The lava causes overflows in the volcanic tubes, but does not push the fronts that are standing
This “clear change in dynamics” was also reflected in seismicity. And it is that the number of movements detected by the National Geographic Institute (IGN) stations were reduced to less than 50 during the day yesterday, the lowest figure in the last month and half that of last Wednesday. To this was added a lower power since there was no earthquake with a magnitude greater than 4. In any case, López highlighted that there is a variability in this parameter due to the “internal readjustment process” of the volcano, which leads it to cause earthquakes of magnitude 4.5, such as the one that occurred at 11:05 p.m. on Thursday, at a depth of 35 meters in the municipality of Mazo, which was felt with intensity IV (widely observed) throughout the island.
The air quality in Los Llanos is still “extremely unfavorable” due to the presence of ash
López said that, like seismicity, the emission of volcanic material from the different mouths does not show a “very intense continuity”, but it does produce “pulses” that have caused overflowing of the lava tubes. “There is still lava, but not with the intensity that was seen in some moments because otherwise the wash fronts would be moving”, which since last Tuesday have been standing at the same point without causing further damage. This ejected material, he explained, is responsible for filling “small cavities.”
Seismographs record the fewest number of earthquakes in the last month
The tremor remains at “medium low” levels, according to the daily IGN report, with a downward trend since noon last Tuesday. During the last 24 hours, the tremors registered in the volcanic tubes through which the magma rises continue with levels prior to October 24, with an “oscillatory behavior” that leads them to show upward impulses at times, according to the director of the Institute. National Geophysicist.
The parameter that showed the greatest variation on Thursday’s session was the emission of sulfur dioxide (SO2) in the volcano’s plume, which rose again considerably to 31,300 tons, the highest value in the last 12 days. and that breaks downward behavior. However, yesterday the volcano showed a “low intensity” in terms of its explosiveness, but an “intense degassing” that was visible from the Aridane Valley, as stated by López. The Pevolca scientific committee reported that, despite this increase, “the temporal evolution of SO2 estimates from satellite data reflects a downward trend since September 25”.
IGN detects increased degassing and decreased explosiveness
Another novelty was a slight vertical deformation of the terrain in the Jedey area, where the station closest to the volcano is located. This parameter on previous occasions has preceded an increase in volcanic activity, such as the one that occurred on October 26 after rising 10 centimeters. The following two days the number of earthquakes increased considerably, with an average of close to 200 tremors every day, and a subsequent advance of the lava flows that destroyed the last houses that were left standing in the Todoque neighborhood. In any case, Carmen López added that we must wait for an evolution in the next few hours to assess how it could affect the eruptive process.
While the volcano continues with a stable behavior, the air quality continues “extremely unfavorable” for the inhabitants of Los Llanos de Aridane. Neither the trade winds nor the increase in the height of the thermal inversion have led to a decrease in particles smaller than 10 microns, the so-called PM10, which are associated with the presence of ashes in the environment. The mobile station installed in the center of the city once again registered “extremely unfavorable” values for health during Friday, which stood at around 200 micrometers, triple the recommended value of 50. The technical director from Pevolca, Rubén Fernández, yesterday ruled out requesting self-confinement to the population of this municipality “unless it gets very bad.” For now, the measures that have been taken are to recommend the use of FFP2 masks at all times, eliminate any physical activity in the open air and that people with respiratory or heart problems, minors, the elderly and pregnant women avoid going outside if it is not out of necessity.
This worsening of the air quality due to small particles, which has been detected since last Sunday, has caused that the students of the schools and institutes of Los Llanos de Aridane, El Paso, Tazacorte, Tijarafe and Puntagorda have not had face-to-face classes during every week. The Ministry of Education will decide during the weekend if the students continue with the lessons electronically or if they return to the classrooms in case the atmospheric conditions improve.
Likewise, the trade winds coming from the northeast, which push the plume towards the south and southwest, led to the permits to the residents of Puerto Naos, La Bombilla and El Remo to come to collect their belongings were suspended yesterday due to contamination and due to the difficulties present on the roads due to the accumulation of ash. Fernández commented that during this morning, both the meteorology and the state of the road will be evaluated to decide whether to resume the accompaniment of the evicted.
Another of the recommendations that the technical director of Pevolca made yesterday was related to the removal of volcanic sand from the roofs of the houses. Thus, he reviewed that all those neighbors who have roofs with one or two waters desist in their attempt to clean them due to the danger they entail in the event of possible falls. For this reason, Fernández ordered them to ask their respective municipalities for the action of the emergency services to take over this task. Likewise, he announced that work with heavy machinery is being planned to be able to extract the accumulated ashes in the surroundings of the houses, which in some cases reach 2 and 3 meters in height.
The technical director of Pevolca made a balance of the terrestrial connections devastated by the lava flows. A total of 63.8 kilometers of road have been buried by lava, with LP-213 (Puerto Naos – Los Llanos) as the most affected with 2.4 kilometers, followed by LP-2132 (Puerto Naos – Tazacorte, by La Costa) with 2.2; LP-2 (Los Llanos – Fuencaliente) with 2.1; LP-212 (Tacande) with 1.5; and LP-211 (Todoque) with 0.928. In addition, the buried streets amount to 9.6 kilometers, the crossings 1.9 and the so-called other roads 42.9.
Rubén Fernández pointed out that they continue with the works to widen the road that starts from the Valle Aridane Tennis Club to allow the arrival of high tonnage vehicles to Puerto Naos. This road is the only one that currently operates normally to connect this tourist town with the rest of the Island since the other access road, the LP-211, remains open but with restrictions due to the fact that laundry number 11 -la further south of all- it is only 100 meters away. In the event that it ends up swallowing it, Puerto Naos would be left with the narrow path of the sports facilities as the only access to enter and exit the Los Llanos de Aridane neighborhood, which would significantly hinder connections.
The spokesperson for the committee in charge of monitoring the evolution of the volcano recalled the measures that will be taken today on the roads closest to the eruption, between Los Llanos de Aridane and Tajuya, to avoid possible collapses of the roads and guarantee the safety of the pedestrians. Between 5:00 p.m. and 10:00 p.m., the LP-2 and LP-3 highways will be one-way uphill, while the Hermosilla highway will be used for the descents. High-tonnage vehicles will be able to use the general roads in both directions.
Fernández also stressed that periodic analyzes of groundwater are being carried out and that all of them have an “optimal” state.
- The number of sheltered by the eruption rose to 509 yesterday, six more than the previous day, of which 399 are staying at the Princess Hotel in Fuencaliente, 67 in the Aridane Valley of Los Llanos and 43 dependents in the health centers of the Cabildo of La Palma.
Magnitude of the earthquake
- The largest earthquake recorded during the last 48 hours rose to 4.5, which occurred last Thursday night and was felt by the population of the entire island of La Palma. During the day yesterday, no seismic movement greater than magnitude 4 was detected.
Miles of roads
- The Pevolca detailed yesterday the kilometers of roads that have been buried by the lava and that amount to 63.8. The two roads most affected are the LP-213 between Puerto Naos and Los Llanos (LP-213), with 2.4 kilometers, and the LP-2, which goes from Los Llanos to Fuencaliente, with another 2.2.
- The Cabildo de La Palma will begin to use heavy machinery to remove the ash that is accumulated next to the houses, which in some cases have mountains of 2 and 3 meters, as indicated yesterday by the technical director of Pevolca, Rubén Fernández, on the wheel press.
- Air quality in Los Llanos de Aridane continues to be “extremely unfavorable” for the sixth consecutive day due to high PM10 values, related to ash expulsion. In yesterday’s session, 200 micrometers were reached, three times more than recommended.