SANTA CRUZ DE TENERIFE, Oct 4 (EUROPA PRESS) –
The Pevolca Steering Committee has agreed to reinforce the monitoring and surveillance work after the appearance of more fluid lavas as a result of the collapse of part of the La Palma volcano, which could lead to changes in the direction of the streams that would force new measures to be taken of civil protection.
This has been reported by the technical director of Pevolca, Miguel Ángel Morcuende, who explained that the collapse and destruction that occurred late in the afternoon yesterday of a part of the volcanic cone has produced an enormous contribution of very fluid lava and a “spike” increase in explosiveness.
Morcuende has pointed out that the eruptive activity continues to be strombolian with certain characteristics of fluid lavas that may be Hawaiian in nature, which is why they are being monitored and monitored, given that this type of fluid pouring could lead to some change in the direction of the streams. current casts.
The technical director warned that if this finally happened, it would force other civil protection measures to be taken to safeguard the safety of the people who could be affected by this variation in the course of the flows.
For her part, the spokesperson for the Pevolca Scientific Committee and director of the IGN in the Canary Islands, María José Blanco, pointed out that it has been verified, through satellite images, the existence of lava tubes that are facilitating rapid access of the lava to lower levels, but following the courses that are established right now.
Likewise, María José Blanco explained that the strombolian mechanism that is taking place in La Palma has a mixed and alternate character and simultaneously phases with the explosiveness produced by pyroclastic deposits and also more effusive phases produced by lava flows.
In turn, it has introduced a new concept to this volcanological phenomenon, such as the Volcanic Explosivity Index (VEI), which is used to quantify the magnitude of the explosiveness of an eruption and uses a scale as a measure. ranging from 0 to 8. In the case of the La Palma eruption, the assigned value is 2.
On the other hand, he reported that the casting that began on October 1 continues to show few signs of activity and at this time several active centers are observed inside the main crater and two located in the northwest of the side of the cone, one of the which suffered the collapse of a side at 7:45 p.m. yesterday.
When part of the wall was broken, a spill of the material that was contained has occurred, which was a lava lake, generating a large volume emission and extension of lava along the main cone and in turn dragging large blocks of the cone. The appearance of new emission centers in the environment of the existing cone is not ruled out.
Yesterday afternoon there was an increase in the frequency and intensity of the explosive activity, with durations of several minutes verifying the emission of ballistic mouths with a range of up to 800 meters, which means within the exclusion radius, which has been brought to the attention of scientists and emergency personnel in the area.
As for the lava delta, which already measures 32.7 ha, yesterday’s data showed an area that exceeds 29 ha. The marine plume continues at the contact edge of the lava delta, producing clouds of water vapor and hydrochloric acid that are concentrated in the contact environment. Likewise, the eruptive process may show episodes of increased and decreased strombolian activity, as well as pulses of phreatomagmatic activity.
HEIGHT OF THE ASH AND GASES COLUMN.
The height of the ash and gas column measured this morning was 4,500 meters. Thus, the wind is expected to carry the ash plume and sulfur dioxide to the south-southwest of the eruptive focus. The area most affected by the ash fall would be the south-southwest slope of the island of La Palma. This provision of the plume is favorable for the operation of the Canarian airports. The entry of a humid maritime air mass will decrease atmospheric stability, favoring air quality.
The seismicity continues as in previous days, maintaining a pattern that spatially overlaps with those that existed on September 11 and 12, at the beginning of this eruptive crisis, and maintaining a depth of around 10-15 km. Earthquakes at depths greater than 20 km are recorded as in previous days. In the last 24 hours dozens of events have been located, the maximum of magnitude 3.7 felt with an intensity III-IV. The increase in the number of earthquakes and their magnitude may indicate an increase in the probability that more felt earthquakes will occur, which may cause small landslides in sloping areas.
Regarding the emission of SO2 in the volcanic plume, the values measured yesterday reached 16,000 tons per day, a value higher than the previous day. Likewise, the diffuse emission of CO2 throughout the Cumbre Vieja area shows a value of 1,718 tons per day. Low CO2 values continue to be maintained in terms of air quality in all stations on the island, except for specific peaks in Los Llanos and El Paso, but of low intensity and far from the thresholds established in the regulations in force. Regarding particles less than 10 microns, lower values were measured compared to indoor days, although the daily threshold was once again exceeded at the Los Llanos station, with an average of 96 micrograms / m3.