Scientists from PHIVOLCS conducted an aerial investigation of Bulusan and discovered lahar deposits and three steaming fissures. Scientists also observed steam plumes that rose to altitudes of 1.6-1.7 km.

PHIVOLCS reported on 20 May that seismicity from Bulusan remained high following the explosion on 12 May. Ground deformation measurements conducted on 17 May on the NE flank revealed 4 mm of inflation compared to the previous measurement on7 April. The Alert Level was raised from 1 to 2 (out of 5) due to the increased seismicity and inflation.

An explosion from Bulusan on 12 May produced an ash plume that rose to an altitude of 5.6 km (18,400 ft) a.s.l. and drifted WSW and WNW. The activity was accompanied by rumbling sounds and was recorded by the seismic network as an explosion-type earthquake that lasted about 35 minutes.

After 3 montsh of relative quiet, Bulusan had another (probably phreatic or phreatomagmatic) eruption today, Easter Sunday. The eruption lasted for 20 minutes and produced an ash colum that rose 2,5 km into the sky.

PHIVOLCS reported that an explosion from the summit of Bulusan on 24 January lasted about 10 minutes based on seismic interpretation. Observation was inhibited due to cloud cover. Ashfall was reported from areas SW.

As PHILVOLCS reports an ash explosion occurred at Bulusan Volcano at 1:09 am local time on 20 December 06. The explosion was not observed dur to thick clouds, but clearly recorded as seismic signals, rumbling sounds and lightning flashes that lasted for about 20 minutes.

PHIVOLCS reported an explosion from Bulusan on 19 October. The following day, steam plumes drifted W and WSW. On 23 October, an explosion produced a brownish ash plume that rose to about 2.6 km (8,400 ft) a.s.l. and drifted SE and SW.Light ashfall (trace to 0.5 mm thick) from both explosions was reported from neighborhoods in the municipality of Irosin.

Bulusan had another phreatic explosion on Thursday 19 Oct, 2006, at 18h44 local time, emitting an ash plume rising to 3-4 km elevation.

A new eruption took place the  morning of 10 Oct at Bulusan volcano causing ash fall up to 5 mm of thickness in the area of Irosin and Bulan.

Bulusan stratovolcano has a new eruptive episode yesterday 10 Oct, 2006, at 17h15 local time and produced an ash cloud reaching 3 km altitude that drifted towards the villages of Casiguran, Irosin and Bulan.
Since its reawakening on 21 March 2006, Bulusan has had 10 eruptions producing ash fall in the surrounding areas. On 24 June, a large lahar (=mud flow) travelled down the slopes of the volcano.

PHIVOLCS reported that steam plumes from Bulusan reached up to 350 m above thesummit (6,300 ft a.s.l.) on 30 August and 1 September. The plumes drifted NW andSE, respectively.

On 29 July, PHIVOLCS reported that the Alert Level at Bulusan was lowered from 2 to 1 (out of 5 levels) due to a gradual decrease from 28 June of all monitored parameters to near-baseline levels. 

According to PHIVOLCS, an ash-and-steam cloud from Bulusan on 7 June reached aheight of approximately 2 km above the summit (11,700 ft a.s.l.) and drifted N and NW. Light ashfall was reported 5 km N and trace amounts as far as 20 km N.The Alert Level was raised to 2 (scale 0 to 5), which means restricted entry within 4 km of the summit. On 10 June, an ash-and-steam cloud reached a height of ~1 km above the summit (8,400 ft a.s.l.) and drifted N and NE.  A newsarticle reported one death caused by an asthma attack from exposure to ash.

PHIVOLCS reported that an ash-and-steam cloud emitted from Bulusan on 31 May reached a height of 1.5 km above the summit (10,100 ft a.s.l.). Light ashfall,from trace amounts to 1.5 mm thickness, fell in areas W and NW of the volcano.Bulusan remained at alert Level 1, with a permanent danger zone of 4 km around the summit.

Bulusan volcano had a small eruption this morning at 08h17 local time, producing an ash plume at 3 km altitude drifting SW (Source : VAAC Tokyo)

Bulusan volcano erupted on Sat. 29 April 2006 at 10:44 am (0244 GMT) spewing a column of ash about 1.6 km high. Ash fall occurred in surrounding villages. There were no reports of casualties or damage.

Bulusan volcano in the Philippines came back to life on Tuesday 21st of March 2006. At around 23h00 local time (16:00 GMT) the volcano spewed a column of ash nearly a mile (1.5 kilometres) into the sky. The Philippine Institute of Seismology and Vulcanology (Phivolcs) said the ash was unlikely to cause any harm, but warn that the volcano may be about to erupt more powerfully. A four-kilometer (2.4-mile) exclusion zone is already in place around the 1,565-meter (5,133-foot) volcano, which is 600 kilometers (370 miles) southeast of Manila. The institute will be closely monitoring the volcano for further activity. Bulusan had a series of similar explosions in 1994 and 1995.