Mayon Volcano Situation Report No. 3 31 January 2018 Situation Overview Jan. 13, 2018 – PHIVOLCS raised Alert Level 1 (abnormal) when Mayon Volcano generated a steam-driven explosion (eruptions caused by groundwater flashing to steam as it is heated by magma), producing high grayish ash plume. Jan. 14, 2018 – Alert level is raised to...