The impact of volcanoes, earthquakes
Marjorie Henry, Contributor

The last lesson ended with a discussion on the impact of natural hazards on Caribbean territories. This was section (b) (ii) of Question 8 on the June 2007 CSEC question paper. Three such hazards were given in the question, namely, hurricanes, volcanoes and earthquakes. The impact of hurricanes was discussed in the last lesson. I will now go on to the others.

Volcanoes

• Pyroclastic flows destroy everything in its path as it rushes forward. Pyroclastic flows will also ignite fires.
• Poisonous gases are given off and therefore threaten life as they cause suffocation. These gases are also corrosive.
• Ash falls, if heavy, are destructive. The ash can bury buildings and roads, destroy crops and be a general health hazard.
• Mudflows, or lahar, bury everything in its path.
• New lands are created from volcanic materials.

Earthquakes

• The damage resulting from earthquakes varies with intensity and nearness to the epicentre.
• The tremors may crack walls and break windows. Some buildings could collapse under the strain, burying the people inside them. Utility poles may fall, leaving live wires exposed.
• Ground fissures may be formed when there is a powerful earthquake. These can break pipelines, roads and bridges and cause fires in the process.
• Reclaimed land or loose sediments which are saturated with water may behave like a liquid during an earthquake. This is referred to as liquefaction. Buildings may sink into the ground or overturn.
• Tsunamis caused by underwater earthquakes can sweep away coastal settlements.

Here is section (c) of Question 8. It also has two sub-sections:

i) For the hazard chosen in (b) (ii) suggest TWO precautionary measures that individuals can take to reduce the impact.

Precautionary measures that individuals can take to reduce the impact of hurricanes include the following:

• Board up windows or put storm shutters in place. These will protect the glass.
• Have strong embracing for outward door.
• Reinforce roof so that it can withstand the force of the winds.
• Secure loose objects.
• Remove branches from nearby trees which may fall on houses or electricity poles.
• Water heaters should be taken down from the roof.
• All persons should evacuate from coastal areas or beaches which may be swept by high tides or storm waves. Evacuate to a recommended place of refuge.
• Be aware of emergency numbers.
• Stock up on food, water and other necessities.
• Have a fire extinguisher on hand.

Precautionary measures that individuals can take to reduce the impact of volcanoes include the following:

• Be alert. Listen for warning to evacuate the area which is a danger zone.
• In the safe zone, close all windows and doors. Stay inside during the eruption.
• Avoid low-lying areas where poisonous gases can accumulate.
• Avoid the areas that are downwind of the volcano.

Precautionary measures that individuals can take to reduce the impact of earthquakes include the following:

• Observe building codes. Buildings in earthquake-prone areas are being designed and constructed to resist earthquake shaking.
• All buildings must be maintained. Doors, windows and roofs must be in good condition.
• High-occupancy buildings or critical structures should not be placed or built near faults or on landslide prone areas.
• Strap water heaters to the wall with steel bands.
• Fasten heavy objects to the wall or place them on lower shelves. Bolt cupboards to the wall.
• Turn off electricity, gas and water mains.
• Homes and private businesses should have proper insurance.

The second sub-section of (c) requires that you explain measures that have been adopted by the government to reduce the impact of these hazards. Reflect on these for the next lesson.

St Hugh's girls Karis Passley (foreground), Kristina Hepple (left), Tameka Thorpe (centre) and Dahlia Jones pose for the camera during the fourth and final day of the Inter-secondary Schools' Sports Association GraceKennedy Boys' and Girls Athletic Championships at the National Stadium on March 15. - Anthony Minott/Freelance Photographer

Marjorie Henry is an independent contributor.