Introduction. The 11th of March 2012 is a red letter day in our Disaster Management calender. We experienced the tremors of an earthquake and were given a tsunami warning, which resulted in chaos in Colombo. Office staff vacated their seats and poured into the streets. Vehicles were at a standstill. The reason for this panic I believe is their recollection of the destruction caused by the 2004 disaster. It will be recollected that on the 26th. January 2004 we were hit by an earthquake and tsunami that caused havoc and the death of thousands. We were totally unprepared for such a disaster. This was mainly due to the fact that at that time we did not know what a tsunami was. In fact there were jokes to the effect that the Foreign Ministry on being notified that a tsunami was arriving, sent a delegation to the airport to welcome the Japanese guests!
The 2004 disaster very clearly demonstrated the destructive potential of a tsunami and an earthquake. It is therefore only logical to presume that every effort would have been made to mitigate the effects of any future such disaster. But the chaotic response of those affected by the earthquake and subsequent tsunami warning on the 11th. March 2012, indicates that we were NOT PREPARED. What is alarming is that in the last three months we have experienced three earthquakes, two in the month of May. When will we experience the next earthquake, and will we be prepared? The following three observations can be made from the above facts:
First, we appear to be in the Earthquake Zone, and therefore cannot afford to ignore the fact that there will be earthquakes in the future.
Second, the Public and Private Sector Establishments have no Earthquake Disaster Management Plans to mitigate the consequences of an earthquake.....we are not prepared. Going by previous experience in another month the three earthquakes would be history.
Third, in the event of an earthquake, the lack of an Earthquake Disaster Management Plan at office or home will cause panic, which in turn will increase the disastrous consequences of the earthquake.
DISASTER MANAGEMENT OF AN EARTHQUAKE. Earthquakes cannot be controlled but the "consequences" of an earthquake can be managed in order to mitigate the destruction that will be caused. Disaster Management of an earthquake in this context is defined as an applied science which seeks by "observation and analysis" to mitigate the consequences of such disasters. Based on this definition the loss of life and destruction of property due to an earthquake can be mitigated by a process of observation and analysis of the probable "consequences" of an earthquake. What causes the loss of life and the destruction of property are the "consequences" of an earthquake.
Therefore the most important requirement to reduce the loss of life and the destruction of property as a result of an earthquake, to a level as low as reasonably practicable, is to:
a). have a thorough understanding of the consequences of an earthquake,
b). the action required to mitigate the consequences and to,
c). formulate an Earthquake Management Plan for the office and home, based on the probable consequences
PROBABLE "CONSEQUENCES" OF AN EARTHQUAKE." The characteristic of an earthquake is the "tremor." Depending on the magnitude of the earthquake the following consequences could be expected as a result of the tremors produced by an earthquake:
Cracking and dislodging of glass.
Collapse of loose articles and furniture.
Collapse or cracks in walls.
Lifts not functioning.
External stairways not safe.
Panic and chaos.
Death and casualties.
UNDERSTANDING THE CONSEQUENCES OF AN EARTHQUAKE. Having identified the consequences of an earthquake that can cause the loss of life, injury, and destruction of property, the next step in managing the threat is to acquire a thorough understanding of the consequences in order to mitigate the consequences to a level as low as reasonably practicable, and to enable the formulation of an "Earthquake Management Plan."
Cracking and dislodging of glass. In the event of an earthquake the glass structural components of the building will be affected. Depending on the magnitude of the earthquake the glass may only crack, or may crack and fall to the floor, but will not be propelled from the frame as would happen in the event of a bomb blast. In order to eliminate or reduce the consequences of the glass dislodging and falling, the glass should be "shatter proofed." The shatter proofing of glass is expensive and should be undertaken only if there is potential danger to life, for example if there is the possibility in a high rise building of the dislodged glass falling on to the outside of the building and injuring people below.
Collapse of loose articles and furniture. In my opinion, in the current context, this is the most damaging of the consequences. Even minor tremors are adequate to cause such items as ceiling fans and filing cabinets to tilt over and fall injuring staff and obstructing emergency exit routes. A thorough survey should be made to identify all loose articles and items of furniture that can be dislodged due to the tremors caused by an earthquake, and they should be fastened to the wall to ensure that they will not collapse. As a safety measure office staff and occupants at home can seek protection during the tremor by getting under tables, beds and any other cover that will provide them protection from falling items.
Collapse or cracks in walls. The tremors of an earthquake can cause "cracks" in walls, and depending on the magnitude can even cause the walls of a building to collapse. The important factor in relation to this consequence is the "function" of the wall. If the wall is a "load bearing"component it is probable that sooner or later the building will collapse, and hence the building should be evacuated immediately. If the building collapses the debris will fall down to ground level creating a "danger zone" at the base. This danger zone at ground zero must be identified, and all evacuating staff must be instructed to stay clear of this area. The danger zone is generally a distance of one third the height of the building from the periphery of the building, for example if the building height is 30 metres the danger zone is 10 metres from the periphery at ground zero. Earthquakes cannot be controlled, and we are entering an era of high-rise buildings, hence it maybe appropriate for architects and engineers to consider including earthquake protection of buildings at the drawing board stage.
Lifts not functioning. The normal mode of vertical transport in multi-storey buildings is by lift. It has been established that in the event of an emergency people prefer to exit by the route they came in. Hence in the event of an earthquake the staff would tend to evacuate by the lifts. Depending on the magnitude of the earthquake there could be distortion of the lift well, which in turn could cause the lift to get stuck en-route and the passengers to be trapped in the lift. Therefore the decision whether the lifts should function in the event of an earthquake should be the responsibility of a senior manager.
External stairways not safe. There are two types of construction of external stairways. One is by the use of brick and mortar, which makes the external stairway a part of the entire building. The other is to "attach" a metal stairway to the outer walls of the building by means of nuts and bolts. In the event of an earthquake the nuts and bolts may get loosened causing the stairway to be weakened, and to collapse under the weight of the evacuating staff. The tremors of an earthquake may also cause the metal stairway to vibrate causing the staff using it to panic. Hence in the event of an earthquake the use of externally attached stairways may not be safe.
Panic and chaos. The characteristics of a disaster is that there is no warning, it happens suddenly, and it has the potential to cause death and destruction. Because an earthquake has the ability to cause death and destruction it induces "fear" in the human being, and since there is no warning of when the next disaster will strike the human being will panic. Panic and chaos can result in death and casualties which are not due to the consequences of the earthquake. This panic situation can be controlled by educating the human being of the consequences of an earthquake and the action that should be taken to mitigate the consequences. The action that should be taken in the event of an earthquake must be documented in an Earthquake Management Plan.
Death and casualties. The consequences of an earthquake can result in death and casualties. The deaths and casualties will depend on how well the consequences have been identified and mitigated, the staff educated in the action to be taken, the promulgation of an Earthquake Management Plan, and the implementation of the plan.
The date of the next earthquake cannot be predicted, nor can it be controlled, but by observation and analysis of the previous earthquakes we can identify the consequences and mitigate the destruction to a level as low as reasonably practicable.
~ www.island.lk ~ By Wg. Cdr. C.A.O. Dirckze
Consultant Disaster Management
Former Commandant, Civil Defence Force