Date:         Thu, 2 Feb 1995 12:44:31 MST
From: Global Volcanism Network 
Subject:      Bulusan activity, Jan 1995

The following reports about recent activity at Bulusan were received from PHIVOLCS.  See the last two GVN Bulletins (Nov & Dec 1994) for additional information.

Date: 23 Jan 95

Another phreatic eruption occurred at Bulusan on 21 Jan 1995 2237H (local
time).  Activity was difficult to see apart from lightning flashes over the
summit and light ashfall over the San Benon Observatory, about 5 km SW of
active crater.  Based on the seismic record, the 21 Jan event was fairly
strong but ash deposits measured later that day showed the overall amount
to be similar to previous ash emission (1 to 2 mm, 7 km downwind).
Rumbling reportedly accompanied the ash ejection.

Alert Level 2 was maintained over Bulusan and surrounding villages.  This
is a warning of heightened volcanic activity but is non-commital with
respect to the timing of future events.  This is because seismic and ground
deformation parameters have not reflected the short-lived ash
eruptions.  As before, COSPEC could not be undertaken because of
heavy cloud cover.  However, one thing is for sure-- the interval between
this latest ash eruption and the previous has increased, and a similar but
more subtle trend is perceivable for the more major events for this month.
This may be taken as an indicator of decreasing activity, together with the
very low seismicity and unremarkable ground deformation.

No crop damage or other damage to villages have been reported nor there
have been anybody reportedly hurt as a result of these eruptions.  The
current alert level advises against anyone visiting within 4 km of the

Date: 1 Feb 95

Bulusan Volcano spewed ashes again on 28 January at 1433 H(local time). The
event was recorded by the local seismic network as an explosion type
earthquake. The explosion produced a 2-km high ash cloud above the
summit craters and deposited andesitic ash (3 mm max) on villages up to
15 km downwind.  This event, as before, was preceeded by low and
unremarkable local seismicity and little else on other monitored
parameters. Most earthquakes and short-duration tremor have
occurred after each explosion.  Ground deformation was at background levels

Because no escalating activity has been detected, there has been no change
in the prescribed danger zone which stands at the 4 km radius. No
evacuation is therefore recommended.  No damage resulting from this event
has been reported.

Ernesto G. Corpuz             | Tel. (632) 712-6110
Volcano Monitoring Division   | Fax  (632) 712-4656
Phil. Inst. Volcanol. Seismol |
29 Quezon Ave. Q.C. 1100 Philippines