As the recent tragedy in New Zealand has once again demonstrated, earthquakes represent a continued danger to public safety across the world, regardless of whether they occur in developed or emerging economies.
They present governments and relief organisations with a unique set of challenges for coordinating an emergency response both during and after the event. Perhaps the most intractable challenge lies in how to re-establish a communications platform to the public affected by the earthquake.
Governments are primarily concerned with how to warn populations in at-risk areas that an earthquake may be imminent so that they can take appropriate steps. Seismologists are still some way off from being able to accurately predict earthquakes in the long/midterm, but early warning devices can give a vital few seconds advanced warning.
The issue is how to transmit that warning to all citizens in the disaster zone so that they can find shelter before the tremors actually start. Television, radio and sirens have all been used in the past, but they have their limitations. TV and radio will only alert people who are actively listening to a broadcast – during working hours that is a very small proportion of the total public. A siren alert, on the other hand, is a ‘dumb’ system: it tells people that something is happening, but not what – and crucially not what the appropriate action should be. A system is needed that can immediately tell all people within a given geography that an earthquake is imminent and that they should take shelter either outdoors or under a table or doorframe for example, immediately.
The mobile phone represents the best channel for relaying this information. Even in developing countries mobile phones are the most ubiquitous communications channel and subscription levels continue to grow exponentially. In addition, as mobile phones can support text messages, they have the ability to convey the level of detail needed during earthquake alerts. Getting the necessary information to mobile phones, however, is not as simple an issue as it first seems.
SMS text messaging is the most widely used messaging system, but it is limited as a medium for public warning. As a point-to-point technology, SMS requires that an individual message is sent to each device. This slows the messaging process and in the case of an earthquake early warning system this time delay would render the system impractical. SMS is also limited for public warning as it relies on users registering phone numbers with the authorities. There are privacy concerns here, as the only way a government would be able to send text messages to all users within a specific location would be to track their movements. This is too ‘big brother’ to work in practice.
There is however a messaging service far more practical for public warning. To the end user, Cell Broadcast resembles SMS very closely. The technology works on a one-to-many basis, meaning that one message can be sent to many hundreds of thousands of devices, instantly. These messages are sent to all phones within reach of specific mobile telephone masts, making it a location-specific solution and one without the need to register or track devices. As an early warning alert comes in for an earthquake in a specific geographic location operatives can send a message to everyone within that area instantly, whether locals or visitors, giving them the appropriate level of information to take action immediately.
In the aftermath of an earthquake, Cell Broadcast can continue to offer governments and public safety agencies a useful communications channel. As the recent Haiti earthquake showed, telephone networks often survive earthquakes, but due to the huge amounts of traffic going over the voice and data channels they often fall over and cannot support voice and text messages. Cell Broadcast however has its own dedicated broadcast channel and would continue to function, allowing relief agencies to convey essential information to the public such as where food and medical relief can be found and whether they need to take shelter in advance of aftershocks.
Cell Broadcast is already garnering much interest from governments across the world for public warning services including EU-Alert (Europe) and CMAS (US) as well as the Earthquake Tsunami Warning System (Japan). The Dutch Ministry of the Interior is currently rolling out a public warning system based on Cell Broadcast technology following a very successful trial in Zeeland. The results of the trial were impressive, showing that the messages got through to 72-88 per cent of users across the course of the assessment. 80-94 per cent of the members of public used for the trials appreciated that Cell Broadcast was a useful addition to the use of sirens for public warning (the remaining users had their phones switched off when the messages came through). It is clear that Cell Broadcast represents and effective and elegant means for the coordination of public warning during emergencies.