Philvolcs Alleviative Measures

8/9/2019 Philvolcs Alleviative Measures

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PHIVOLCS ALLEVIATIVE MEASURES

TO THE LIFE ENDANGERING

VOLCANIC ACTIVITIES

Abstract

Different forms of volcanic activities have different effects on people residing

near the volcano. Philippine Institute of Volcanology and Seismology (PHIVOLCS) has

taken a vital role in our society today and playing a great role in determining the status of

a volcano and on how people can prevent harm to themselves from the effects of the

volcano activities. Although, information are being announced by PHIVOLCS there are

still people who insist not to follow the warnings given by PHIVOLCS.

This thesis aims to show information on how the Philippine Institute of

Volcanology and Seismology (PHIVOLCS) acts on the different volcanic activities like Volcanic

Eruptions, Lahars, Ballistic fragments, Tephra falls, Lava flows, and Tsunamis seiches.

And how PHIVOLCS manages the safety of the people living near dormant volcanoes.


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The Problem and its Background

Volcanic eruptions are among the dreaded natural disaster in the Philippines.

Testimonies on their destructive power abound in myths, legends, and recorded history.

A volcano may either refer to a vent, hill, or mountain from which emits molten rock

and/or gaseous materials. Volcanoes are formed as a result of tectonic forces. In some

regions, the tectonic plates slide each other; in others. Plates are driven apart; and in still

others, they converge and collide. The Philippines lies in these collision or volcanic

zones.

Of the 220 volcanoes in the Philippines, 21 are considered active. A volcano is

deemed active if it has erupted within historic times. An inactive volcano may show signs

of activity after a long period of dormancy.

The Philippine Institute of Volcanology and Seismology is a Philippine national

institution dedicated to provide information on the activities of not only on volcanoes but

as well as earthquakes and tsunamis and other specialized information and services

primarily for the protection of life and property and in support of economic, productivity

and sustainable development. It is one of the service agencies of the Department of

Science and Technology. (Disasters The Philippine experience)


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Discussion

PHIVOLCS was formed to mitigate disasters that may arise from volcanic

activities. But why do such events of an eruption manage to kill and injure a great

number of people? Did they do their job properly? Do they have enough budget to buy

the latest equipment to prevent this kind of disasters that time? Did they put enough

attention to the volcanos even if it was dormant for a long time before the eruption?

These are the questions that we want answered and that is why we are conducting this

research.

Volcanic Eruptions

The most popular and well-known eruptions in the history of Philippines is the

Mount Pinatubo and the Mayon volano. Mount Pinatubo which we shall first discuss is

located on the island of Luzon in the Philippines and is part of a chain of volcanoes that

lies on the western side of Luzon in the Zambales mountain range stretching from the

Lingayen Gulf to Bataan. There are also still 22 active volcanoes in the Zambales range

and Mount Pinatubo was hidden among the other surrounding mountains. It didn't ever

get much attention because it was dormant up to 1991 and was not highly visible.

Events Leading up to the 1991 Pinatubo Eruption


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July 16, 1990: An earthquake with the magnitude of 7.8 hit Luzon with the

epicenter located approximately 55 miles northeast of Pinatubo.

March 15, 1991: A series of earthquakes occurred on the northwest side of Pinatubo and

the intensity of these earthquakes continued to increase.

April 2, 1991: Small eruptions of ash and sulfur dioxide started and the earthquakes

continued. This volcanic activity continued to increase until the end of May and then the

emission of sulfur dioxide drastically decreased. This meant the flow of magma was

blocked and a build-up of pressure would result in a large explosion.

June 3, 1991: Eruptions of magma began while ash continued to spew. These eruptions

started to increase in intensity.

June 8, 1991: An explosion-type earthquake occurred in the afternoon and this was the

beginning of intense eruptions that produced large steam clouds, heavy ash and

pyroclastic flows (hot gas and rock, also known as tephra, which quickly travels down

from volcanoes).

June 9, 1991 to June 14, 1991: Eruptions continued along with earthquakes. The ash

fallout was increased and was started to blanket surrounding towns and cities. The ash

plume which also contained pyroclastic materials had reached heights of 15 miles above

the Pinatubos vent. The flow of hot rock and other materials cascading down the slopes

blocked and overflowed rivers and streams. The strong winds blew ash throughout the

Philippines and it traveled as far as Cambodia, Vietnam and Malaysia.

June 15, 1991: Ash and volcanic materials continued to spew and two explosions in the

morning sent pyroclastic flows traveling at fast speeds of 50 mph. Further eruptions

continued and by this time, the ash plume was 30 miles high. At 10:30am, a violent

eruption occurred and it was followed by five more eruptions of equal strength. On the

same day, Typhoon Yunya hit Luzon just north of Pinatubo. This brought strong winds

that blew the ash further and the ash, when mixed with rain, made it extremely heavy.

This caused rooftops on buildings to collapse.


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June 16, 1991: Only minor eruptions occurred and seismic activity subsided.

Aftermath of the 1991 Pinatubo Eruption

There were over 700 deaths and 184 people injured and 23 people never found. Due to

well-organized evacuation efforts, fewer lives were lost. More than 1 million people were

evacuated.

The majority of deaths were caused by collapsing buildings and the death toll would have

lowered if the typhoon had not struck.

Results

Many people who lived on the slopes of Pinatubo never returned because their

land was ruined forever.

The crater on Pinatubo has filled up with water and it is now a large lake. The lava dome

formed an island within the lake.

Although, Mount Pinatubo has become a tourist attraction and visitors to Luzon

are able to take a guided tour to the crater.

Second example

Mayon Volcano is an active stratovolcano. The current cone was formed

through pyroclastic and lava flows from past eruptions. Mayon is the most active of

the active volcanos in the Philippines, having erupted over49 times in the past 400 years.


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On November30, 2006, Typhoon Durian caused mudslides of volcanic ash and

boulders from the slopes of Mayon Volcano, killing an estimated 1,000 and covering a

large portion of the village of Padang (an outer suburb of Legazpi City) in mud up to the

houses' roofs.

Results

The number of dead was at least 1,266 people, about half the death toll of the 1814

eruption. The precise figure may never be known since many people were buried under

the lahars, and entire villages disappeared.


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Review of related literature

Mayon volcano in minor eruption, spews ash

by Katherine Evangelista (12/16/2009)

INQUIRER.net

According to Alanis, although the Mayon volcano is dormat it is very much

active when properly measured

Mayon Volcano experienced a minor eruption Wednesday,

spewing ash reaching up to 500 meters, the Philippine

Institute of Volcanology and Seismology (Phivolcs) said.In a

telephone interview, Phivolcs Science Research SpecialistPaul Alanis said that the minor eruption was recorded at

around 10:16 a.m.At least 78 volcanic earthquakes were also

recorded in the last 24 hours, Alanis said.Volcanic

earthquakes are normal with the Mayon Volcano even when

there is no alert level raised but only five minor quakes are

recorded on the average,

Alanis said."Ibig sabihin, talagang active ang bulkan ngayon

[This means that the volcano is really active]," Alanis

said.Alert level 3 remains over Albay province, but Phivolcs

may raise it to alert level 5 depending on volcanic activities

like increased siesmic activity, increased emissions of sulfur

dioxide, swelling of the volcano and other physical

manifestations indicating a bigger eruption, Alanis said.


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In other words immediate evacuation is necessary no matter what minor

indications maybe of an eruption, take this other article for example for evacuations.

Mount Pinatubo, Evacuation,

From Wikipedia, the free encyclopedia

(http://en.wikipedia.org/wiki/Mount_Pinatubo)

Given all the signs that a very large eruption was imminent,

PHIVOLCS assisted by the US Geological Survey, worked to

convince people in the local area of the severity of the threat. A

false warning might have led to cynicism about any later

warnings but delaying a warning until an eruption began might

lead to thousands of deaths, so the volcanologists were under

some pressure to deliver a timely and accurate assessment of the

volcanic risk.

Three successive evacuation zones were defined, the innermost

containing everything within 10 km of the volcano's summit,

the second extending from 10 to 20 km from the summit, and

the third extending from 20 to 40 km from the summit (Clark

AirBase and Angeles Citywere in this zone). The 10 km and

1020 km zones had a total population of about 40,000, while

some 331,000 people lived in the 2040 km zone. Five stages of

volcanic alert were defined, from level 1 (low level seismic

disturbances) up to level 5 (major eruption in progress). Daily

alerts were issued stating the alert level and associated danger

area, and the information was announced in major national and

local newspapers, radio and television stations, nongovernmenta

l organizations (NGOs), and directly to the endangered

inhabitants.

It is recorded in this article that quick action and predictions of PHIVOLCS and

by the US Geological survey proved to be accurate. The evacuation in the days


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preceding the eruption certainly saved tens of thousands of lives. So PHILVOCS

managed its duties to save many lives as possible, although many have still have died

due to an unforeseen phenomenons accompanying the eruption.

Discussion and Analysis

As previously discussed, not only is an eruption dangerous but as well as the

aftermath effects that are called volcanic phenomenas that are equally devastative.

Take this table for example;

Table. Volcanic Phenomena , Attendance Dangers and Alleviative Measures

SOURCE: DISASTERS AND DEV. BY FREDERICK CURY, 1983

VOLCANIC

PHENOMENA

ATTENDANT

DANGERS/ EFFECTS

PROTECTIVE/

ALLEVIATIVEMEASURES

Ballistic fragments

Tephra falls

Lava flows

Lahars

Landslide

Tsunamis seiches

Bomb impact, Inceneration

Roof collapse, ash asphyxiation, burial,

effects on eyes and respiratory system

Burial, bulldozing, building collapse,mudflows, floods, explosions in water,

fires

Burial of living things, town, andagricultural lands, burning, drowning,

crush injuries, abrasion, impact effects

Burial, abrasion, destruction ofbuildings, infrastructures & agricultural

lands

Drowning, flooding, excessive lateral

force, transport, foundation failure

Restrict from area, use headpadding, take shelter

Use personal covering/facemasks, restrict activity.

Scrape roofs, trees, cleardrains, restrict grazing

animals.Divert by bombing, artificial

channelways or dams, coolwith water

Drian crater lakes, construct

dams, evacuation hills andlahar pockets, revegate and

employ other soilconservation methods.

Issue warning, use landslide

mitigation and controlmethods

Adapt effective warning

system, evacuation, land usezoning, and appropriate

building specs


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As shown is the table complete and thorough safety measures must be observed

and implemented to avoid incoming disasters, So the best thing to work on towards

incase of an eruption is to be prepared of unexpected changes and be one step ahead from

impending danger which would threatened our lives. Evacuate the dangerous areas

affected by the volcanic activity and follow suggested alleviative measures.


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Appendix A

Pinatubo early eruption 1991

One of the early explosive eruptions at Pinatubo after the April 1991 onset of ash

eruptions


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Appendix B

School buried by lahar; photograph taken on October 12, 1991

Rain-triggered lahars at Mount Pinatubo, Philippines

Like thousands of other buildings downstream from Mount Pinatubo, this school house

was buried by a lahar after the enormous eruption on June 15, 1991.


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Appendix C

Tiltmeter (a.k.a. Tilt pot)

A tiltmeter is an instrument designed to measure very small changes from the horizontal

level, either on the ground or in structures. A similar term, in less common usage, is

the inclinometer. Tiltmeters are used extensively for monitoring volcanos, the response

of dams to filling, the small movements of potential landslides, the orientation and

volume of hydraulic fractures, and the response of structures to various influences such

as loading and foundation settlement.


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Bibliography

School buried by lahar; photograph taken on October 12, 1991

Retrieved from:http://images.google.com.ph/imgres?imgurl=http://volcanoes.usgs.gov/Imgs/Jpg/

Pinatubo/30410914_060_large.jpg&imgrefurl=http://volcanoes.usgs.gov/hazards/lahar/rain.php

Pinatubo early eruption 1991

Retrieved from:

http://en.wikipedia.org/wiki/File:Pinatubo_early_eruption_1991.jpg

Mount Pinatubo, Evacuation.

Retrived from:(http://en.wikipedia.org/wiki/Mount_Pinatubo)

Mayon volcano in minor eruption, spews ash

by Katherine Evangelista (12/16/2009)

Retrieved from: INQUIRER.net

Tiltmeter (a.k.a. Tilt pot)

Retrieved from:

http://en.wikipedia.org/wiki/Tiltmeter


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