When in a structure during an earthquake, you are in danger mostly from four main areas:
- Injury from glass shards.
- Injury or entrapment due to structural collapse.
- Injury from falling fixtures and fittings.
- Injury or entrapment due to fire or explosion.
To help you decide on any actions available to you, a general risk assessment must be carried out, which will try and identify the most serious risk.
Once you have identified the risk(s) that you consider the most likely to affect you, it is then possible to plan your actions.
Please note that this process must be carried out for each building or even room you will occupy. Such a detailed assessment may not be possible/practical, in which case, you must use a common sense approach.
When you move into an area, try and find out locally what the risks are: (Italics gives general ideas on what to look for and what its effects may be.)
Is the risk of a major earthquake high?
Information may be available from the Embassy, local authorities, and local population or on Internet. If risk is low, perhaps it is best to look at your place of residence only and not end up paranoid. If the risk is high, develop your assessment skill, into a daily routine as you move from building to building.
What is the building standard, (earthquake proof, normally suffer collapse during events, unknown)?
If earthquake resistant construction, look at internal hazards from fixtures and fittings. If the standard is low, consider if evacuation is best? Remember that in a large event, your ability to run, or even walk, may quickly be reduced to nil.
What are the buildings made from? Concrete, brick, stone etc.
In general concrete slabs produce the best chance of voids (spaces) during a collapse; bricks, blocks and stone crumble leaving only small, if any voids.
How high is the building and how far to open air?
This will simply affect the time taken if you decide to evacuate. Height will not affect the safety of the building; this is mostly governed by material, design and quality of construction.
How much glass has the building, both internal and external?
Glass is considered as one of the largest risks of injury, both inside and outside structures.
How close are other structures?
Evacuation from one structure may put you in danger from nearby risks.
What type of fixtures and fittings are in place?
All fixtures and fittings are potential hazards during an earthquake. They will move, topple, crush down or endanger you in other ways.
They can, however, also provide protection from glass and even collapse.
When will you be in the building, (working, sleeping etc)?
This indicates the time scale during which you will be at risk and also your possible physical and mental state should an event happen.
How large are the rooms inside the building?
A simple rule of thumb is that small rooms tend to survive better than larger rooms. This is a general rule, which is affected by materials and type of construction.
Does the building or locality have a gas supply? If yes, is it bottled or from a main?
Bottled gas tends to be in small quantities, although the hazard from the cylinder must be considered, especially if a fire starts. Gas from ruptured mains can leak for long periods, feeding the risk from fire, explosion or asphyxiation.
Based on your information from the above assessment, you must make a decision as follows:
- Can you very quickly and safely exit the building?
- If you exit the building will you be safe from glass shards?
- If you exit the building will you be safe from falling debris, either from your own or other structures?
- Can you protect yourself from glass shards if you remain in the building? This can be under tables, desks, moving into a room without windows, behind a fixture, etc.
- Can you protect yourself from falling fixtures and fittings if you remain in the building?
- Is there any large, substantial furniture within the building?
- Can you quickly access a small room?
If you can definitely answer YES to questions 1, 2 and 3 above, then probably your best action is to try and exit the building.
It would be hoped, that most modern buildings would have a degree of safety built into their design and construction. This may indicate that the greatest danger is from glass, fixtures and fittings. If this is assessed as the main danger, to reduce this, protect yourself by getting under a substantial table, desk, or by moving into a room with few or no windows. Remember that the object you choose as your protection may move and if you have retired to a small windowless room, there is little space for any falling objects. At least try to get away from windows and overhead fixtures or fittings, possibly under a door lintel, which may give a degree of safety, with the doorframe also providing some protection from moving objects.
If the danger is from building collapse, then sheltering under a table or desk is not the best option. The legs will probably flatten and you could be compressed under it. If it is substantial, it possibly will not flatten completely, leaving a safe area beside it. Such an object, will often support a concrete slab, creating a void, (space), in which rescue teams can locate persons many days after the event. If you lie beside this object, you may be safe within such a void. Lying on the side furthest away from the windows, will also give some protection from glass shards.