The government, meanwhile, assured residents that evacuation plans were in place in case of a major eruption. Authorities for the time being ruled out raising the alert level from two notches below the highest.
Authorities, on the other hand, have extended a six-kilometer danger zone around the peak of the volcano to seven kilometers on the southeastern slope, where most of the lava and other debris have been rolling down.
Despite this, it was business as usual on the streets of Legazpi City, the capital of Albay, near the volcano.
People went about their lives during daytime and in the evenings, residents and tourists gathered at a hillside to gaze at the flowing lava.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said sightseers could still view Mt. Mayon’s fiery lava flow from a safe distance of 12 to 15 kilometers away.
"The current activity is still substantially quiet, non-explosive type," Phivolcs Director Renato Solidum said, adding that the best view of the 8,118-foot mountain, famous for its near-perfect cone, could be seen at the center of Legazpi City and Daraga in Albay.
The silent, steady flow of lava and debris on Mayon has reached 800 meters down the summit since Friday, Phivolcs said.
Gleaming in the dark and steaming during the day, the advancing lava and cascading rocks were accompanied by 314 tremors in the past 24 hours, significantly higher than the 111 tremors the previous day, Phivolcs noted.
"The increased seismic activity, relatively fast lava extrusion rate and high sulfur dioxide emission rate indicate heightened unrest of the volcano, which could lead to explosive eruption," the institute said.
Officials had earlier estimated a hazardous eruption could occur within weeks.
According to disaster control officials who made an ocular inspection of the area, families living near the six-kilometer radius danger zone have started packing their belongings, as lava continuously flowed from the volcano’s summit crater on the southeast towards Bonga Gully from 6:43 Sunday evening until 3:58 a.m. yesterday.
Bonga Gully faces Legazpi City and the towns of Sto. Domingo, Daraga and Camalig.
As of Sunday, sulfur dioxide emission rate of the volcanic plume was measured at 1,513 tons per day, compared to 2,211 tons recorded per day on July 15 this year.
Press Secretary Ignacio Bunye Jr. assured the people yesterday that the National Disaster Coordinating Council (NDCC) and local authorities "are on top of all disaster preparedness measures to ensure the safety of the residents who may be directly affected by the volcanic activity."
In the event of an eruption, the Office of Civil Defense (OCD) said government agencies and the military were prepared to carry out mass evacuations and contingency plans were in place.
OCD administrator Glenn Rabonza yesterday assessed preparations for evacuation of some 1,484 families, or 7,436 persons, in the province if alert level 4 on Mayon is raised.
"We would also like to know how we will prepare at the national level to support the preparations being undertaken by the PDCC (Provincial Disaster Coordinating Council) when there will be evacuation or emergency operations," Rabonza said.
"There must be an organization and a plan without which funds would go for naught," he noted, as he lauded the Albay PDCC for being one of the best organized disaster operation groups in the country.
Rabonza also checked on the capabilities of the regional health and social welfare offices in supporting thousands of possible evacuees.
Saying there are no gaps in local preparations, Arnel Capili, director of the OCD in the Bicol Region, said the NDCC would step in to aid them in case of a "prolonged eruption."
"NDCC will come in if there is a shortage in the provisions for the evacuees if a prolonged eruption takes place," Capili told The STAR.
Cedric Daep, head of the provincial disaster management office, said there is an ongoing review of the evacuation scenario with the PDCC and the different cities and municipal disaster coordinating councils in the province.
There are 35 school buildings that can be immediately turned into evacuation centers. Tabaco City has three evacuation centers; Malilipot, two; Sto. Domingo, three; Legazpi City, eight; Daraga, seven; Camalig, eight; Guinobatan, one; and Ligao City, two.
Amid fears of a near eruption, Phivolcs resident volcanologist Ed Laguerta pointed out that the volume of lava that oozed out of Mayon was still small and a remnant of its eruption in 2001.
"The volume of lava extruded is between 500,000 and one million cubic meters," explained Laguerta, adding that this was small compared to the lava volume inside the volcano’s conduit.
"So hindi pa nauubos yung nanduon sa conduit na remnants. So hindi pa puputok dahil wala pa itong gas content. Ang nagpapaputok ng isang bulkan ay yung gas content ng magma (The volume of lava inside the conduit has not yet been totally extruded. Therefore, the volcano cannot yet erupt because it has no gas content. What triggers the volcano to explode is the gas content of the magma)," explained Laguerta.
Mayon’s most violent eruption, in 1814, killed more than 1,200 people and buried Cagsawa town in mud. A 1993 eruption killed 79.
The Philippines is in the Pacific "Ring of Fire," where volcanic activity and earthquakes are common.
In 1991, Mount Pinatubo in Zambales exploded in one of the world’s biggest volcanic eruptions of the 20th century, killing about 800 people.
Dr. Julio Salazar, assistant provincial health officer, said they were assessing facilities and supplies such as water, toilets as well as an inventory of medicines and vaccines and chlorine.
Salazar added that the provincial health office is activating the Municipal Emergency Response Team (MERIT) to have a 24-hour rescue team on standby.
Yolanda Guanzon, head of the provincial social welfare and development office, said that she has already submitted to Gov. Fernando Gonzales the purchase order of relief goods, rice and other goods needed for evacuees. — AP, Celso Amo, Cet Dematera, Helen Flores, Sheila Crisostomo, AFP