Tsunami Warning System
(This paper has been extracted by presentation to United Nation -
High Level Expert Group meeting
options for disaster management systems - Bangkok June 22, 2005
and further improvements following best practice).
In this technical sheet an innovative and reliable system able to
forecast and measure the arrival of a tsunami is described. It is
the result of several experiences of the Italian company Envirtech
S.p.A. in marine project combining the company competence in the
scientific/environmental field, the newest offshore technologies,
the more advanced electronics and data management and
communication solutions and the knowledge of logistic/operational
aspects related to the installation of sea surface buoys,
underwater systems, control centre and geographical scale alarm
systems. This page concerns only the ocean side
The system is composed of the following main parts:
In underwater monitoring module (UM) installed at the seabed;
a surface buoy (SB) moored in the area of the UM;
an “in water” communication segment connecting the UM with SB;
an onshore centre (OC) hosting a standard PC server;
a satellite communication segment connecting SB and OC.
Two different classes of underwater modules have been
developed to comply with different types of applications.
Basically the two Classes differ for the instrumentation embedded,
in consideration of the distance between the tsunami-genic
sources and the most close coastal regions.
Poseidon Class UM
test at sea
video stream), (see also deployment of
DS2 in the Andaman Sea)
Are standard deep ocean real
time Tsunami monitoring systems based on sea levels measures.
The systems are deployed in free-fall assured to their
buoyancy line, after a brief survey of the seabottom in the
deployment area. Typically the system fall speed measured is 1.6
meter/sec, so to cover 4000 meters the system will need about 40
This devices can be used when the
distance between the coast and the tsunamigenic source consent at
least one hour of early alarm after that the tsunami waves have
been measured. Tipically the deployment distance is more than
1000 Km off shore. The maximum deployment depth is 5000 meters.
Respect to competitors devices the systems have been
improved using a robust stainless steel frame hosting all
components in titanium vessels. A new, very low power
consumption, computer (Arm Technology) and a very powerful
litium power pack capable of two years authonomy have been used.
One paroscientific pressure sensor has been used for tsunami waves
The Poseidon class UM have been designed to be
always recoverable using an indipendent system for ballast release.
In this manner, avoiding to use the same device both for acoustic
transmissions and ballast release, the operators will be
sure to have always a chances to recover the unit after an
eventual system failure or for routine maintenance.
After that a Ballast release command has been dispatched the
underwater module will pop-up from the ocean bottom at a speed of
1.2 meter/sec - An optional radio beacon could be used in addition
to the embedded radar reflector to speed-up recovering of
the device when the ocean surface will be reached.