I will talk about cables
telecommunication
I try to say it like that it’s not
very sexy but know that these are
cables there would not be the internet
we know today
you must have all heard
of the cloud this famous virtual entity
vaporous in which all our
digital data dwell there
well this cloud is internet
in fact it’s just servers
interconnected by wires and when
his sons must connect continents
his sons these are the cables of
telecommunication cables
submarines laid at the bottom of the sea in
the mud know said it’s not very sexy
but again without these cables
no internet
so it’s well worth it
speak a little bit of these cables and that
been a while in that poses
cables at the bottom of the sea the first
underwater cable
he was laid for telegraphy
it was in 1850 and it was between
France and England
it was a big copper cable he
lasted only a few hours
he transmitted some messages and he
could transmit up to 12 words per
minute
a modern cable
it’s a cable that will have a duration
life of 25 years who can transmit
up to several dozen tera
bytes per second
give you an idea it’s several
hard drives transmitted in a second and
a modern cable
today it looks like that it’s
not very big it’s not bigger than a
garden hose
it’s a metal cable covered with
plastic and in the middle of this cable he
are fiber optics and its fibers
optical
they can transmit quantities
phenomenal information under the
form of light pulses and as
these light pulses are going very
quickly in the cable the information can
cross entire oceans in a few
milliseconds
that’s how we can see in
streaming excellent videos
video that are stored on
servers at the other end of the planet
it is estimated that 95% of internet traffic
global is through these cables of
telecommunication in the bottom of the
oceans
there are 1 million kilometers that
is seated at the bottom of the oceans 1 million
km is enough to make 25 times the
turn of the earth I’m talking to you about
telecommunication cables but in
it’s not my domain at all
I am an oceanographer
I am the researchers and engineers and
my domain is oceanography
physical is the study of the currents of
waves of sea level swamps and
exceptional phenomena such as
tsunami is my specialty in this
domain is the observation
because in the ocean it’s often in
observing it we understand but the ocean
its vast is very deep more than
4000 meters on average and it’s happening
lots of things
so if we want to understand what is there
pass it must be able to measure at the
good place at the right time
even if ultimately what we measure
it’s simple parameters like
temperature or pressure is
today measure the temperature these
critics in the context of change
because of our emissions from
greenhouse gas one observes a
global warming and
of its oceans and to observe this
ocean warming
we have several tools we have
satellites that rotate constantly
around the planet and who are they going
measure the surface the temperature at the
ocean surface
we have floats and ships
oceanographic studies that will measure
from time to time the temperature in the middle
from the ocean but we have very few
data at the bottom of the ocean in
the ocean also measures the pressure is this
that when we measure the pressure at the bottom
of the ocean
in fact we measure the weight of the water and
the weight of the water it tells us about
sea level and as part of the
climate change and well at the
of the town hall goes up because
the oceans are warming
so they take up more space and the
sea level it goes up because there is
more water in the oceans because of
melting glaciers if we measured the
pressure at the bottom of the oceans in fact one
would understand better where and how the sea
mounted
and then also tsunamis tsunamis
are particular waves when
they are off in the ocean
deep
they are very small but they
go very fast it’s when she arrives
at the coast it slows down and
that she can become very tall and
today we measure tsunamis but
when they are already at the coast
if only we manage to measure
tsunamis off before they arrive
we would have more reliable forecasts
and more quickly but we know how
to measure the tsunami off
but we do not do it because it’s
with systems that are so expensive that
it’s not possible
you’ll understand it’s missing
a lot given to the bottom of the oceans and
the coup may have said you also do
that we could not take advantage of
hundreds of thousands of kilometers from
cables that are laid in the bottom of
oceans
and well no we can not enjoy it
because today these cables are
deaf and blind to their environment
there may be a solution all to
the hour I spoke to you impulses
luminous traveling in the fibers
optical cables and well these fibers
these light pulses when she
journey she gets tired and it takes them
restore energy every
fifty to two hundred kilometers in
amplifiers we call
repeaters in these repeaters the
tired light pulses arrive
they are re amplified then they are
sent back to the next one to petter and
so on to be able to cross
of the entire oceans these repeaters have
access to the fiber and they are
supplied by the
cable the idea seems so simple on
could install sensors from
temperature and pressure in the
cable repeaters
telecommunications it would be powered
in electricity by the cable and he
will transmit their data in
optical fiber
we could cover the majority
oceans and we could respond to
important societal issues
like global warming
rising sea level the
prevention of natural disasters
for tsunamis for example when a
tsunami arrives it’s too late to
protect the facilities and by
against it can put the population to
shelter
and when we talk about evacuation have a
tsunami
every minute counts to be able to save
lives and we’ve already shown that if
we had wide pressure sensors
we could give the alert up to 25
% faster
the idea seems so seductive but it
there are many obstacles
there are order obstacles
technological barriers
and financial hurdles in terms
technological
temperature sensors and
pressure are very instruments
fragile so before you can put them
in the repeaters they have to
can cash
the violent treatment that is suffered by
repeaters when they are posed at
bottom of the sea by ships
specialized and believe me this
treatment is very violent nothing to
see with the way we
oceanographer
we treat these instruments we
treat like crystal vases on
transports them in boxes in
foam are gently removed
bottom of the sea in legal terms the
telecommunication cables are
very protected as part of the
united nations convention on
more protected right of the sea
that ocean measurement systems
I know it sounds weird but it’s
one of the biggest obstacles
if we ever put sensors on
the cables the caps would lose some
of their legal protection and there is
obviously financial hurdles
because the operators or the
cable owners they did not pull
no commercial profit from
installing sensors on their
cables but things are moving forward since
2012 it’s a small group of
scientists of the jurist and
industrialists who seek and who
find solutions to these obstacles
manufacturers produce
sensors that are more resistant to
international agreements are signed
between countries to be able to exchange
freely the scientific data and
potential donors have
been identified
the next step is to facilitate the
laying the first smart cable this
first smart cable will serve as
demonstrator and will show the utility and
the feasibility of these cables
smart ideally it will be a
cable between two countries or two there
only and with the rise of the Internet of
new cables are laid every
years in the world
is the first smart cable
will be asked in the Pacific
I do not know but I am convinced
of one thing is that when it will be
do we say to ourselves but why we did not
makes a great thank you
[Music]
[Applause]
”
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