Download Steely-Eyed Hydronauts of the Mariana

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Marine pollution wikipedia , lookup

Oceanic trench wikipedia , lookup

Anoxic event wikipedia , lookup

Physical oceanography wikipedia , lookup

Effects of global warming on oceans wikipedia , lookup

Marine biology wikipedia , lookup

History of research ships wikipedia , lookup

Sea captain wikipedia , lookup

Dive planning wikipedia , lookup

Marine habitats wikipedia , lookup

Maritime transport wikipedia , lookup

Ocean wikipedia , lookup

Deep sea fish wikipedia , lookup

Abyssal plain wikipedia , lookup

Challenger expedition wikipedia , lookup

Transcript
Steely-Eyed Hydronauts of the Mariana
Written by Alan Bellows on 21 July 2009
(The crew of the HMS Challenger,
1874)
On 21 December 1872, the British
naval corvette HMS Challenger sailed
from Portsmouth, England on an
historic endeavor. Although the
sophisticated steam-assisted sailing
vessel had been originally constructed
as a combat ship, her instruments of
war had been recently removed to
make room for laboratories, dredging
equipment, and measuring apparatuses. She and her crew of 243 sailors and scientists set
out on a long, meandering circumnavigation of the globe with orders to catalog the
ocean’s depth, temperature, salinity, currents, and biology at hundreds of sites–an
oceanographic effort far more ambitious than any undertaken before it.
For three and a half long, dreary years the crew spent day after day dredging, measuring,
and probing the oceans. Although the data they collected was scientifically indispensable,
men were driven to madness by the tedium, and some sixty souls ultimately opted to
jump ship rather than take yet another depth measurement or temperature reading. One
day in 1875, however, as the crew were “sounding” an area near the Mariana Islands in
the western Pacific, the sea swallowed an astonishing 4,575 fathoms (about five miles) of
measuring line before the sounding weight reached the floor of the ocean. The bedraggled
researchers had discovered an undersea valley which would come to be known as the
Challenger Deep. Reaching 6.78 miles at its lowest point, it is now known to be the
deepest location on the whole of the Earth. The region is of such immense depth that if
Mount Everest were to be set on the sea floor at that location, the mighty mountain’s
peak would still be under more than a mile of water.
Nothing was known of what organisms and formations might lurk at such depths. Many
scientists of the day were convinced that such crevasses must be lifeless places
considering the immense pressure, relative cold, total lack of sunlight, and presumed
absence of oxygen. It would be almost a century before a handful of inventors and
explorers finally resolved to go down there and take a look for themselves.
The view at Challenger Deep (artist’s rendering)In the years that followed the Challenger
expedition, subsequent surveys of the region ascertained that the Challenger Deep is part
of a much larger formation, the massive Mariana Trench. This 1,580 mile-long trench is
the result of the Pacific tectonic plate subducting beneath the Mariana Plate, and the
water pressure at its floor is so difficult to comprehend that it is oft described with
incomprehensible analogies as “the weight of fifty jumbo jets,” “the weight of 1,600
elephants on every centimeter of your body,” or “all life as you know it stopping
instantaneously and every molecule in your body exploding at the speed of light.”
The first scientist with the know-how and wherewithal to seriously consider a dive to the
bottom of the Mariana was Auguste Piccard, a Swiss professor, physicist, and inventor of
some repute. In the early 1930s, he had gained considerable scientific fame by
constructing and piloting the world’s first manned stratospheric balloon, using a
pressurized sphere and helium gasbag of his own design to reach altitudes than no human
had previously attained. From over 70,000 feet, he conducted experiments to measure
cosmic rays, and made measurements to help prove the theories of his friend Albert
Einstein. Piccard’s wife–mortified that a middle-aged man would repeatedly subject
himself to such risks–insisted that he retire his ballooning career. Much to her surprise, he
agreed.
It turned out that he had grander plans afoot. Piccard had realized that a variation of his
stratospheric balloon concept could be used as a deep-sea diving apparatus, and he soon
set to work constructing his first bathyscaphe vehicle. The contraption consisted of a
high-pressure passenger sphere suspended beneath a different kind of gasbag–a steel float
chamber filled with gasoline. Gasoline is much lighter than water, causing it to be
buoyant; yet it does not compress as air would, which allowed the tank to resist crushing
even at extreme depths. The bathyscaphe operated a bit like an underwater zeppelin:
operators descended by using pumps to replace small portions of gasoline with seawater,
thereby reducing buoyancy. To ascend, operators used controls to let loose some of the
onboard iron pellets used as ballast, thereby increasing buoyancy. Small electric
propellers provided horizontal navigation.
(Auguste Piccard looking through a cone of
Lucite (Plexiglass))
Piccard finished his prototype in 1948, and
conducted a number of unmanned test
dives as far as 10,000 feet. In 1950 he sold
the vehicle to the French Navy in order to
begin construction on an improved design,
the bathyscaphe Trieste. The new vehicle’s
thirteen-metric-ton pressure sphere could
accommodate two passengers–albeit quite
cramped–and included oxygen tanks,
rebreathers, and carbon dioxide scrubbers.
Its hull was five inches thick, and it had a single, five-centimeter-wide window made
from a thick cone of lucite–the only transparent material capable of withstanding the
depths this vehicle was intended to reach. After the craft had undertaken a number of
successful test dives, the US Navy purchased the Trieste and shipped it to the Marianas to
use it in Project Nekton–a series of dives into the ocean’s deepest, darkest recesses to
gather information regarding sunlight penetration, underwater visibility, transmission of
man-made sounds, and marine geological studies of the trench.
On 23 January 1960, two men clambered aboard the Trieste for its attempt to dive into
the Challenger Deep of the Mariana Trench: marine specialist Lieutenant Don Walsh of
the US Navy; and oceanographer Jacques Piccard, son of the vehicle’s inventor. At 76
years of age, Auguste himself was unable to take part personally. The two hydronauts
were expected to be confined in their battery-powered pressure sphere for over eight
hours, including almost four hours each for the seven-mile descent and re-ascent. Since
no manned or unmanned vessel had ever braved the journey to the Challenger Deep, no
one was sure how much life, if any, would be found there. Most scientists were
reasonably sure that microorganisms would be found, but some thought it unlikely that
vertebrates could withstand such an inhospitable environment.
The men engaged the pumps to fill the ballast tanks with water, and the Trieste slipped
beneath the waves to begin its long descent. It only took about sixteen minutes for the
explorers to enter the aphotic zone–the depth at which no light from the surface is
present–and the world outside the tiny window was left in utter darkness aside from the
occasional faint flicker of phosphorescent organisms. From time to time the Trieste
would slow and stop as she encountered a deeper, colder thermal layer, and more
gasoline had to be pumped from the float chamber in order to continue the descent.
The two men periodically reported their progress via a sonar-based phone handset,
however there was little to report aside from the rapidly rising readings on the pressure
gauges and the falling readings on the thermometers. The warmth inside the uninsulated
sphere steadily dwindled.
Partway into their long descent, Walsh and Piccard grew alarmed when they discovered
they were no longer able to raise the mother
ship on the sonar/hydrophone
communication system, even after repeated
attempts. The two men were thus left truly
isolated from the outside world. Curled up in
the cramped, cold, and dimly-lit sphere, the
adventurers continued their hours-long
downward journey with only one another’s
voices and the occasional pop or groan from
the Trieste’s strained hull to punctuate the
anxious silence.
(The Trieste out of water)
At approximately four hours into their descent–several thousand feet above the sea floor–
a sharp clang sounded through the pressure sphere and the vehicle shuddered violently.
Once their wincing subsided, the men did what they could to inspect the craft and its
condition. It seemed that the water pressure at this never-before-encountered depth–six
tons per square inch–had cracked the outer pane of the lucite window. For the moment
the vehicle itself remained watertight, but the damage was worrisome. The Trieste was
outfitted with a few safety systems; for instance, the ballast doors were held closed by
electromagnets, so in the event of electrical failure the doors would fall open and drop the
ballast, causing the vehicle to rise to the surface. But such systems would be of no help to
the men inside if the 1,000 atmospheres of pressure crushed their delicate passenger
compartment. Moreover, no other vehicle in existence was capable of reaching such
depths, which meant that if her float tank became compromised there was no chance of
rescue. Nevertheless, the stalwart scientists opted to press on.
(Lt. Don Walsh and Jacques Piccard inside the
Trieste pressure sphere)
About three quarters of an hour later, the
bathyscaphe Trieste made history as its hull came
to a gentle rest on the silty floor of the Challenger
Deep abyss. The Trieste and her crew had spent
four hours and forty-eight minutes in transit. The
bathyscaphe instrumentation indicated a depth of
37,798 feet and external pressure of 1,099
atmospheres–approximately eight tons per square
inch. The scientists flicked on the exterior lights to
cast light on a patch of earth that had not been
illuminated in millions of years, and peered out
through the peephole. Through the swirling clouds
of agitated silt and sediment the pair could make
out a flatfish which had been disturbed by the
vehicle’s unexpected touchdown. They also spotted
some shrimp and jellyfish swimming nearby. These observations proved that the water
even at such depths was not stagnant and stationary–there was sufficient ocean current to
bring in oxygen for complex life. The mission was not equipped with cameras, however,
so the historic exploratory moment was sadly left unphotographed.
Walsh and Piccard attempted to use the sonar/hydrophone handset again, and found that
it had inexplicably regained function. They reported their arrival and observations to the
mother ship, and although their voices took approximately seven seconds to cross the
seven miles of water, they came through quiet yet clear. The hydronauts observed the
“diatomaceous ooze” through their tiny, cracked window, shivering in the 45F degree
cold and munching chocolate bars to regain lost calories. For the most part, the few
organisms they observed were little different from those found in the miles of water
above them. Thirty or so minutes later, concerned that the damaged lucite porthole would
not withstand the pressure indefinitely, the men dumped two tons of iron ballast and the
vehicle slowly began to rise. Three and a quarter uneventful hours later, the bathyscaphe
Trieste bobbed to the Pacific surface, having entered the history books with a record that
could never be bested. Walsh and Piccard had been to the abyss and back.
Later the same day, the US Department of Navy issued a press release boasting that “the
United States now possesses the capability for manned exploration of the sea down to the
deepest part of its floor.” Project Nekton was a success. Jacques Piccard and Lt. Don
Walsh were flown to Washington DC to receive decorations from President Eisenhower,
and to retell the story of their descent of alternating boredom and terror.
Grand plans were hatched to do further
research with the intrepid bathyscaphe,
including bringing back samples of water, soil,
and organisms from the abyssal trench. The US
Navy, however, was less enthusiastic. The
millions of dollars they had invested in the
mission had not borne any particularly
compelling scientific fruit aside from proving
that such a dive was possible. Perhaps most
importantly, they had demonstrated America’s
deep-sea dominance to the pesky Soviets.
Moreover, the public’s fickle attention was
fixed rather firmly on the developing Space
Race, leaving little interest in oceanic
exploration.
(Closeup of the Trieste pressure sphere and ballast-dropping system)
For a few years the Trieste continued her career as a diving vehicle, though never again
to such depths as the Challenger Deep. Most of her later missions were pedestrian by
comparison, although when the nuclear submarine USS Thresher was lost at sea in 1963
she did participate substantially in the search efforts. Soon thereafter she was retired, and
many of her systems were incorporated into other dive vehicles. Much of her outer hull
was left intact, however, and it is currently on exhibit at the Navy Museum in
Washington, DC. In the 45 years since the Trieste was taken out of service, there has not
been another manned dive vehicle capable of reaching the floor of the Mariana.
Even today, less than 5% of the Earth’s oceans have been explored by humans according
to the US National Oceanic and Atmosphere Administration. Of course humanity has not
entirely abandoned the exploration of the deep. In 1995 a robotic probe did finally revisit
the faraway floor of the Mariana trench, as did another such probe in 2009. Though we
must not diminish the achievements of those plucky remote-controlled explorers, it seems
a shame that no humans have ever attempted to return. There are some people who say
that there is little value in sending humans to harsh places where hardier robotic proxies
can go in their stead; but for the indefatigable adventurer, that sort of stick-in-the-mud,
stay-at-home complacency is unfathomable.
QUESTIONS – Answer in full sentences to receive full value
1.
2.
3.
4.
5.
6.
What type of ship wailed from Portsmouth, England?
Why did the ship and 243 sailors go on this adventure?
How long did their adventure last?
Why did 60 people jump ship?
How deep is the Challenger Deep? What do they compare it to?
What assumptions did scientists make about organisms/life at the bottom of the
ocean?
7. How long is the Mariana Trench, and what formed it?
8. How much water pressure is at the ocean floor?
9. Who was the fist scientist to try to dive the Mariana? When was it? What did he
create? How deep could he go?
10. How did the bathyscaphe work? When did Piccard finish it?
11. Describe the Triste.
12. What was Project Nekton?
13. Who were the two hydronauts that made the voyage into the Challenger Deep in
1960?
14. How long did it take the scientist to reach the aphotic zone? What is the aphotic
zone?
15. Opinion: Would you have stayed in the Triest when you discovered that you were
unable to communicate with the ship above? Explain.
16. What happened to the ship four hours into their descent?
17. How long did it take them to reach the Challenger Deep floor? How deep was it?
How much pressure was the ship experiencing?
18. What were three things that they saw? Are there any pictures?
19. Why did the US Navy not want to spend more money on exploring the deep?
20. Who was the US in competition with? What was the public more interested in?
21. Has another vehicle reached the floor of the Mariana?
22. What percentage of the Earth’s oceans has been explored by humans?
23. Why do you think that the author chose this title? Do you think it is appropriate?
Would you change it? Explain.
Value: 40