Ed Laguerta, Phivolcs resident volcanologist, said the downgrade in Mayon’s alert status was the result of seven weeks of continuing decline in the volcano’s unrest.
Phivolcs raised alert level 2 on Oct. 11, 2003.
Laguerta said the number of earthquakes has dropped while the sulfur ash emission has reached less than 500 tons a day.
He added that a ground deformation survey conducted from Feb. 26 to March 11 showed a marked deflation of Mayon’s edifice, indicating the absence of an active magma ascent.