SANTA CRUZ DE TENERIFE, Oct 7 (EUROPA PRESS) –
The technical director of the Pevolca Steering Committee, Miguel Ángel Morcuende, based on the data collected by the Scientific Committee and as a result of the successive earthquakes that are occurring in municipalities such as Villa de Mazo and Fuencaliente, has insisted that the possibility that an emission center may arise outside the vicinity of the main cone is “very rare” and “not likely”.
Miguel Ángel Morcuende has indicated at a press conference that the number of seismic events that have been recorded continues to decrease or remain and is occurring at high depths, even 35 kilometers. Therefore, he reiterated that at this time there is “no data” that suggests that there may be a new emitting center due to the current conditions of seismicity and deformation and pressure of the ground.
The spokesperson for the Pevolca Scientific Committee, María José Blanco, has clarified that these new earthquakes, some of which have exceeded the magnitude of 4 (mbLg), are a consequence of the existence of a feedback mechanism and readjustment of the active volcanic system, and rules out that it has to find a new outlet to the surface, so that “to this day there is no data that suggests that an emission center can be opened at a distance from the one currently active”.
However, a meeting has been called with residents of the Fuencaliente municipality, according to Miguel Ángel Morcuende, because there has been “some concern” among the population, which is feeling the tremors. Thus, in this meeting, the intention is to launch a message of tranquility and inform what should be done in case an evacuation is necessary.
REPORT OF THE SCIENTIFIC COMMITTEE.
According to the daily report of the Pevolca Scientific Committee, the fissure eruption continues with its strombolian mechanism, alternating and combining phases of more explosiveness with the production of pyroclasts with more effusive phases with the production of lava flows. The Volcanic Explosivity Index (VEI) remains at 2.
At least three emission centers are still active in the main crater and one on the north side of the cone. The appearance of new emission centers around the main cone is not ruled out. Lava tubes have been built that favor drainage from the main emission center to the sea and a decrease in degassing and temperature is observed in the area of fissures described in yesterday’s report.
The lava delta or fajana continues its growth fed from several points, extending in a north-south direction. This morning a branch of the stream that ran further south reached the lava delta from the 1949 eruption, between Los Guirres beach and El Charcón.
The marine plume continues along the edge of the lava delta, producing clouds of water vapor and hydrochloric acid that concentrate in a small volume around the contact. The observed effect of the lava delta on the water column of the marine environment, both in physical-chemical and biological parameters, reaches depths of 250 meters and a distance of 500 meters from the front of the lava delta.
The morphology of the cone changes repeatedly due to the successive processes of growth and reconfiguration, and the eruptive process can show pulses of increase and decrease in strombolian activity, with pulses of phreatomagmatic activity. Likewise, the height measured today of both the ash and gas column and its dispersion reaches 3,200 meters.
Regarding the meteorological conditions, they are unfavorable from the air quality point of view due to the presence of a marked thermal inversion with a base located around 600-700 meters that acts as a cover. This investment, together with the predominance of weak winds, hinders the dispersion of pollutants on the west slope of La Palma, mainly in poorly ventilated areas.
The wind at levels between 1,500 and 5,500 meters will continue for the next few hours with the predominant direction of the west component. This wind distribution disposes the ash plume and sulfur dioxide (SO2) in an east-west direction from the eruptive focus. All of the above has a direct influence on the operation of La Palma Airport due to the fall and accumulation of ash. This situation will continue until next Saturday, October 9.
SEISMICITY.
Seismicity continues to be located mainly close to the seismicity of the first days, September 11 and 12, at depths between 10 and 15 km. In addition, earthquakes located at depths greater than 20 km have been recorded with an increase in the value of their magnitudes. In the last 24 hours, the number of earthquakes and the maximum magnitude observed have increased. The largest, of magnitude 3.9, felt with intensity III-IV, was registered yesterday, but this morning an earthquake occurred at 12.17 hours, with a magnitude of 4.3, which has been felt with intensity III practically in the entire island. from La Palma.
The deformations at the stations closest to the eruptive center do not show any significant pattern.
During yesterday the SO2 emission associated with the volcanic plume continued to register high values in line with the ongoing eruptive process, reaching values of 13,100 tons per day. Likewise, the diffuse emission of carbon dioxide (CO2) measured yesterday associated with the emission of the entire Cumbre Vieja reached the value of 1,596 tons per day. The diffuse emission of CO2 at the Los Llanos station reflects that it has a deeper origin than that measured at the Fuencaliente station. These measures are consistent with the current eruptive process.
Likewise, yesterday, Wednesday, the SO2 values remained at low levels as in previous days, except for a specific episode in El Paso and Los Llanos at 10:00 am, which was remitting throughout the day. During the night and early hours of this morning, there has been a very intense increase in SO2 concentrations at the Tazacorte, Los Llanos and El Paso stations, being more intense in El Paso, where a maximum hourly value of 667 micrograms / m3 at 0700 hours, exceeding the alert threshold established at 500 micrograms / m3 on two consecutive occasions. During that episode, which began at 03:00 and currently seems to be subsiding, the SO2 hourly threshold has been exceeded five times in El Paso, one in Tazacorte and two in Los Llanos.
Regarding particles smaller than 10 microns (PM10), no significant events have occurred and the measured concentrations are below the thresholds, except at the La Grama station, in Breña Alta, where an abnormally high value was produced in compared to nearby stations yesterday morning. This event seems to be related to the cleaning of roads in the area, which causes the re-suspension of particles, so that an exceeding of the threshold cannot yet be considered until it is ruled out that it is due to said cleaning. During the early hours of today, an increase in PM10 particles is observed at the Los Llanos station, although it seems to be subsiding.
