It seems to me the most difficult part of any warning system (The Big Picture, 14 January) is to get any government alert out to all locations that might be affected.
For holidaymakers on many of the world’s beaches, neither TV nor radio broadcasts could reliably reach them.
Warning sirens dotted along the coast would be very expensive and need regular maintenance for an event that might happen once in 100 years or more.
But in areas within a mobile phone cell the solution could be to alert people, albeit with some investment, via their mobiles. all the cells that cover the coastal areas could be identified and a message sent to all phones in that cell with a suitable text or message warning: ‘tsnmi wthn two hrs mov hi grnd’.
Once developed, the same solution could be applied almost everywhere with virtually no hardware infrastructure.
The method would work for very many parts of the world, including many of the places that were recently devastated. It would certainly work for the east coast of the US which is said to be under threat from the Canary Islands.
It would not, of course, be a solution for villages in such places as the west of Sri Lanka or Indonesia where mobile phone ownership is probably low. There, a siren activated over the phone network would be needed.
Isle of Wight