Minor eruption, quakes break Taal Volcano’s weekend calm
LUCENA CITY—Taal Volcano in Batangas province stirred from a period of calm over the weekend after registering renewed seismic activity and a minor phreatomagmatic eruption, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported.
In its bulletin issued on Sunday morning, Phivolcs said the volcano recorded eight volcanic earthquakes over the past 24 hours, accompanied by six volcanic tremors lasting between five and 23 minutes.
A day earlier, the agency reported five volcanic earthquakes and four volcanic tremors.
Phivolcs explained that volcanic earthquakes are generated by processes occurring within an active volcano and are identified by their distinct arrival patterns, amplitudes and wave periods. Volcanic tremors, on the other hand, are continuous low-frequency seismic signals with regular or irregular waveforms.
On Friday afternoon, Phivolcs reported a minor phreatomagmatic eruption at the summit crater, consisting of four eruptive pulses that lasted about two minutes, based on seismic and camera monitoring.
“The event generated short, dark ash jets that collapsed back into the main crater lake, along with light gray to whitish plumes that rose up to 600 meters above the crater before drifting southwest,” the agency said.
A phreatomagmatic eruption occurs when magma comes into contact with water, triggering explosive activity that produces steam, ash and fragmented volcanic material.
Still calm
Despite the eruption and renewed seismic activity, Taal Volcano has generally remained quiet this month.
Phivolcs monitoring data showed that from Dec. 1 to Dec. 28, the volcano recorded a total of 84 volcanic earthquakes and 22 tremor episodes. No seismic events were logged from Dec. 10 to Dec. 13, Dec. 15 to Dec. 21 and again from Dec. 24 to Dec. 26.
Three minor phreatomagmatic eruptions were also recorded during the month.
In contrast, volcanic activity was significantly higher in November, when Taal registered 514 volcanic earthquakes and 98 tremors. On Nov. 22 alone, 128 volcanic earthquakes were recorded in a single day. Two phreatomagmatic eruptions also occurred during that month.
These figures exceeded October’s 367 earthquakes and 69 tremors. Three phreatomagmatic eruptions and one phreatic burst were also recorded.
A phreatic eruption occurs when water comes into contact with hot rocks or gases, producing steam-driven explosions without direct magma involvement.
In its latest bulletin, Phivolcs reported sulfur dioxide emissions of 150 metric tons, with gas plumes rising only up to 20 meters.
No upwelling of hot volcanic fluids was observed in the main crater lake of Taal Volcano island, located at the center of Taal Lake and no volcanic smog, or “vog,” was detected during the monitoring period.
Taal Volcano remains under alert level 1, indicating a low level of volcanic unrest.
Phivolcs reiterated that alert level 1 means the volcano is still in an “abnormal condition” and should not be interpreted as having ceased unrest or the potential for eruptive activity.
Taal last erupted explosively in January 2020, forcing the evacuation of hundreds of thousands of residents within the 14-kilometer danger zone.
Located in the middle of Taal Lake, Taal Volcano is the country’s second most active volcano, with 38 recorded historical eruptions. Mayon Volcano in Albay province remains the most active, having erupted more than 50 times in the past 500 years.
