After the ash explosion of 01 September, a general decline in the overall
activity of Mayon has been established. The decrease in key parameters such
as seismicity, gas (Sulfur Dioxide) emission rates and ground inflation all
indicate a waning condition. The slowdown in the eruptive activity is also
evident from the decrease in intensity of crater glow and the diminishing
volume of lava being extruded from the summit.
In view of the foregoing decrease in the tempo of unrest, PHIVOLCS is
lowering the alert status of Mayon Volcano from Alert Level 4 to ALERT
LEVEL 3. This means a diminished probability for a hazardous major
eruption. Corollary to this announcement, PHIVOLCS also recommends smaller
exclusion zones defined by the following:
-
For areas previously
declared off-limits up to 8 kilometers from the summit, the new Extended
Danger Zone (EDZ) is now reduced to 7 kilometers. This is applicable for
areas in the southeast including Barangays Mabinit, Bonga, Matanag and
Buyoan, all in Legazpi City,
-
For other areas not covered
in item 1 above, the 7 kilometer radius Extended Danger Zone (EDZ) is now
removed. The 6 kilometer-radius Permanent Danger Zone is now in effect.
Although the alert status of Mayon has been lowered, PHIVOLCS reminds the
public that Mayon remains in an eruptive state because lava continues to
extrude from the summit crater. Such activity makes it possible for pockets
of gas-rich magma to be released explosively. There is therefore a
continuing threat of sudden explosion which could produce pyroclastic flows.
The crater rim facing the southeast is still lower than at other directions
so that any volcanic flow emanating from the crater or from lava deposits of
the upper and midslopes could threaten communities in the southeast. In
addition, lava deposits facing Barangays Mabinit and Bonga remain hot and
mobile. Thus, the margins of the lava flow deposits are susceptible to
collapse and may produce small pyroclastic avalanches which may affect areas
beyond the existing lava deposits. Residents of these Barangays are reminded
to be on full alert.
Mayon
Volcano remains at an elevated state of unrest. The new Extended Danger Zone
of 7 kilometers covering the southeast and the 6 kilometer-radius Permanent
Danger Zone for all other areas around the volcano should remain off-limits.
