SANTA CRUZ DE TENERIFE, Oct 19 (EUROPA PRESS) –
The spokesperson for the Pevolca Scientific Committee and director of the National Geographic Institute (IGN) in the Canary Islands, María José Blanco, has insisted that it is still not possible to talk about the end of the eruption of the volcano on the island of La Palma in the short or medium term , despite the fact that sulfur dioxide (SO2) emission rates have been declining in recent days.
María José Blanco pointed out at a press conference that, as indicated by the Volcanological Institute of the Canary Islands (Involcan), the SO2 emission rates have been decreasing in recent hours, but stressed that they would have to reach values lower than the data registered in the today (9,938 tons) so that it can be said that the eruptive process can come to an end.
The spokeswoman for the Scientific Committee has reiterated that “we are still far” from that happening, since values are being recorded that, although lower, can still be classified as high. For his part, the technical director of Pevolca, Miguel Ángel Morcuende, specified that although they may seem somewhat lower amounts than those of the past few days, these are underestimated values and that they are still “well above” what could be the beginning of the end of volcanic activity.
Asked about the lower activity registered today in the issuing center, María José Blanco recalled that already on September 27 there was a total stoppage of the tremor signal and visible surface signs for a few hours and finally ” it did not mean anything “, because then” more visible and more explosive “phases began than the previous days, so it may be something” ephemeral “and that it resumes the previous activity.
As for the daily report of the Scientific Committee, it indicates that the fissure eruption continues to show a strombolian mechanism and the Volcanic Explosivity Index (VEI), with values between 0 and 8, remains so far at 2.
The emission center that was reactivated on the 16th continues with its intermittent ash emission activity. The appearance of new emission centers around the main cone, as well as other surface observables (visible gas emissions) within the exclusion zone, is not ruled out.
The morphology of the cone changes repeatedly due to the successive processes of growth and reconfiguration. The eruptive process can show episodes of increased and decreased strombolian activity, as well as pulses with phreatomagmatic activity. The height of the ash and gas column measured today, as well as its dispersion, reaches 5,000 meters.
Today it is expected that the Saharan air mass will be remitting, which is contributing particulate material of up to 10 microns (PM10). The thermal inversion will continue at low altitudes (below 500-1,000 m) until the next day 22, which will recover typical values for the time of year. The above, together with the scarce ventilation that exists in low areas of the west of La Palma, are unfavorable conditions from the point of view of air quality.
At altitude (between 1,500-3,000 m) the wind from the northeast component to the south component will predominate and the most probable position of the ash plume and SO2 is a disposition towards the north from the eruptive focus. The wind is expected to turn north-northeast at levels between 1,500 and 3,000 m and this distribution of the wind will dispose the plume towards the southwest of La Palma. It is not ruled out that the ashes may affect the operation of the Airport today and early tomorrow. As of tomorrow, the scenario is more favorable for the operation of the Airport.
Seismicity continues to be located, mainly, close to the seismicity of the first days, at depths between 10 and 15 km. There are also earthquakes located at depths greater than 20 km. The high values of the amplitude of the tremor signal are maintained, with intensification pulses. The maximum magnitude observed in the last 24 hours has been 4.3 mbLg of an event at a depth of 37 km, and felt with intensity of III-IV EMS. The current level of seismicity continues to indicate that more felt earthquakes are possible, which could cause small landslides in sloping areas. No significant surface seismicity is recorded.
The deformation shows a pattern of stability around the eruptive center and a slight regional deflation of deep origin detected in the stations furthest from the eruptive center.
During yesterday, the emission of sulfur dioxide (SO2) associated with the volcanic plume (visible emanations of volcanic gases) continues to register high values and in line with the eruptive process, reaching values of 9,938 tons per day (underestimated value). Likewise, the diffuse emission of carbon dioxide (CO2), associated with the 220 km2 of the volcanic ridge of Cumbre Vieja (non-visible emanations of volcanic gases), reflects a downward trend since last day 12 and has been estimated at 822 tons per day as of yesterday. The diffuse CO2 emission at the Los Llanos geochemical station (LP10) reflects a higher magmatic-hydrothermal fraction than that observed at the Fuencaliente geochemical station (LP08). All these geochemical observations are consistent with the current eruptive process.
Regarding air quality, regarding sulfur dioxide (SO2), yesterday the values remained far from the hourly threshold. It should be noted that yesterday’s maximum hours were recorded in the stations on the east side of the island, with a specific hourly value of 102 micrograms / m3 at 4:00 p.m. at the La Grama station, which was significantly reduced in the following hours. The hourly records of the last 24 hours have been kept far from the hourly threshold (established at 350 micrograms / m3) in all the stations of the island. Throughout this morning, values around 100 migrograms / m3 have been registered in Puntagorda at 09:00 and in San Antonio at 04:00, whose evolution will have to be monitored in the next few hours.
With respect to particles smaller than 10 microns (PM10), the values measured in the set of stations continued at high levels, according to the trend already detected since last Saturday, and as a consequence of the entry of a Saharan air mass. Thus, yesterday there were exceedances of the daily threshold (established at 50 micrograms / m3) at all stations on the island of La Palma. The exceedances of the daily PM10 threshold are being generalized in other stations of the air quality measurement network located in the rest of the islands, associated with the aforementioned Saharan air intrusion.