It is comforting
that the Civil Aviation
Authority of the Philippines has notified pilots
to avoid the vicinity of
Mayon Volcano after
volcanologists on Monday raised to Alert Level
2 its unrest.
This means
flights are prohibited to
operate 10,000 feet from
the surface of the country’s most active of 22
volcanoes and to avoid
flying close to the volcano’s summit as ash from
the sudden phreatic
eruption can be hazardous to aircraft.
In an advisory, the Department of
Science and Technology-Phivolcs (Philippine
Institute of Volcanology
and Seismology) announced there has been
an increase in rockfall
from the 2,462-meter
tall Mayon Volcano’s
summit lava dome since
the last week of April,
from an average of five
events per day to 49
events per day from 5
am of Sunday to 5 am of
Monday.
Phivolcs advised since 10:30 pm
of June 3, visible upwelling of volcanic fluids in the Main Crater
Lake produced voluminous steam-rich plumes
that rose to 3,000 meters
above Taal Volcano Island.
The notice
should also be heeded by
to towns round the volcano and tourists, local and
foreign, intending to see
Mayon towards the end of
summer while the volcano
is in that state of “increasing unrest.”
The volcano, often described as a near
perfect cone, is geographically shared by eight
cities and towns of Legazpi, Daraga, Camalig,
Guinobatan, Ligao, Tabaco, Malilipot, and Santo
Domingo, which divide the
cone like slices of a pie
when viewing a map of
their political boundaries.
Mayon, whose
most destructive eruption
was in 1814 when it killed
1,200 people caused by
pyroclastic density currents, port eruption lahars,
and fires set alight by hot
tephra, draws tourists because of its symmetrical
cone shape.
Based on ground
deformation parameters
from electronic distance
measurement, precise
leveling, electronic tilt, and
continuous GPS (Global
Positioning System) monitoring, Mayon Volcano has
been slightly “inflated” in
ground swelling due to the
accumulation of magma
since 2020.
Under Alert
Level 2, the current unrest driven by shallow
magmatic processes
could lead to phreatic
eruptions or precede
hazardous magmatic
eruption.
The public is
advised to be vigilant
and refrain from entering the 6-km radius
permanent danger zone
to minimize risks from
sudden explosions,
rockfall and landslides.
Phivolcs said
the lava dome has increased in volume by
approximately 83,000
cubic meters since Feb.
23, and nearly 164,000
cubic meters since Aug.
20, 2022.
M e a n w h i l e ,
the highest sulfur dioxide emission was 576
metric tons last April
29, and the last measurement averaged 162
tons last May 23.
“ T h e s e
low-level volcanic
earthquakes, ground
deformation, and volcanic gas parameters
are overshadowed by
recent steep increases
in rockfall events which
may possibly lead to
further dome activity,”
Phivolcs advisory read.
