History
of Undersea Exploration
Since the beginning of time, humans
have had a love affair with the sea. The bounty of the sea has given
up countless scores of fishes that have fed families the world over
for thousands of years. Explorers have braved its waters to discover
fertile new lands and untold riches. But the sea has also been feared,
seeming to “swallow” entire fleets of ships and taking hundreds
of lives without a trace. For many thousands of years, the sea was considered
a watery desert, robbing men of their sanity, and families of fathers,
brothers, and husbands. The sheer darkness of its depths made it impossible
to see into them and gain a glimpse of what lay beneath. The fear of
what lay in the unknown depths won out over curiosity, so that exploration
of the waters beneath the surface was never considered necessary or
reasonable. Occasionally, ocean travelers saw glimpses of deep creatures
that would rise to the surface to display their horrific and bizarre
proportions. Such strange and mysterious creatures gave rise to many
legends of sea monsters, reason enough for people not to consider venturing
into the dark and dangerous abode of the deep.
But with the advent of the Industrial
Age, fear gave way to growing curiosity. Wealthier nations were heady
with the strength of their new technologies, instilling in them a sense
of power and invincibility. No longer feeling like victims of circumstance,
highly developed societies, fat from the wealth of their burgeoning
industrial waistlines, were bent on conquering nature. This new sense
of courage and curiosity gave rise to early expeditions seeking to remove
the veil of mystery that lay beneath the waves. Early explorers attempted
to plumb the depths of the ocean and discover, once and for all, just
how deep the depths really were. The tools that were used to try to
fathom the deep were as simple as a cannonball or large steel weight,
fastened to the end of a long hemp rope that was lowered into the water
until it touched bottom. This proved to be an imprecise and unreliable
method for measuring incredibly deep water and many of the early soundings
(as these measurements were called) came up with some depths that have
since been corrected. Since then many scientific expeditions have brought
back data and specimens that reveal a more complete picture of the undersea
world. One of the earliest and most thorough scientific expeditions
undertaken to map the sea and catalog its unknown life forms was conducted
by the British naval ship, the HMS Challenger.
Challenger
Commissioned by the British Royal Society, the Admiralty, Treasury and
Museum, the HMS Challenger was a naval corvette ship that had been essentially
stripped of its weapons and fitted with every modern scientific instrument
of that time. In December of 1872, the Challenger set sail with 240
scientists, sailors, and crewmen on the most ambitious and comprehensive
study of the sea to date. The purpose of the three-year long expedition
was to
thoroughly explore and catalog the entire depth of the sea all around
the world.
At the time, the increasing interest
in Charles Darwin’s Theory of Evolution had spawned tremendous
curiosity about the nature of life underneath the sea. Early philosophers
and thinkers, aided by the anectodal evidence of sea travelers, theorized
that the very deepest regions of the sea maintained such inhospitable
conditions, that no life could possibly exist there. Known as the Azoic
Theory, this thinking began to come under increasing scrutiny when some
exploratory missions by the British Royal Society had dredged up incredible
numbers and diversity of life forms from depths as far as 3 miles down.
Many of the bizarre organisms that were brought to light had never been
seen before, except in the fossil record. It seemed that the deep harbored
creatures from earth’s distant past and the search for living
fossils began in earnest.
Darwin’s Theory of Evolution,
that biological diversity and the evolution of species was a result
of adaptations to the continually changing environment, breathed life
into the idea that the deep sea should harbor living fossils. It was
felt that the conditions of the deep sea should be as a time capsule,
with relatively little or no change over the course of geologic time.
This unchanging environment was thought to maintain conditions favorable
to the UN-evolution of species – such that creatures dwelling
in the depths of the sea millions of years ago might still exist in
modern times, where they lay undisturbed and undiscovered by man. The
slurry of throwback lifeforms that had been previously dredged up was
evidence that pointed to the possibility of living fossils.
Over the course of the three-year
journey, the Challenger crew made some groundbreaking discoveries that
revealed a much more detailed and thorough picture of the mysterious
abode beneath the waves. For the first time, a clearer picture of the
shape of the sea floor began to emerge. For thousands of years, it was
thought that bottom of the ocean was a vast, unbroken plain that was
flat and shapeless. But after hundreds of soundings taken in oceans
around the world, it was discovered that the sea floor was not flat
at all. In fact, an incredibly long, unbroken chain of mountains rising
up from the sea floor, what is now known as the Mid-Atlantic Ridge,
was discovered. Some of the undersea mounts rose up to just a mile beneath
the sea, looming over a mile high from the sea bed. Detailed soundings
taken around coastlines revealed long, gently sloping shelves radiating
out from shore, which then abruptly dropped off to the deep sea floor,
what are now known as continental shelves. Some of the soundings that
were taken were so incredibly deep, far deeper than any other place
in the sea, that these narrow bands of exceptionally deep undersea terrain
became known as trenches. It was discovered that the majority of the
sea bed consisted of a vast, relatively flat plain just over two miles
deep, which they called the abyssal plain. At the conclusion of Challenger’s
voyage it was clear that the ocean was not at all a bottomless, featureless
domain. The picture that emerged was one of a complex sea floor that
seemed to be a world unto itself, shaped by unknown forces.
After more than three years at sea,
the Challenger had dredged up from the depths 4,717 new forms of life
never before seen by human eyes. Slimy, smelly creatures with grotesque
and nightmarish features, such as extremely long, daggerlike teeth,
enormous, bulging eyes, and body parts that gave off their own bluish-green
light (bioluminescence), were regularly dredged up. Some creatures that
surfaced in Challenger’s trawling nets were throwbacks to earlier
evolutionary time periods and seemed to be missing links between creatures
found in the fossil records and modern ocean dwellers. Just about everywhere
in the sea, all around the globe, at even the deepest of depths, the
Challenger’s trawls and dredges continually came up with numerous
life forms. It seemed even the coldest, darkest, and most inhospitable
regions of the deep sea were easily occupied by incredibly diverse species
that were well-adapted to life in the depths. The Azoic Theory of lifeless
regions of the deep sea had finally been laid to rest.
William
Beebe and the Bathysphere ->