Transcript Preparing for Volcanoes

Hazards: Take Control
Volcanoes
By NEMO Saint Lucia
DISASTER RISKS FACED BY THE CARIBBEAN
Source: Primer Series by the Global Alliance for Disaster Reduction
EARTHQUAKES
FIRES
GOAL: REDUCE DISASTER
RISK
DEVELOP POLICIES FOR
ACTIONS HAVING HIGH
BENEFIT/COST FOR THE
CARIBBEAN REGION
HURRICANES
VOLCANOES
FLOODS
LANDSLIDES
MEDICAL EMERGENCIES
ENVIRONMENTAL IMPACTS
GLOBAL CLIMATE CHANGE
Hazard: Volcanoes
The term VOLCANO signifies a
mountain or hill with an opening or
vent from which gaseous liquid or
solid materials from the earth's
interior are ejected. The term is also
used for mountains, hills, or craters
formed by the accumulation or
removal of materials during past
volcanic events even if no active
vent is presently existing.
Caldera -- a cauldronlike volcanic feature
usually formed by
the collapse of land
following a volcanic
eruption. They are
sometimes confused
with volcanic
craters. The word
comes from Spanish
caldera, and this
from Latin
CALDARIA,
meaning "cooking
pot".
http://en.wikipedia.org/wiki/Caldera
http://www.escholarship.org/editions/view?docId=ft6v19p151&doc.view=con
tent&chunk.id=d0e11795&toc.depth=100&anchor.id=0&brand=eschol
Hazard: Volcanoes
Hazard Defined
Qualibou Caldera in Saint Lucia [aka Sulpher Springs]
http://www.ict.oxon-lea.gov.uk/st_lucia_project/jlphotos/Sulphur%20Springs1.jpg
Hazard Defined
Hazard Defined
BLASTED PROJECTILES: Large projectiles can
damage buildings; if these are hot they can start
fires.
LAVA FLOWS: These are flows of extremely hot
molten rocks extruded by the volcano. The
viscosity and high temperature make these flows
very dangerous and they are capable of
destroying all in their path.
Hazard Defined
MUD FLOWS (lahars): a dense mixture of rock
debris and water originating from a volcano.
The source of the water may be a crater lake,
heavy rain or snow. The loose ash and volcanic
fragments are transformed into a dense fluidrock mixture that rushes down the slopes of the
volcano and into surrounding valleys.
Hazard Defined
GASES: …are released into the atmosphere from
volcananic vents, degassing of soils, fumaroles and
hydrothermal systems. The gases are composed
mainly of water vapour, carbon dioxide and sulphur
dioxide. They are often acidic and can be harmful
even at low concentrations.
Hazard Defined
PYROCLASTIC FLOWS: Mixtures of hot gases,
ash, fine pumice and rocks; danger lies in the
density and temperature of the ash and rock
fragments. Pyroclastic flows can move at very
high speeds, possibly over 100 km/h. Hazards
include body surface burns, inhalation injuries
and asphyxia.
Hazard Defined
LOCAL EARTHQUAKES: Possible loss of human
life and property.
TSUNAMIS: Tsunami is Japanese for “giant wave",
the seismic wave that can hurtle across oceans at up
to 600 miles per hour (800 km/hour). Occurrence is
unpredictable and can destroy coastlines.
Carbon Dioxide
The problem is complex, for volcanoes can help cool the earth's surface by
forming sulfuric acid aerosols that reflect the sun's rays, and also contribute to
global warming by giving off carbon dioxide into the atmosphere, which
contributes to the greenhouse effect. Greenhouses (or, hot houses) are heated by
the sun's rays that enter through glass or plastic, and the heat is retained inside like
a parked car on a hot day with the windows rolled up. Carbon dioxide behaves
like a glass shield over the earth. The sun's rays penetrate the carbon dioxide gas
but the carbon dioxide shield prevents heat from escaping into the atmosphere.
Sulfur Dioxide
The greatest volcanic impact upon the earth's short term weather patterns is caused
by sulfur dioxide gas. In the cold lower atmosphere, it is converted to sulfuric acid
by the sun's rays reacting with stratospheric water vapor to form sulfuric acid
aerosol layers. The aerosol remains in suspension long after solid ash particles have
fallen to earth and forms a layer of sulfuric acid droplets between 15 to 25
kilometers up. Fine ash particles from an eruption column fall out too quickly to
significantly cool the atmosphere over an extended period of time, no matter how
large the eruption.
SOURE: http://volcanology.geol.ucsb.edu/gas.htm
Hazard Defined
Chlorine
Chlorine gas can negatively effect the earth's environment. Chlorine is emitted
from volcanoes in the form of hydrochloric acid (HCl), which breaks down into
chlorine and chlorine monoxide (ClO) molecules. The sulfate aerosols furnish
sites for chemical reactions that release the chlorine atoms. These eruption-derived
chlorine atoms are added to man-produced chlorine already present in the
stratosphere. The reactive chlorine atoms then proceed to destroy ozone, with each
chlorine atom being recycled many times.
Fluorine
Fluorine gas can condense in rain or on ash particles and coats grass and pollutes
streams and lakes with excess fluorine. Animals that eat grass coated with fluorinetainted ash are poisoned. Small amounts of fluorine can be beneficial, but excess
fluorine causes fluorisis, an affliction that eventually kills animals by destroying
their bones.
SOURE: http://volcanology.geol.ucsb.edu/gas.htm
Hazard Defined
Preparing for Volcanoes
THE KEY IS:
1) KNOW THE DISASTER
HISTORY OF YOUR
REGION
2) KNOW YOUR
COMMUNITY
Preparing for Volcanoes
• Discuss the hazard with your
family.
• Prepare a disaster plan.
• Know the safe zones.
• Prepare an evacuation plan.
• Don’t forget your pets!
Preparing for Volcanoes
Very often it will be years, decades even
generations before it will be safe to
return to a community that has been
affected by an eruption.
Take as much as you can.
Don’t forget your livestock!
Preparing for Volcanoes
Alert Level
GREEN
Symptoms
Action by scientists (SRU)
Volcano is quiescent,
seismic and fumarolic
(steam vent) activity
are at or below the
historical level at this
Normal monitoring
volcano. No other
unusual activity has
been observed.
Preparing for Volcanoes
Alert Level
YELLOW
Symptoms
Action by scientists (SRU)
Volcano is restless;
seismicity or
fumarolic activity or
both are above the
Monitoring system will be
historical level at this
brought up to full
volcano or other
capability. Civil
unusual activity has
authorities alerted.
been observed (this
Communication system
activity will be
tested.
specified at the time
that the alert level is
raised).
Preparing for Volcanoes
Alert Level
ORANGE
Symptoms
Action by scientists (SRU)
Monitoring system
continuously manned.
Regular visual inspection of
potential vent areas.
Highly elevated level of
Continuous ground
seismicity or fumarolic
deformation and
activity or both, or
hydrothermal monitoring.
other highly unusual
Daily assessment reports to
symptoms. Eruption
civil authorities. Entry to the
may occur with less
restricted-access zone will be
than 24 hours-notice.
permitted to scientists after
an evaluation on a case-tocase basis.
Preparing for Volcanoes
Alert Level
RED
Symptoms
Action by scientists (SRU)
Eruption is in
progress or may
occur without further
warning.
Measurements as
permitted by safety
conditions. Civil
authorities advised
continuously.
Preparing for Name
“It is generally accepted that disaster
mitigation pays. For example, the
World Bank and United States
Geological Survey once calculated
that economic losses worldwide
from natural disasters during the
1990s could be reduced by $280
billion if $30 billion were invested
in disaster mitigation and
preparedness — a ratio of $7
saved for every $1 spent.”
Twigg 2001, p. 3.
Preparing for Volcanoes
I want to urge you to act now in getting the insured
household percentage up from 35%. I want to
challenge you to strive at a 60% figure for this
year, no matter how painful the financial cost
Dr. Kenny D. Anthony
Prime Minister of Saint Lucia
January 16, 2005
Early Warning Systems
The four components of an early
warning system:
1. Monitor the hazard;
2. Quantify the hazard;
3. A disaster plan to address the
hazard; [Volcanic Eruption Response Plan,
Community Evacuation Plan, Family Disaster
Plan]
4. Effective communications for
warning.
Effects of Volcanoes
The most common cause of death from a volcano is
suffocation. There is also the risk of:
injuries from falls
drinking water contamination
infectious disease
burns
respiratory illness
vehicle accidents related to the slippery, hazy
conditions caused by ash
ALL CLEAR
Very often it will be years, decades even
generations before it will be safe to
return to a community that has been
affected by an eruption.
Online Resources
National Emergency
Management Plan
http://stlucia.gov.lc/nemp
Family Disaster Plan
http://www.cdera.org/doccentre/familyplan.html
Family Evacuation Plan
http://stlucia.gov.lc/nemp/plans/EvacTemplate.doc
Family Disaster Supplies List
http://www.stlucia.gov.lc/docs/nemo/FamilyDisasterSup
pliesCalendar.pdf