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COLLEGE OF SCIENCE, TECHNOLOGY & APPLIED ARTS

OF TRINIDAD & TOBAGO

GOVERNMENT VOCATIONAL CENTRE

POINT FORTIN

DISASTER PREPAREDNESS & FIRST AID

ENV 215

LECTURER: MITRA RAMLAKHAN

ASSIGNMENT I

EARTHQUAKE DISASTER

2007.06.06

By

AKO KERN LEWIS

SELVON COARD

MARLON McSWEEN

LEON PHILLIP

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TABLE OF CONTENTS

THE MECHANISM OF AN EARTHQUAKE...…………………………….3

AGENCIES THAT CAN OFFER ASSISTANCE…………………………...4

POINT FORTIN’S VULNERABILITY TO AN EARTHQUAKE...………..7

LESSING THE IMPACT OF AN EARTHQUAKE...……………………...11

APPENDIX I....................…………………………………………………...16

REFERENCES……………………………………………………………...23

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Q State the likely mechanism of action of an Earthquake

disaster.

A An earthquake is a sudden, rapid shaking of the Earth caused by the breaking and shifting of rock

beneath the Earth's surface. For hundreds of millions of years, the forces of plate tectonics have

shaped the Earth as the huge plates that form the Earth's surface move slowly over, under, and

past each other. Sometimes the movement is gradual. At other times, the plates are locked

together, unable to release the accumulating energy. When the accumulated energy grows strong

enough, the plates break free causing the ground to shake. Most earthquakes occur at the

boundaries where the plates meet; however, some earthquakes occur in the middle of plates.

Most naturally occurring earthquakes are related to the tectonic nature of the Earth. Such

earthquakes are called tectonic earthquakes. The Earth's lithosphere is a patchwork of plates in

slow but constant motion caused by the heat in the Earth's mantle and planetary core. The heat

causes the rock under the earth to become liquid magma on geological timescales, on which the

plates are able to move, slowly but surely. Plate boundaries grind past each other, creating

frictional stress. When the frictional stress exceeds a critical value, called local strength, a

sudden failure occurs. The boundary of tectonic plates along which failure occurs is called the

fault plane. When the failure at the fault plane results in a violent displacement of the Earth's

crust, the elastic strain energy is released and seismic waves are radiated, thus causing an

earthquake.

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Q List agencies that can offer assistance to the persons

affected by Earthquake disaster.

A In the likely event of an Earthquake disaster in Point Fortin, the following agencies could offer

assistance:

WITHIN THE POINT FORTIN AREA

Point Fortin Area Hospital - provides medical attention to those who received non life-

threatening injuries.

Point Fortin Fire Station - provides fire-fighting services and search and rescue operations to

heavily affected areas.

Point Fortin Police Station – ensures public safety by controlling crowds and responding to riots

and other civil disturbances.

Point Fortin Borough Corporation – assists affected communities in evacuation procedures as

well as provides temporary shelter

Shelters for Earthquake victims

Point Fortin College

Point Fortin Junior Secondary School

Community Centres

Cap-de-Ville Community Centre

Fanny Village Community Centre

Techier Community Centre

Vance River Community Centre

Point Fortin Civic Centre George Road Mahaica

South West Regional Sporting Complex

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Petrotrin Trinmar Operations Fire Department – provide backup fire-fighting services as well as

assistance in the search and rescue operations.

Atlantic Liquefied Natural Gas Company of Trinidad & Tobago (ALNG) Fire Department –

provides backup fire-fighting services as well as assistance in the search and rescue operations.

WITHIN TRINIDAD & TOBAGO

Office of Disaster Preparedness and Management – provides information on earthquake disaster

preparedness as well as earthquake disaster mitigation and assists in formulating the Point Fortin

earthquake response plan.

Trinidad & Tobago Emergency Mutual Aid Scheme (TTEMAS) – provides mutual aid assistance

to Energy industries and areas affected by the earthquake disaster.

Emergency Health Services of Trinidad & Tobago - provide ambulance transport assistance

Trinidad & Tobago Defence Force – ensures public safety by controlling crowds and responding

to riots and other civil disturbances as well as assisting in the search and rescue operations.

Trinidad & Tobago Electricity Commission (T&TEC) – shuts off electricity supply that maybe

disrupting search and rescue operations or creating more hazards as well as restoring electricity

supply to affected areas.

Telecommunications Services of Trinidad & Tobago – restores telecommunication services to

affected areas.

Water & Sewage Authority (WASA) – provides a water supply for fire-fighting as well as

supplying a safe, palatable water supply to affected personnel.

The Seismic Research Unit, University of the West Indies – provides seismic research services to

forecast earthquake aftershocks or next earthquake disaster as well as information on earthquake

disaster mitigation.

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Ministry of Works & Transport – restores road and other vital transport infrastructure as well as

assisting in the search and rescue operations.

Ministry of Health – co-ordinates the health care relief service in the affected areas.

National Helicopter Service – provides emergency air transport services to the affected areas by

air-lifting affected and/or injured persons that cannot be reached by other means of transport as

well as air-lifting temporary relief supplies.

Ministry of Local Government – assists in formulating the Point Fortin earthquake response plan.

INTERNATIONALLY

Caribbean Disaster Emergency Response Agency (CDERA) – assists in providing information

on earthquake disaster mitigation as well as mobilizing and co-coordinating earthquake disaster

relief from governmental and non-governmental for the affected areas in Trinidad & Tobago.

Caribbean Development Agency - provides financial assistance to affected areas in Trinidad &

Tobago.

Organization of American States – assist in providing financial aid to affected areas in Trinidad

& Tobago.

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Q Explain how vulnerable the Point Fortin Region is to

an Earthquake disaster

A In Trinidad and Tobago we may feel an earthquake as often as once per month. These felt

earthquakes are only about 2-6% of the earthquakes which are recorded by sensitive instruments

called seismometers. Earthquakes occur in our region because the Eastern Caribbean forms the

eastern margin of the Caribbean Plate, which is moving eastwards at the rate of 2 cm/yr and

riding over the North and South American Plates, which are said to be subducted. The margin is

called a subduction zone. Although earthquakes occur within the earth’s rigid crust, which in our

region is about 35 km thick, the depths at which they are located in the Eastern Caribbean range

from less than 10 km to about 200 km. This is possible because the subducted plate material

maintains its rigidity as it descends and can so still allow earthquakes to be generated within the

descending slab.

Prior to 1982 most of our earthquakes were concentrated in two significant zones west of

Trinidad. One zone is north of the Paria Peninsula with events trending northeast-southwest. The

other, is in the Gulf of Paria where events have a northwest-southeast trend. In March, 1982

however, a swarm of earthquakes (several hundred tremors) occurred off the southwest coast of

Tobago. The largest of these was magnitude 5.26. Similarly, during March, 1988, the area east of

Trinidad, which up to that time had been the location of few, low magnitude events, generated a

magnitude 6.2¹º, which was followed by hundreds of aftershocks over a period of years. The

Eastern Caribbean activity along with that occurring near to Trinidad and Tobago means we will

continue to experience earthquakes of varying magnitudes.

Just off three miles of the coast of Point Fortin lies the Los Bajos Fault. This fault is 158

kilometers long and is a Dextral Strike-Slip fault. In this type of fault, the surface is usually near

vertical and the footwall moves right laterally with very small vertical motion.

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Fig 1. Schematic illustration of the Dextral (right-lateral) strike-slip fault type.

The Los Bajos fault shows a significant down-to-the-north offset on seismic profiles of

southwestern Trinidad and bounds two different seismogenic domains: an actively seismic NW-

dipping subduction slab on the northeast and a shallow crustal seismogenic province on the

southwest. It has a slip rate of roughly 5-7 mm/yr.

The Atlantic Liquefied Natural Gas Company of Trinidad & Tobago facility is divided into four

trains that are laid out over some 84 hectares of reclaimed land at Point Fortin, Trinidad. The

facility has four liquefied natural gas storage tanks; two with a storage capacity of 102,000 cubic

metres and two with a storage capacity of 160,000 cubic metres. Natural gas is supplied to the

facility through three pipelines running directly from offshore the south eastern coast of

Trinidad; British Petroleum of Trinidad & Tobago feeds gas to Train 1 through a 36-inch

pipeline, British Petroleum of Trinidad & Tobago in association with British Gas of Trinidad &

Tobago and North Coast Marine Area Partners feeds gas to Train 2 & 3 through another 24-inch

pipeline, finally Train 4 is supplied with gas through a 56-inch pipeline by British Petroleum of

Trinidad & Tobago in association with British Gas of Trinidad & Tobago and North Coast

Marine Area Partners.

While there are no known incidences of LNG storage tank failures due to seismic activity, an

earthquake could rupture the three main gas pipelines that feed the facility. Should a LNG

storage tank rupture due to an earthquake disaster, the damages could range from minimal to

catastrophic.

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LNG is a clear, non-corrosive, non-toxic, odourless, cryogenic liquid at normal atmospheric

pressure. LNG if spilled has a tendency to evaporate forming vapour clouds that could become

an asphyxiant. These vapour clouds could float into the neighbouring communities, portions of

which could become flammable or explosive under certain well-known conditions i.e. LNG has a

5-15% flammability range in air and requires an auto-ignition source (a flame or spark or a

source of heat of 1000°F (540°C) or greater) to have an instantaneous fire. If LNG is released,

direct human contact with the cryogenic liquid will freeze the point of contact. This potential

hazard is restricted within the facility boundaries and does not affect neighboring communities.

Should an earthquake disaster rupture the three main gas pipelines transporting natural gas to

Atlantic LNG, the damages could be catastrophic. Natural gas is also colourless, non-toxic and

odourless. However, as with any gaseous material besides air and oxygen, natural gas that is

vaporized from LNG can cause asphyxiation due to lack of oxygen if a concentration of gas

develops in an unventilated, confined area. Natural gas can cause flash fire (it is 100% volatile)

since it is usually stored under pressure. Natural gas is flammable and may be ignited by heat,

sparks, flames, or other sources of ignition (e.g. static electricity, pilot lights, or

mechanical/electrical equipment). Vapor clouds may travel considerable distances to a source of

ignition where they can ignite, flashback, or explode. It has an a 5.3-14% flammability range in

air and requires an auto-ignition source (a flame or spark or source of heat of 999°F (537°C) to

have an instantaneous fire.

An earthquake disaster could spell catastrophe for the Atlantic LNG facility since it built on

reclaimed land. Liquefaction is a potential hazard at this facility because of land reclamation.

Liquefaction occurs when sediments with high water content are subjected to prolonged shaking,

the pressure of the water held in pores in the sediment gradually increases eventually, the

sediments lose all cohesive strength and begin to behave as if they were liquids. Building and

other structures sink into the ground or overturn and buried tanks and other cavities rise to the

surface.

An earthquake disaster could spell catastrophe for Petrotrin Trinmar operations since it has the

majority of its operations are based offshore. The Company has 26 operational offshore oil and

gas platforms and on land it possesses 22 operational oil storage tanks. An earthquake disaster

could cause a tsunami that could devastate these oil and gas platforms. Oil and gas is the

mainstay of Trinidad & Tobago’s economy therefore a tsunami generated by earthquake

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shockwaves could gravely impact our financial well-being. Also an earthquake could rupture

Petrotrin Trinmar Operations oil and gas lines on-land causing fires, explosions and oil spills

which could have a detrimental impact on Point Fortin and surrounding areas environment.

Trinidad & Tobago Electricity Commission (T&TEC) also has an installation on the Mora Road,

Point Fortin. This installation is on a vital access route in which scores of commuters use every

day to journey from Point Fortin to Cedros and environs. Should an earthquake disaster strike

this installation, these scores of commuters are at grave risk from being electrocuted from fallen

high tension power lines and there is even a probability that they could be marooned.

Water & Sewage Authority has an installation in Hubert’s Town, Gonzales which is a short

distance from Point Fortin. This installation filters the majority of water for domestic use for

residents in Point Fortin and environs. Should an earthquake disaster strike this facility, a great

number of residents would be without safe, clean and palatable drinking water. This is a major

health risk to residents since they would seek out water that may not be fit for human

consumption, running the risk of getting tuberculosis gastroenteritis and a host of other diseases.

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Q Recommend activities and policies that may lessen the

impact of an Earthquake disaster

A Some recommendations for reducing the impact of an earthquake disaster on human life and

property can be achieved through earthquake preparedness programs which entail:

� Becoming actively involved in community preparedness organisations in your district. Call your

local disaster management office for contact information. Establishing and staffing permanent

triage zones/areas.

� Educating all family members on how to turn off electricity, gas and water using safety valves

and main switches.

� Educating family members on basic First Aid steps.

� Purchasing emergency equipment such as battery-operated radios and fire extinguishers for your

home.

� Stocking up on non-perishable food items.

� Avoiding construction in hazardous, earthquake-prone areas.

� Implementing earthquake-resistant building codes. Earthquake engineers attempt to design

buildings that can absorb excess energy without falling. Steel beams are usually the best

reinforcement because they provide the capacity to sway, stretch or vibrate, instead of breaking.

See Appendix I.

� Holding Town Meetings at regular intervals so as to inform persons residing in the area on

earthquake disaster preparedness and the roles of regional authorities and governmental & non-

governmental stakeholders play if such an event occurs.

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� Bolting bookcases, china cabinets, and other tall furniture to wall studs. Brace or anchor high or

top-heavy objects. During an earthquake, these items can fall over, causing damage or injury.

� Securing items that might fall (televisions, books, computers, etc.). Falling items can cause

damage or injury.

� Installing strong latches or bolts on cabinets. The contents of cabinets can shift during the

shaking of an earthquake. Latches will prevent cabinets from flying open and contents from

falling out.

� Moving large or heavy objects and fragile items (glass or china) to lower shelves. There will be

less damage and less chance of injury if these items are on lower shelves.

� Storing breakable items such as bottled foods, glass, and china in low, closed cabinets with

latches. Latches will help keep contents of cabinets inside.

� Storing weed killers, pesticides, and flammable products securely in closed cabinets with latches,

on bottom shelves. Chemical products will be less likely to create hazardous situations from

lower, confined locations.

� Hanging heavy items, such as pictures and mirrors, away from beds, couches, and anywhere

people sit. Earthquakes can knock things off walls, causing damage or injury.

� Bracing overhead light fixtures. During earthquakes, overhead light fixtures are the most

common items to fall, causing damage or injury.

� Strapping the water heater to wall studs. The water heater may be your best source of drinkable

water following an earthquake. Protect it from damage and leaks.

� Bolting down any gas appliances. After an earthquake, broken gas lines frequently create fire

hazards.

� Installing flexible pipe fittings to avoid gas or water leaks. Flexible fittings will be less likely to

break.

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� Repairing any deep cracks in ceilings or foundations. Get expert advice if there are signs of

structural defects. Earthquakes can turn cracks into ruptures and make smaller problems bigger.

� Checking to see if your house is bolted to its foundation. Homes bolted to their foundations are

less likely to be severely damaged during earthquakes. Homes that are not bolted have been

known to slide off their foundations, and many have been destroyed because they are

uninhabitable.

� Holding Earthquake disaster drills at least once every month.

During an earthquake the following precautions should be taken to lessen its impact on life and

property:

� Do not panic, stay calm.

� Always protect your head and face.

� If inside a building, stand in a strong doorway, or get under a desk, table or bed. Do not try to run

out of the building as you can be injured by falling debris.

� Move away from outer walls, windows, glass doors, heavy mirrors, pictures, bookcases, hanging

plants and heavy objects.

� Look out for falling plaster, bricks, lighting fixtures and other objects.

� Do not use elevators.

� If you are outside, stay there. Stand away from buildings, trees, and electricity lines.

� If you are driving, you should safely bring the vehicle to a stop away from electricity poles and

overhead wires. Remain in the vehicle.

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After an earthquake the following precautions should be taken to lessen its impact on life and

property:

� Check for injuries. Do not attempt to move seriously injured persons unless they are in

immediate danger of further injury.

� Check for fires.

� Wear shoes in all areas near debris or broken glass.

� Check utility lines and appliances for damage. If gas leaks exist, shut off the main gas valve.

Shut off electrical power if there is damage to wiring. Do not use matches or lighters until it has

been established that there are no gas leaks.

� Do not turn light switches on and off. This creates sparks that can ignite gas from broken lines.

� Clean up spilled medicines, drugs, and other potentially harmful materials immediately.

� Draw a moderate quantity of water in case service should be disrupted. Do not draw a large

quantity as this could interfere with fire fighting. If water is off, emergency water may be

obtained from hot water heaters, toilet tanks, melted ice cubes, and water packed in canned

vegetables. If water pipes are damaged, shut off water supply at main valve.

� Check to see that sewage lines are intact before permitting continued flushing of toilets.

� Do not eat or drink anything from open containers near shattered glass, as glass contamination

may exist. Only if their use is essential should liquids be strained through many folds of a clean

handkerchief or cloth.

� Check closets and storage shelf areas. Open closet and cupboard doors carefully to guard against

objects falling.

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� Check individual house or apartment building for structural damage and if deemed necessary

evacuate your family until competent authority declares it safe to return. Stay out of severely

damaged buildings; aftershocks can shake them down.

� Do not heed or spread rumours. They often do great harm following disasters. Stay off the

telephone, except to report an emergency. Turn on your radio and/or television to get the latest

emergency bulletins.

� Do not go sightseeing immediately; particularly in beach and waterfront areas, where sea waves

could strike, or in areas where buildings have collapsed or where electric wires may be down but

still alive. Keep the streets clear for passage of emergency vehicles. Be prepared for additional

earthquake shocks.

� Respond to requests for assistance from police, fire fighting, and relief organizations, but do not

go into damaged areas unless your assistance has been requested. Co-operate fully with local

authorities.

� Fill out the Earthquake Report Form and send to NEMA.

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APPENDIX I

Small Building Codes for Earthquake Considerations

3.1.7.1 Earthquake resistant construction

3.1.7.1.1 General

Trinidad and Tobago is in an earthquake zone and has experienced varying degrees of damage due to

earthquakes. It is therefore essential that buildings are designed and constructed so that they have some

resistance to the shaking or lateral forces produced by earthquakes.

3.1.7.1.2 Effect of soil type

3.1.7.1.2.1

The type of soil at the site may have a significant effect upon the resistance of the building to an

earthquake. However for buildings within the scope of this code the effect of the soil type is not so

significant provided that the building is not constructed on loose saturated sands, which may liquefy

during an earthquake and cause collapse of the building.

3.1.7.1.2.2

The earthquake may also, due to shaking of the ground, compact loose sand or fill material, and if a

building is constructed on such material, the building will be damaged.

3.1.7.1.3 Effect of high seas

Buildings on coastal areas may suffer due to high waves produced by earthquakes, and therefore the

sitting of the building in relation to the sea level needs to be considered. Professional advice shall

therefore be sought in such cases.

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3.1.7.1.4 Building shape

3.1.7.1.4.1

The success with which a building survives an earthquake is greatly affected by its shape in plan, the

way the building is tied together and the quality of construction.

3.1.7.1.4.2

Most buildings with a simple rectangular shape with no projections (or only short projections) perform

well under earthquake conditions provided the construction is adequate.

3.1.7.1.4.3

Long narrow buildings should be avoided by limiting the length to three times the width. If the building

must be longer, then it should be divided into separate blocks with adequate separation. Figure A1-1

illustrates desirable and undesirable plan shapes.

3.1.7.1.4.4

Rectangular buildings with well inter-connected cross walls are inherently strong and therefore

desirable.

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Fig A1-1 Plan of building proportion

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Fig A1-2 Recommended location of wall opening

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Fig A1-3 Recommended location of wall opening for tow storey building

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3.1.7.1.5 Appendages

Where buildings have decorative or functional additions or appendages such as window hoods, parapets

and wall panels etc. extreme care must be taken to ensure that they are securely fixed, since many of

such items tend to fall easily and may cause damage during an earthquake.

3.1.7.2 Rules for the construction of earthquake resistant buildings

It is recommended that the following rules be followed for the construction of buildings:

3.1.7.2.1 Masonry buildings

An important factor contributing to the earthquake resistance of masonry buildings is the detailing and

placing of steel reinforcement. A registered professional should undertake the design of a reinforced

concrete frame building. The reinforcing guide given in this section therefore must only be used for

simple single storey buildings constructed of approved quality masonry blocks. For the minimum

quantities of reinforcing steel to be used refer to Clause Vertical Structures.

3.1.7.2.2 Timber buildings

There are two additional areas of concern with respect to timber buildings:

All corners and intersections must be adequately braced.

Earthquake and hurricane forces tend to remove timber buildings from their supports by shaking.

Because of this sills shall be securely fastened to foundations.

3.1.7.2.3 Steel buildings

The natural ductility of steel protects the frame from severe damage. However, in many cases masonry

block walls are used and the precautions already listed for these walls will apply. The wall

reinforcement must now be anchored by welding to the steel columns and beams, or the steel frame

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encased in concrete in which case the wall reinforcement can be tied into the concrete cage encasing the

steel frame.

3.1.7.3 Location of openings

3.1.7.3.1

The location and size of openings in walls have a significant effect upon the strength of a wall and its

ability to resist earthquake forces.

3.1.7.3.2

Openings shall be located away from a corner by a clear distance of at least 1/4 of the height of the

opening. It is recommended that the minimum distance be 400 mm.

3.1.7.3.3

The total length of the openings should not exceed 1/2 the length of the wall between consecutive cross

walls (see figure A1-2).

3.1.7.3.4

The horizontal distance between two openings should not be less than 1/2 the height of the shorter

opening (see figure A1-2).

3.1.7.3.5

For two storey buildings, the vertical distance from an opening to one directly above it shall not be less

than 600mm, nor shall it be less than one half the width of the smaller opening.

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REFERENCES

www.scemd.org/Library/DisasterMitigation/Earthquake/EQBackgrounder.pdf

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

http://en.wikipedia.org/wiki/Strike-slip_fault

Map and Database of Quaternary Faults in Venezuela and its Offshore Regions by Franck A.

Audemard M., Michael N. Machette, Jonathan W. Cox, Richard L. Dart, and Kathleen M. Haller. Pg. 78

http://nema.gov.tt/resources/downloads/earthquakeriskintrinidadandtobago.pdf

http://nema.gov.tt/resources/downloads/SOP_FullDocument.pdf

www.beg.utexas.edu/energyecon/lng/documents/CEE_LNG_Safety_and_Security.pdf

http://www.uwiseismic.com/Earthquakes/eq_effects.html

http://www.boett.org/sbc/sbc03_01.htm

http://www.disastercenter.com/guide/earth.html

http://nema.gov.tt/resources/downloads/earthquakesafety.pdf

Atlantic LNG Company of Trinidad & Tobago: The Trinidad Model pgs 11 - 15