PHIVOLCS EARTHQUAKE DIASTER MITIGATION PROGRAM
SEISMIC MONITORING
PHIVOLCS is the government agency mandated to monitor
earthquake occurrences in the Philippines. One of its programs is
geared towards increasing people’s understanding of the causes,
effects, nature and physics of earthquakes and related events
such as tsunamis, landslides and faulting. Among the continuing
and projected activities are studies on earthquake source
mechanisms, strong ground motions, delineation of seismic zones
and earthquake prediction techniques. This program generates
information needed for earthquake disaster preparedness
planning, vulnerability or risk studies, earthquake disaster
mitigation studies, and information campaigns.
• The key to effective disaster prevention is planning.
Determine whether your chosen site for development is
traversed by a ground fracture or fault. Observe proper
easement from fault trace.
• Note the presence of other potential sources of hazards
due to secondary effects of earthquakes like hillslopes
or facing open seas.
• Adhere to sound building and construction practices.
SEISMIC HAZARDS IDENTIFICATION
& MAPPING
Seismic hazards identification, active fault mapping, and tsunami
hazards assessment and mitigation are among the ongoing R&D
projects of PHIVOLCS in order to delineate earthquake hazard
prone areas in the country.
GEOLOGIC DISASTER MITIGATION MEASURES
FOR VOLCANIC DISASTERS
PHIVOLCS Data Receiving Center
The first step towards safeguarding life, properties and
investments from volcanic hazards is to understand how and why
they occur and know what areas are likely to be affected by these.
• Comply strictly with PHIVOLCS’ prohibition against
human settlement in permanent danger zones. Always
be on alert and listen to advisories of not venturing into
identified restricted areas during volcanic unrest.
• Identify, evaluate and characterize areas vulnerable to
hazards and implement appropriate land use plan and
zonation.
• Heed warnings and evacuation orders in times of
volcanic unrest.
FOR EARTHQUAKE DISASTERS
The occurrences of earthquakes cannot be prevented. Although
some work is currently being done to understand earthquakes in
more detail, no earthquake prediction can yet be issued with
confidence. Therefore, the only way to prevent disasters is to
anticipate and prepare for them.
Satellite dish installed at PHIVOLCS Central Office.
Seismic data from remote stations will be relayed to
PHIVOLCS
Central
Office
through
satellite
communications
PHILIPPINE INSTITUTE OF VOLCANOLOGY
AND SEISMOLOGY
Department of Science and Technology
PHIVOLCS, July 2003
WHAT ARE GEOLOGIC HAZARDS?
PHIVOLCS VOLCANIC DISASTER MITIGATION
PROGRAM
Geologic hazards are normal and their earth processes occurring
as irregular events which direct interaction with the environment is
capable of causing significant negative impact on man’s well
being. Their non-rhytmic occurrence makes their predictability
difficult. An important characteristic of many geologic hazards is
their prime land preference – the characteristic of preferentially
occupying areas targeted by man for his use.
Almost all types of geologic hazards occur in the Philippines
except hazards associated with glaciers and seasonal snowfall.
Hazards arising from volcanic eruptions, earthquakes and other
related geotectonic phenomena such as landslide, tsunami and
faulting are the most mitigated ones due to the recently of their
occurrence.
VOLCANIC HAZARDS
•
•
•
•
LAVA FLOWS – hot, incandescent molten rocks that
are erupted quietly and cause permanent damage to
areas they cross over by burial and extreme heat
PYROCLASTIC FLOWS – ground hugging turbulent,
hot masses of fragmented volcanic rocks and ashes
that move rapidly down slope. It is considered the most
dangerous because they burn and bury anything they
cross.
TEPHRA FALL – (ASH FALL) showers of fine-tocoarse grained volcanic materials and other airborne
products of volcanic eruptions.
LAHARS – mixture of water, mud, and rock, forming a
slurry like that of a cement. Lahars destroy properties
around the volcano by burial of large areas under thick
volcanic debris.
Glowing lava flowing down the slopes of Mt. Tabaro
Eruption Site during the 1969 Taal Volcano eruption.
VOLCANO MONITORING & ERUPTION PREDICTION
One of the principal mandates of PHIVOLCS is to avert or
mitigate disasters that may arise from volcanic eruptions. In order
to accomplish this task, PHIVOLCS perform the following:
Bacolor Town in Pampanga buried by Pinatubo Volcano
lahar deposits.
EARTHQUAKE HAZARDS
• GROUND SHAKING - the disrupting up-down and
sideways motion experienced during the event.
a. LIQUEFACTION – is a process by which loose
saturated sand lose strength during an earthquake
and behave in a similar fashion to a liquid.
b. LANDSLIDE – downward movement of slope
materials either slowly or quickly in steep or hilly
areas.
• GROUND RUPTURE – deformation on the ground that
marks the intersection of the fault plane with the earth’s
surface.
• TSUNAMIS – giant sea waves generated by under-sea
earthquake.
Ground rupture of the 16 July 1990 Luzon Earthquake
Maharlika Highway, Caranglan. Nueva Ecija
• Predict the occurrence of volcanic eruptions and
determine how eruptions shall occur and also areas
likely to be affected.
• Formulate appropriate disaster-preparedness plans and
mitigate hazards of volcanic activities through
appropriate detection, forecast and warning system;
and
• Exploit positive aspects of volcanoes and volcanic terrains
in furtherance of the socio-economic development
efforts of the government.
HAZARDS IDENTIFICATION & MAPPING
PHIVOLCS primary objective is to conduct R&D to identify
hazards in volcanic areas with the ultimate goal of generating
hazards maps for active and potentially active volcanoes.