Manila, June 21 -- An increase in seismic activity or volcanic earthquakes caused by movements or eruptions of magma from the volcano has been observed anew in Mount Bulusan. The Philippine Institute of Volcanology and Seismology (Phivolcs) on Tuesday reported that 80 volcanic earthquakes have been recorded in Bulusan over the past 24 hours. The figure is much higher compared to only one volcanic quake recorded the previous day. Late Monday, the Phivolcs said 65 volcanic quakes, including one low-frequency volcanic quake, were recorded in Bulusan from 5 a.m. to 11:45 p.m. While most of the recorded quakes were weak and shallow events, Phivolcs said this still indicates that a phreatic eruption could occur within the next few hours to the ne...