THE Cold War is over. The nuclear threat has faded. And with a shortage of
enemies to play underwater hide-and-seek with, America鈥檚 admirals can lie back,
relax and think about what they can do for science. For while America鈥檚 military
men have had access to advanced technologies that provide them with vast amounts
of information about the oceans, civilian scientists have only ever been able to
dream of getting their hands on such technology. Now the fog of secrecy is
clearing and eager marine scientists are queueing up to ask for a look in the US
Navy鈥檚 storehouses of oceanographic data.
In the past, such requests would have been greeted with stony silence. But
the US Navy is beginning to unbend鈥攁nd unwrap a few of its best kept
secrets. Both civilian and naval scientists agree that the new openness should
help to improve scientific understanding of the oceans and important phenomena
that are intimately linked to it, such as global warming.
This is no small concession: observations of the oceans are some of the most
highly classified of the US military鈥檚 secrets. Almost since the beginning of
the Cold War, the US relied on the sea as a hiding place for much of its nuclear
arsenal. At the same time, the US wanted to be able to find Soviet submarines
that were hiding in the depths. Routine measurements of physical conditions in
the ocean, the water鈥檚 density, temperature or salinity, for example, were
crucial in discovering how well the water would transmit sound and so for
interpreting the noises made by enemy submarines. Detailed observations of the
seafloor could suggest cosy hiding places for subs on both sides.
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Now, the US Navy is learning to live with civilians鈥攍iterally in some
cases. A small band of marine scientists has been hitching free rides under the
Arctic ice in a Sturgeon-class nuclear attack submarine. The US Navy has carried
civilians and their instruments on two cruises so far, in 1993 and 1995, and has
agreed to one cruise a year for the next four years.
鈥淓ven though the Navy has been conducting research in the Arctic for decades,
it has by and large been classified,鈥� says Ted DeLaca, director of the office of
Arctic research at the University of Alaska, Fairbanks. DeLaca was the chief
scientist on the 1995 cruise aboard the USS Cavalla, which covered 20 000
kilometres within the Arctic Ocean over 44 days in April and May 1995.
The observations from these missions are almost unclassified鈥攂ut not
quite. Still wary of revealing the exact capabilities of its attack subs, the US
Navy forbade any mention of the subs鈥� top speed or how deep they dived. And
although the vessels were largely at the scientists鈥� disposal once in the
Arctic, they were effectively 鈥渂lindfolded鈥� on the journey to and from the study
site and barred from making any observations en route.
Despite this, DeLaca says the two submarine cruises so far have been
鈥渇abulously successful鈥�. On his cruise last year, the Cavalla surfaced through
the ice several times so that the researchers could draw water samples and drop
off automated instruments such as weather stations. As the sub cruised through
the water, instruments mounted in its conning tower continuously measured the
conductivity and temperature of the water.
Along the way, the submarine also released more than 100 expendable sets of
instruments which provided a rough picture of the water conditions to a depth of
about 1000 metres. While submerged, the sub gathered gravity and bathymetric
readings. By the end of the trip, the oceanographers had completed a geophysical
survey of the Chuckchi Borderland north of Alaska, a straight-line survey from
near Point Barrow, Alaska, to north of Franz Joseph Land, and a survey of the
Lomonosov Ridge north of Russia.
One of the great advantages of a sub is that it can go just about anywhere,
reaching parts that other ships can鈥檛. 鈥淲ith an icebreaker, you don鈥檛 go exactly
where you want to go, when you want to go there,鈥� says DeLaca. 鈥淵ou kind of
crunch your way through.鈥�
But it wasn鈥檛 all plain sailing for the scientists. The US Navy, they
discovered, was prepared to go so far鈥攂ut not quite far enough. Even with
civilians aboard, the subs are on active duty and carry a full stock of weapons,
so conditions were somewhat cramped. The scientists were not allowed to make any
physical modifications to the ship to suit their operations. Nor were they able
to use sonar or other noisy instruments in case they gave away the sub鈥檚
position.
Faced with such restrictions, says DeLaca, they had to adopt some fairly
rudimentary approaches to gathering data. To collect water samples, for example,
they had to interrupt the journey and come to the surface to drop sampling
bottles on a line. They were barred from collecting while submerged because they
were not allowed to reveal the depth at which the sub was cruising. 鈥淚n many
ways, we were doing turn-of-the-century oceanography using an elegant ship,鈥�
says DeLaca.
But the free rides have given oceanographers a glimpse of what might be
possible with a nuclear sub鈥攊f only they had one of their own. This may
not be quite so crazy as it sounds. The US Navy is in the process of retiring
its fleet of Sturgeons and, with torpedoes and missiles removed, a second-hand
sub would offer plenty of room for state-of-the-art instruments. With their own
Sturgeon, oceanographers could do whatever they liked. 鈥淣obody would care
because you wouldn鈥檛 be hiding from anybody,鈥� says Garrett Brass of the US
Arctic Research Commission, which is badgering the US Navy to turn over a
Sturgeon to science. 鈥淎s successful as the cruises have been, there鈥檚 much more
science that can be done,鈥� says Brass.
But nuclear subs don鈥檛 come cheap. The estimated bill for overhauling a
Sturgeon for civilian science is between $50 million and $200
million, with operating costs of perhaps $10 million a year. The National
Science Foundation鈥檚 annual budget for all ocean sciences is about $190
million.
The thaw in relations with the military has set other ocean scientists
thinking. The US Navy probably has a lot more technology monitoring the oceans
than it admits to. But one bit that would come in handy is its network of
sensitive underwater microphones. These were planted on the ocean floor to
listen to the movements of Soviet nuclear submarines. Some civilian researchers
have already been given access to data from some of these hydrophones, for
projects such as tracking migrating whales by listening to the sounds they
make.
But the US Navy is closing down the network in the name of economy, and ocean
scientists see a great opportunity slipping away. They would like to use the
hydrophones for many different types of study but particularly to monitor
earthquakes in the seafloor. 鈥淥n land we record seismic data continuously, but
there are no comparable long-term records for the oceans,鈥� says John Orcutt,
head of geophysics at Scripps Institution of Oceanography in La Jolla,
California. 鈥淭here is an opportunity now to use the surplus arrays, to turn them
on and record for a decade.鈥� If the hydrophones are left switched off for long,
they will deteriorate and it may be impossible to reactivate them later.
More exciting is the prospect that civilian researchers might soon get their
hands on the huge volumes of environmental data the US Navy has collected from
the oceans over the years. In 1993, the Environmental Task Force, a committee of
civilian scientists with security clearance who advise the government, began
trying to prise the data out of the Pentagon. The task force wanted wider access
to images from spy satellites and other military secrets.
Last year, a second panel known as MEDEA piled on the pressure, demanding the
release of much of the oceanographic data, including measurements gathered from
ships and planes as well as satellites. With access to these databases, the
experts argue, marine scientists would make huge advances.
The world caught a glimpse of the treasure hidden in the US Navy鈥檚
archives last year when all the data gathered by the Geosat satellite was
declassified. Between 1985 and 1989, a radar instrument aboard Geosat measured
the altitude of the ocean surface. These measurements allow US Navy scientists
to work out subtle changes in the strength of the Earth鈥檚 gravitational field.
Changes in the height of the sea surface are caused in part by small changes in
the gravity field, for example, when it is deflected by a large mass of dense
rock just below the seabed.
The data were originally collected to improve the aim of nuclear
missiles launched from submarines. But changes in gravity also show where
features of the seafloor are disrupting the gravity field, providing a detailed
topographical picture of the ocean floor. A Geosat map issued after the data
were declassified shows mountains and canyons that had never been seen before.
鈥淭he map is a major advance in our understanding of the oceans,鈥� says James
Baker, head of the US National Oceanic and Atmospheric Administration. 鈥淚t may
force revisions of plate tectonic theory, because plates making up the Earth鈥檚
crust do not appear to be as rigid as previously thought.鈥�
A new Geosat satellite is planned for launch later this year, and this time
the US Navy has promised to make the data available almost immediately.
Despite the thaw, there is still a vast mass of information that civilian
scientists long to see. The US Navy鈥檚 datasets with the greatest scientific
importance include measurements of gravity strength, which reflect the
geological structure beneath the seafloor; magnetic fields, which could reveal
tectonic plate movements; the thickness of ice in the Arctic; seafloor images;
and measurements of sea height. Most of this information is wholly or partially
classified.
Of course, the US Navy is not the only arm of the government with supersecret
satellites: spy satellites operated by the US National Reconnaissance Office
might also provide valuable data for oceanographers. Observations from 鈥渘ational
overhead systems鈥� (spook-speak for spy satellites) 鈥渃an lead to better data on
local winds and other meteorology, bathymetry, oceanic fronts and tidal
currents, as well as general circulation and upwelling areas,鈥� says Lawrence
Gershwin, the CIA鈥檚 national intelligence officer for science and
technology.
MEDEA scientists鈥攁ll vetted by the CIA鈥攁re already trying to use
spy satellites to track global ocean circulation patterns and flow patterns in
coastal areas. 鈥淭his information is difficult or impossible to generate with
other existing remote-sensing systems,鈥� says Gershwin.
Old habits die hard, however. And even as the admirals try to adjust to the
idea of sharing information, there is a new secret programme of data collection
in the offing. The US Navy believes that its future lies in coastal warfare and
that it needs to do much more basic oceanography to prepare for that
battlefield. The advice from MEDEA is that the Navy should carry out a long-term
study of selected sites in the ocean on a scale that civilian oceanographers
could only dream of. In this case there would be no concession to greenness:
data gathered by state-of-the-art sensors would remain securely 鈥渂lack鈥�, or top
secret, for the foreseeable future.