Listing slightly, S. P. Lee returns with scientific booty
Gather round and I'll tell you the tale of the voyage of the Samuel P. Lee. She was a tidy craft of 1,300 tons when she steamed out under the Golden Gate Bridge in the summer of '83, tidy despite the clutter of millions of dollars of fancy, scientific gear aboard designed to wrest the secrets of Neptune's mineral treasures from his grasp.
When the Lee tied up back at her home port here last Tuesday (Feb. 26) -- more than a year and 35,000 miles later -- the 208-foot vessel was listing slightly and noticeably battered. But with a layover for repairs in Hawaii, including a touch up of her paint, she was still a proud sight.
As the chief research vessel of the US Geological Survey (a group better known for its land-lubberly operations), when the Lee set out, her crew had set itself an ambitious goal: a cruise that would range north to the Arctic, through the islands of the South Pacific, south to the Antarctic, and back again.
From the first, it was clear that the challenges they would face were not just those of the not-always-Pacific Ocean, but also the type created by politicians and budget directors. The ship had enough fuel to last until October, the next fiscal year. Where the money would come for operations after that was an open question.
``If you waited until you knew where all the money is coming from, you would never leave the dock,'' maintains David Howell, the dark-haired and energetic chief of the USGS Pacific Marine branch. He managed to ``daisy chain'' a number of different programs and funding sources into a successful 12-month, $12 million expedition.
Like the story of any genuine voyage of discovery, the Lee's is a tale of adversity overcome. In her case, the problems began before she left the dock. In the fall of 1982, while Dr. Howell was busy drumming up money for the voyage, heavy rains and winds breached the dike protecting the Lee's harbor and the waves ruined $4.5 million in electronic equipment stored in a warehouse nearby.
Once under way, the ship's nemesis proved to be ice. In northern climes, unusually heavy flows kept her out of the Arctic Ocean, where the scientists onboard had expected to search for geologic basins of the type where petroleum is found.
At the antipodes, the Lee had even more icy adventures. Trying to reach the US Antarctic base on McMurdo Island, she got stuck in the ice, despite the assistance of a Coast Guard icebreaker. The icebreaker helped free her and then ferried scientists and supplies out to the ship while she waited beyond the ice. A few days later, the crew discovered the encroaching ice had bent her propeller, but a chilly dive by the ship's captain revealed the damage minor enough to continue.
A few days later, while cruising the Ross Sea, an iceberg neatly severed most of the 2-mile-long cable the Lee was towing. This was filled with hydrofones and complex electronic circuitry and was worth half a million dollars. Maneuvering quickly, the captain brought the vessel back to the point where the cable was lost in time to snag the buoys marking its end before they went under.
Just as there were trials overcome, there were the rewards of discovery. In this case, the ``terra incognita'' being explored was the Pacific sea floor. This makes up some 40 percent of the Earth's surface and remains the least mapped.
``The Pacific is virtually untouched. It is difficult to go out and not find something new,'' explains H. Gary Greene, the USGS scientist who served as project coordinator.
Of course, penetrating the ocean depths requires sophisticated equipment. But the Lee was outfitted specifically for the purpose.
One of the ship's key instruments is an airgun that fires underwater with the force of six sticks of dynamite. These detonations create powerful pressure pulses that penetrate the seabed and are reflected back by various rock layers. When these reflections are picked up by sensitive hydrofones and processed by computer, they draw a portrait of the rock layers thousands of feet below the sea floor.
Another type of tool are deep-sea dredges, which pluck samples from the ocean floor -- a process one of the scientists described as similar to standing on the top of a 10-story building while trying to pick up sand grains from the sidewalk below with a thimble attached to a long length of thread.
One piece of ultrasensitive equipment onboard detects subtle changes in the gravitational field that help distinguish between the lighter, sedimentary rocks where petroleum is likely to be found and heavier rock types.
Using its sophisticated scientific gadgetry, the Lee made several important discoveries. In the Line Islands, south and west of the Hawaiian chain, the Lee sampled a number of undersea mountains. The crew found them encrusted with a mineral that contains up to 2 percent cobalt and minute but economically significant amounts of platinum. The cobalt concentrations, twice what had been expected, are significant. Cobalt, used in making high-strength steel, is a strategic mineral -- 90 percent of which the US imports. As a number of these sea mounts are in the US economic zone, the federal government is already gearing up to grant licenses to companies interested in mining the area.
As the ship cruised off of Tonga, its scientists confirmed that the area contains a large basin of the sort where petroleum is found. While this isn't the type of area where giant oil deposits are discovered, a number of oil companies have been attracted, reports USGS researcher David Scholl. Commercial oil development would greatly help the small country with its foreign exchange problems and reduce the burden that expensive imported fuel places on its economy.
Exploration off Tonga, what Captain Cook called the ``Friendly Islands,'' also produced a major scientific surprise. A magma chamber was discovered just beneath an undersea ridge.
The hot water heated by such a chamber leaches minerals out of the rock and, then as the water cools the minerals precipitate out and rain to the sea floor. This is thought to be the way all ore deposits were originally formed. The area appears to have been active for 6,000 years and so has had time to build up valuable deposits, says Dr. Scholl. But further investigation will be required to see if this is the case.
More than 100 scientists from 10 countries besides the US took part in the Lee's voyage, rotating onboard every two months or so. So much scientific data were gathered that it will take a year to analyze it all, the scientists involved say. At this point, the S. P. Lee's future travels are uncertain. ``But we simply can't leave it at this,'' comments Dr. Greene, clearly bitten by the exploration bug. -- 30 --