Taal is quiet but volcanic activities continue underneath
Published Feb 5, 2020 12:00 am
By Alexandria Dennise San Juan
Lower sulfur dioxide emission and fewer volcanic tremors were observed in Taal Volcano on Wednesday, but state volcanologists warned that volcanic activities continue underneath.
The main crater of the Taal Volcano is seen during an aerial survey done by government officials, more than a week after the eruption of Taal Volcano in Batangas. (Mark Balmores/ MANILA BULLETIN)
The Philippine Institute of Volcanology and Seismology (Phivolcs) said that activity in Taal's Main Crater has been characterized by weak emission of steam-lade plumes reaching only from 50 to 100 meters tall.
Compared to the sulfur dioxide (SO2) level of 231 tons per day recorded on Monday, the emission of SO2 slightly dropped on Tuesday and was measured at an average of 55 tons per day.
A decline in the number of volcanic quakes was also noted by state volcanologists from Tuesday morning to Wednesday morning as the Taal Volcano Network plotted 156 temblors including two low-frequency events and 18 harmonic tremors having durations of one to three minutes.
The latest recorded earthquakes were lower than the 223 volcanic quakes observed from Monday to Tuesday.
The continuous occurrence of earthquakes within Taal Volcano, Phivolcs said, signifies magmatic activity beneath the Taal edifice that could lead to eruptive activity at the Main Crater.
Alert Level 3 remains over Taal Volcano, which means there is a "relatively high unrest manifested by seismic swarms including the increasing occurrence of low-frequency earthquakes and/or harmonic tremors where some events are felt."
Phivolcs downgraded Taal's danger status from Alert Level 4 to Alert Level 3 on January 26, two weeks after its phreatic or steam-driven eruption which forced thousands of nearby residents to evacuate due to thick ash that blanketed their homes.
Despite the lowering of Taal's alert status, the state volcanology agency reminds the public that sudden steam-driven and even weak phreatomagmatic explosions, volcanic earthquakes, ashfall, and lethal volcanic gas expulsions can still occur and threaten areas within the volcano island and nearby lakeshore communities.
With this, Phivolcs warned the public that entry into the Taal Volcano Island as well as into areas over Taal Lake and communities west of the island within a seven-kilometer radius from the Main Crater must be "strictly prohibited."
Local government units were also advised to assess areas outside the danger zone for damages and road accessibilities and to strengthen preparedness, contingency and communication measures in case of renewed unrest.
Residents were also asked to observe precautions due to ground displacement across fissures, frequent ashfall, and minor earthquakes.
Communities beside active river channels, particularly where ash from the main eruption phase has been thickly deposited, should increase vigilance when there is heavy and prolonged rainfall since the ash can be washed away and form lahars along the channels.
The main crater of the Taal Volcano is seen during an aerial survey done by government officials, more than a week after the eruption of Taal Volcano in Batangas. (Mark Balmores/ MANILA BULLETIN)
The Philippine Institute of Volcanology and Seismology (Phivolcs) said that activity in Taal's Main Crater has been characterized by weak emission of steam-lade plumes reaching only from 50 to 100 meters tall.
Compared to the sulfur dioxide (SO2) level of 231 tons per day recorded on Monday, the emission of SO2 slightly dropped on Tuesday and was measured at an average of 55 tons per day.
A decline in the number of volcanic quakes was also noted by state volcanologists from Tuesday morning to Wednesday morning as the Taal Volcano Network plotted 156 temblors including two low-frequency events and 18 harmonic tremors having durations of one to three minutes.
The latest recorded earthquakes were lower than the 223 volcanic quakes observed from Monday to Tuesday.
The continuous occurrence of earthquakes within Taal Volcano, Phivolcs said, signifies magmatic activity beneath the Taal edifice that could lead to eruptive activity at the Main Crater.
Alert Level 3 remains over Taal Volcano, which means there is a "relatively high unrest manifested by seismic swarms including the increasing occurrence of low-frequency earthquakes and/or harmonic tremors where some events are felt."
Phivolcs downgraded Taal's danger status from Alert Level 4 to Alert Level 3 on January 26, two weeks after its phreatic or steam-driven eruption which forced thousands of nearby residents to evacuate due to thick ash that blanketed their homes.
Despite the lowering of Taal's alert status, the state volcanology agency reminds the public that sudden steam-driven and even weak phreatomagmatic explosions, volcanic earthquakes, ashfall, and lethal volcanic gas expulsions can still occur and threaten areas within the volcano island and nearby lakeshore communities.
With this, Phivolcs warned the public that entry into the Taal Volcano Island as well as into areas over Taal Lake and communities west of the island within a seven-kilometer radius from the Main Crater must be "strictly prohibited."
Local government units were also advised to assess areas outside the danger zone for damages and road accessibilities and to strengthen preparedness, contingency and communication measures in case of renewed unrest.
Residents were also asked to observe precautions due to ground displacement across fissures, frequent ashfall, and minor earthquakes.
Communities beside active river channels, particularly where ash from the main eruption phase has been thickly deposited, should increase vigilance when there is heavy and prolonged rainfall since the ash can be washed away and form lahars along the channels.