Volcanologists closely monitoring the activities of Mayon Volcano are wary of the calm before the storm.

With past eruption records in mind, volcanologists here are becoming more fidgety with the sudden lull of Mayon Volcano following its awesome two-day display of fireworks, saying it could serve as a prelude to the anticipated big bang.

Resident volcanologist Ed Laguerta said they are relying on the previous eruption records of Mount Mayon in doing away with any recommendation for the more than 47,000 evacuees to return home.

"We already learned our lesson in the past. Every affected resident here knows that the silence of Mayon is not an assurance that they would be safe if they go back home," said Laguerta.

Laguerta is particularly referring to the 1984 Mayon Volcano major relaxing when a series of loud explosions occurred, coupled with the sudden gush of some 70 million cubic meters of pyroclastic materials from Mount Mayon.

"Fortunately, there were no casualties reported on that incident but it now serves as a lesson for both the residents and us that physical observation of Mount Mayon is not enough to predict what would happen next," said Laguerta.

This was likewise echoed by Cedric Daep, Albay Provincial Disaster and Coordinating Council (PDCC) head, saying they coordinate more with other government agencies once a lull in activities would be monitored.

"Mas lalo kaming naghahanda kapag biglang nanahimik ang Mayon kasi baka nag-iipon lang 'yan ng lakas at biglang sumabog," said Daep.

On Saturday, Mayon Volcano dumped a huge volume of ash in the western side of the volcano covering some barangays of Guinobatan, Camalig, and Ligao City.

But Laguerta said the reported ash cloud that rained over the three areas do not entirely come right from the crater of the Mayon Volcano, saying they are an accumulation of ash deposits in the slopes and the slight ash puffs recorded yesterday.

"The direction of the wind is heading toward those areas, so it is an expected phenomenon brought by the northeast monsoon (amihan)," said Laguerta.

Aside from the previous eruption records of Mayon, volcanologists here are heavily relying on the monitoring instruments they put up around the volcano due to the cloud formation around it.

And based on these instruments, it was recorded that there were only 33 ash explosions since Friday until 7 a.m. yesterday and 26 rumbling sounds compared to nearly 100 ash puffs and more than a hundred booming and rumbling sounds in the past few days.

From as high as two kilometers of ash explosion on December 24, Phivolcs reported that the ash explosions only went as high as one kilometer yesterday.

Laguerta, however, said that they recorded a significant increase in the emission of sulfur dioxide from nearly 2,000 tons a day on December 24 to nearly 9,000 tons a day.

"So we cannot say at this point that it is already safe for evacuees to go back home, we still have to monitor and monitor," said Laguerta.

Asked if that would mean evacuees will have to spend their media noche in evacuation centers, Laguerta said: "Definitely."