity was observed, as reported by Itahiza Domínguez, seismologist of the National Geographic Institute (IGN), who added that it will be necessary to continue observing this event, because “we could be facing a pause but it may be ephemeral.”
The director of the National Geographic Institute (IGN) in the Canary Islands and spokesperson for the Scientific Committee, María José Blanco, reported at a press conference that during this rebound there have been strong intensification pulses in the volcanic tremor signal that has been accompanied by the emission of ash, continuous sound and ejection of volcanic bombs on the eastern slope of the cone, as well as a small overflow to the north of the pre-existing stream that runs over previous streams. However, he added that at this time the sound and the emission of ash and gases have stopped.
The technical director of Pevolca, Miguel Ángel Morcuende, pointed out that this episode has occurred after 36 hours in which the volcanic activity has passed “quite calmly”, with a “not excessive” lava emission. Likewise, he indicated that at the moment the Military Emergency Unit (UME) is monitoring the pouring that runs to the north, which, he reiterated, advances on previous pourings.
Until the appearance of this new stream, most of the energy from the cone was flowing over previous streams, specifically over the central and southern areas, heading towards the area where streams 9 and 11 have joined, heading to the sea. Thus, the area affected by lava continues to be estimated at 1,184 hectares, with a maximum width of 3,350 meters, and the total extension of the lava deltas is maintained at 48.05 hectares, of which 5.05 hectares correspond to the northernmost delta. . Also, according to data from the Cadastre, 1,642 buildings have been destroyed, of which 1,314 are for residential use.
Regarding air quality (SO2), Miguel Ángel Morcuende indicated that the dynamics of recent days are repeated in reference to the presence of gases, giving high values in Las Manchas and acceptable values in Puerto Naos at dawn today, values that They are permanently monitored by the UME.
In this regard, he specified that while certain pulses are produced in the northern area of the emergency, especially in terms of SO2, in areas such as Los Llanos, Tazacorte or Puntagorda, these are of short duration and, in general, the levels of Air quality ranges from fair to good. In the southern zone there are many problems in terms of the levels of sulfur dioxide, carbon monoxide and carbon dioxide, which often prevents access to neighborhoods such as Las Manchas, Las Norias or La Bombilla.
On the other hand, about housed in hotels, there are 547 people, one less than yesterday. Of the total, 396 are staying in Fuencaliente, 69 in Los Llanos de Aridane and the remaining 82 in Breña Baja, managed by the Red Cross and municipal services. In addition, there are 43 dependent people cared for in insular health centers.
SCIENTIFIC COMMITTEE REPORT
From the effusive focus located in the west of the main cone, the lava continues to flow through a volcanic tube, which has several jameos, from which two streams depart that move west over previous streams. The most active, which converged on the stream that emerged west of the Cogote Mountain (currently inactive), continues on the latter, falling, according to two branches, on the low island in the Las Hoyas area. From this more active stream some lobes emerge that move southward, invading unaffected terrain in the Las Norias area.
Likewise, the other emission centers of the main cone are very little active, with pulses of strombolian activity and ash emission (in the southeastern part) and very intense gases. The cracks and fractures in the upper part of the secondary cone (concentric and radial with respect to the cone) have been modifying the morphology of this cone, generating the sudden movement of some blocks limited by these cracks and producing small landslides towards its interior and adjacent craters. .
The height of the volcanic plume measured this morning has been 1,400 meters and is disposed towards the west-southwest.
Regarding the meteorology, the prevalence of the northeast wind continues to the east component from low levels to about 5,000 m. The volcanic plume is expected to continue to face south-southwest from the eruptive focus. The expected disposition of the plume represents a favorable scenario for aeronautical operations. This situation is expected to continue until next Tuesday, when a turn of the wind to the west component is expected. This Monday the presence of haze is expected to increase PM10 values due to the contribution of desert dust.
In addition, the situation of atmospheric stability will continue for the next few days, until the end of Tuesday-Wednesday, when the lowering of a pocket of cold air at height will produce a significant increase in instability in the surroundings of the Archipelago. By the end of Tuesday rainfall can be locally moderate, mainly in the north and east of La Palma. There is high uncertainty regarding the location of the cold core for Wednesday and at the moment the numerical prediction models indicate that the most active area would affect the northeast of Tenerife.
Seismicity at intermediate depths continues to be low in the last 24 hours, being located in the same areas. The number of earthquakes at depths greater than 20 km remains very low. The maximum magnitude was 3.2 mbLg of an event recorded today at 5:21 am, at a depth of 36 km. The tremor level is at low values with little variability. Regarding deformations, no trend in the stations near the eruptive center and stability in the rest of the network.
The emission of sulfur dioxide (SO2) associated with the volcanic plume yesterday was high. The time series for the emission of sulfur dioxide (SO2) continues to reflect a downward trend since last September 23, when an extremely high emission of sulfur dioxide (SO2) was recorded.
In the case of the non-visible emanations of volcanic gases, the diffuse emission of carbon dioxide (CO2), associated with the Cumbre Vieja building, continues to reflect an emission higher than the average value of the background levels (B) and during the day of yesterday this diffuse emission was 6.9 times the average of the background levels (6.8xB).
These diffuse fumes do not represent a danger to people, unless accumulations of CO2 form in poorly ventilated depressions, displacing oxygen from the air and generating anoxic environments. In fact, relatively high values of diffuse CO2 flux have been recorded in the La Bombilla area and the presence of dead birds has been observed.
With regard to particles smaller than 10 microns (PM10), today all stations are at reasonably good and good levels.
