Why are modern communication services used rather than older ones .How effective were each of the
services given their purpose :

New generation tecnology devices which help detecting trsunami are :
 1) NASA's GPS-based prediction of the tsunami.


2)The Compatt 5 may be deployed in water up to seven thousand metres (more than four miles) deep and
it is fitted with a sensor that continuously monitors water pressure, saving data every fifteen minutes...


3)there are various geological stations which monitor seismic activity, so when an earthquake is detected
(tsunamis can be created by a rupture in a fault line) the tsunami can be detected.

this is the gps system which helps track tsunami .