by
Mark Ollig
More
than 550,000 miles of submarine cables currently provide telecommunication and
Internet services between most of the world’s continents.
The
first undersea or submarine cable began providing telegraph service between
Dover, England and Calais, France Oct. 17, 1851.
By
2015, there will be some 285 working submarine cables originating from
land-based stations on one continent, crisscrossing oceans and seas, and
terminating to land-based stations located in other continents, or regions of
the world.
The
importance of these submarine cables cannot be overstated; they are used by
scientists, health facilities, educators, governments, and citizens of the
world.
They
also provide the pathways of commerce for many global businesses.
These
undersea cables furnish the physical venue, or “pipe” for communicating the
social narratives and political ideals, for millions – if not billions – of
people around the world.
Most
of these physical cables are providing their service, while silently resting on
the bottom of the sea, or ocean floor.
The
longest undersea fiber-optic cable; named the South-East Asia
Middle-East-Western Europe 3 (SEA-ME-WE 3), covers 24,000 miles, and includes
39 separate landing points where the cable comes onto dry land.
Besides
providing communications and Internet, a recent report is recommending ocean
monitoring technology be added onto submarine cables.
In
a 40-page report, a joint task force of agencies proposed new uses for
submarine cables.
This
report addresses “The scientific and societal case for the integration of
environmental sensors into new submarine telecommunication cables.”
Many
telecom companies and operators of submarine fiber-optic cables, currently
monitor the electrical and optical power traveling inside those cables.
Whenever
a cable is cut or becomes degraded, the measurements monitored can provide an
accurate location of where the disruption is, allowing a submarine cable repair
ship to be quickly dispatched to perform restorations.
The
report suggests these underwater cables be equipped with sensory devices, which
would provide detailed information about their watery surroundings.
Some
of the information obtained could include measurements of ocean currents and
ground vibrations, using attached accelerometer sensor devices.
By
monitoring the ocean’s water pressure, temperature, and other conditions via
sensors fastened to a network of submarine cables, weather bureaus and other
agencies would be able to obtain immediate information, thus providing advanced
warning to nearby coastal regions which could be affected by tsunamis, for
example.
Environmental
accelerometers, seismometers, pressure gauges, and other sensor devices could
be installed on special ports inside the submarine fiber-optic cable repeaters.
These
repeaters boost the cables power and signal strength over long distances.
Some
fiber-optic submarine cable repeater units are attached every 25 to 100 miles,
and get their power from the fiber cable’s copper tubing. This tubing is
encased within the same protective steel “strength members” which wrap around
the optical fibers.
Specific
sensors installed would notify appropriate agencies in the event of
earthquakes, landslides, and changes in water quality.
The
communication requirements for these sensors are estimated to use a minute
amount of bandwidth, and a data rate of less than 20 kilobit per second (kb/s).
Information
could be monitored regarding worldwide sea-levels, and the heat exchange
between the oceans and the atmosphere.
Non-environmental
hazards, such as a ship’s fishing net or anchor dragging a submarine cable out
of place, could also be detected.
Today,
we are using floating oceanic buoys, earth-orbiting satellites, and ships at
sea to gather information about the oceans; however, not enough deep-sea,
real-time data is being obtained from the ocean floor.
Many
of the world’s submarine cables will be replaced within the next 30 years, so
the case is being made for the “greening” of future submarine fiber-optic
cables, with real-time sensor-monitoring technology, which would last the
expected 25-year lifetime of the new cables.
Submarine
cables have the potential to become, as this report states; “a principal
vantage point for keeping active watch over the Earth’s ocean environment.”
The
report is very detailed, and contains many drawings, charts, photographs, and
source links.
The
research was conducted by the International Telecommunication Union (ITU), the
Intergovernmental Oceanographic Commission of the United Nations Educational,
Scientific and Cultural Organization (UNESCO/IOC), and the World Meteorological
Organization (WMO).
The
complete report can be read at http://tinyurl.com/q2u67or.
My
Winsted readers might be interested to know, in the late 1960s, a submarine
cable was placed along the bottom of Winsted Lake by the local telephone
company.
A
pontoon boat containing the large wooden reel holding the submarine cable,
along with the telephone company crew, slowly made its way across the lake,
traveling west to east.
As
the submarine cable was pulled from the reel, heavy steel bolts were strapped
onto it about every 10 feet, which weighed down the cable as it was slowly
lowered into the murky depths of Winsted’s most famous body of water.
For
many years, this submarine cable reliably provided telecommunications service
from the telephone company’s downtown central office, to the subscribers
located on the east side of the lake.
Winsted Lake Submarine Cable