EARTHQUAKES: Beyond the shaking
WHEN THE EARTH DECIDES to give a little hiccup and we all feel the tremor, it’s important to remember that the worst could be yet to come. Even with small quakes, the after-effects can bring the real devastation. More than just aftershocks, which are like ripples in a pond, landslides, fires, soil liquefaction, tsunamis, floods, and even disease may follow.
As far as science has come, there are still huge blocks in our understanding of the world. Earthquakes and volcanic activity go hand in hand but don’t always come together. Quakes can cause volcanic activity and vice versa.
In 1835, during his voyage on the HMS Beagle, Charles Darwin experienced a large earthquake that occurred near Concepción, Chile. He wrote, “at the same hour when the whole country around Concepcion was permanently elevated, a train of volcanoes situated in the Andes, in front of Chiloe, instantaneously spouted out a dark column of smoke […] We thus see a permanent elevation of the land, renewed activity through habitual vents, and a submarine outburst, forming parts of one great phenomenon”.
Landslides are an obvious effect. When the earth trembles in areas of unstable soil, gravity can then cause the toppling of loosened mass quantities of earth to move downhill. The landslides are often not just topsoil but boulders, trees, and anything shaken free in the upheaval which can come tumbling down as a result. It’s important to stay away from areas where this could pose a threat.
Soil liquefaction can cause sinkholes to open up, the threat of that occurrence is pretty obvious. If a tsunami warning is issued, it’s important to have a plan to reach higher ground. The devastation of the Indian Ocean tsunami speaks for that potential horror and the subsequent flooding can lead to stagnation of water and the creation of disease.
Like with the massive San Francisco quake of 1906, intense and widespread fires can cause more damage and loss of life than the initial tremor. Today, most streets are lined with electrical wires that keep us connected to the grid for electricity and communication. If those lines are compromised, loss of communication and power are the least of worries as electrical fires become a significant threat.
If fires break out after a quake, they could be from different causes. Gas mains can fracture and leak. It’s important to know the cause of a fire and the fuel it is burning before attempting to extinguish it.
•Class A: Solids such as paper, wood, plastic, et cetera.
•Class B: Flammable liquids such as paraffin, petrol, oil, et cetera.
•Class C: Flammable gases such as propane, butane, methane.
•Class D: Metals such as aluminium, magnesium, titanium, et cetera.
•Class E: Fires involving electrical apparatus.
•Class F: Cooking oil and fat, et cetera.
Water fire extinguishers
The cheapest and most widely used fire extinguishers. Used for Class A fires. Not suitable for Class B (liquid) fires or where electricity is involved.
Foam fire extinguishers
More expensive than water, but more versatile. Used for Class A and Class B fires. Foam spray extinguishers are not recommended for fires involving electricity, but are safer than water if inadvertently sprayed onto live electrical apparatus.
Dry powder fire extinguishers
Often termed the multipurpose extinguisher, as it can be used on Class A, Class B and Class C fires. Best for running liquid fires (Class B). Will efficiently extinguish Class C gas fires, But beware, it can be dangerous to extinguish a gas fire without first isolating the gas supply. Special powders are available for Class D metal fires.
Warning: When used indoors, powder can obscure vision or damage goods and machinery. It is also very messy.
Carbon dioxide fire extinguishers
Carbon Dioxide is ideal for fires involving electrical apparatus, and will also extinguish Class B liquid fires, but has no post fire security and the fire could reignite.
Specialist extinguisher for Class F fires.
For metal fires: A specialist fire extinguisher for use on Class D fires – metal fires such as sodium, lithium, manganese, and aluminium when in the form of swarf (chips) or turnings.