`Ivans' put seismic ear to US soil

THE scent of Russian tea blends with the drone of country-western music on the radio at this desert site on the California-Nevada border. A group of Soviet scientists and technicians are monitoring equipment they hope will prove that the superpowers can verify a ban on the testing of nuclear weapons.

The work is part of an unprecedented exchange between independent American scientists and members of the Soviet Academy of Sciences. They are testing the limits of seismic technology in detecting small underground chemical explosions and, by extension, nuclear blasts.

American scientists conducted similar tests in the Soviet Union last fall. Now the Soviets have brought their men and machines to this remote area, which is not far from where the US secretly tests nuclear weapons in Nevada.

Whatever the outcome of the visit, just the presence of Russians amid the pinon and juniper 115 miles from the Nevada Test Site underscores how far US-Soviet relations have come since the days when the countries were exchanging diatribes instead of delegations. It also presents a colorful pageant of East meeting West - Ivans in John Wayne country.

``This is a historic place,'' says Sergei Negrebetsky, one of nine members of the Soviet team, sitting in a trailer filled with Bulgarian, East German, and Soviet equipment, ``the first place where Soviet seismology equipment has been installed on American soil.''

Officially, the visit means little. The exchange is being jointly sponsored by the Natural Resources Defense Council, a Washington-based environmental group, and the Soviet Academy of Sciences, which operates under the sponsorship of the Soviet government. Both the NRDC and Moscow favor a comprehensive ban on nuclear testing.

The Reagan administration, however, says it believes such a move is premature, arguing that testing is needed to ensure safe and reliable atomic weapons. It also claims it doesn't have the means to catch the Soviets if they decided to cheat.

The two governments are negotiating over verification techniques for two less-stringent test-ban treaties, signed in the 1970s but still unratified, which set a threshold of 150 kilotons on the underground explosions. Experiments with detection technologies different from those being used here are being set up in the Soviet Union and the United States. US officials contend that these government-to-government efforts are the way to proceed toward a comprehensive ban.

Yet scientists like Thomas Cochran of the NRDC, who is helping spearhead the independent initiative, argue that the seismic tests here, together with those conducted in the Soviet Union, will provide crucial information on verification when the two sides finally do get around to a ban.

But there's also a people-to-people side of the event.

``It's creating a lot of talk,'' says a waitress in Jack and Kitty's Egg Chalet, a restaurant in Big Pine, a town at the foot of the snow-corniced Sierra Nevada where some of the Soviets are staying.

Indeed, there is almost as much stir over the Russians as that over fishing season, which opens Saturday. One woman drove 15 miles down from Bishop to deliver the Soviets fresh flowers and honey wheat bread. Local kids come over to play ball in the evening. A resident dropped by with his pictures of Death Valley to show them.

``Outside of all the phone calls, it's fun having them,'' says Catherine Hall, manager of the Bristlecone Manor Hotel, where several are staying.

The Soviet team arrived in the US April 6 bearing more than a ton of seismic equipment and a healthy supply of Russian black bread, sardines, and their own samovar. Their setup on federal land here near Deep Springs - a moonscape made up of a tiny college and two ranches - consists of two trailers, a satellite dish, and seismic sensors buried deep in the granite bedrock.

The equipment is sensitive enough to detect quivers in the earth made by a low-flying aircraft. This happened one day, and the Soviets jokingly said it was an American spy plane. Two other seismic listening posts, with only US sensors, have been installed in Nevada.

In recent days the Soviet scientists have been recording earthquakes and mining explosions. Today and Saturday their mechanical ears will be trained to detect three chemical explosions of 15, 10, and 5 tons each that will be set off beneath the Nevada desert by US scientists.

The explosions are intended to help the researchers understand the geology of the area and how many seismic stations would be needed to cover the Nevada test site. They will also be looking to differentiate between earthquake signals and those from explosions - a key concern about seismic technology in verification. The scientists believe the experiments will prove that seismographs can detect relatively small nuclear tests even if the tests are conducted in a way that muffles their shock waves, such as in a cavern.

``If the Soviet Union were able to put three or four stations in the US, or three or four international ones were put in, then any nuclear explosion with a yield of one kiloton would be possible to register,'' Mr. Negrebetsky says.

The Soviet team is a diverse group of construction specialists, seismologists, and computer experts. It includes one who has a penchant for driving American cars fast (he has an international driver's license), another who likes Chubby Checkers and Elvis Presley music, and a third who is a sailing buff.

The scientists have spent some of their spare time watching TV, playing cards, and visiting that most materialistic and hedonistic of American places, the Nevada gambling casino. ``We broke even,'' says Nikolai Yukhnin, the official leader - and unofficial humorist - of the team.

The visitors have been taken with American cars, American technology, the amount of fresh vegetables in stores - but mostly the ``magnanimity'' of the people.

``It is surprising - the politeness of all Americans,'' Mr. Yukhnin says. Yet they also have a few qualms with capitalism. ``People here are very occupied with business,'' says Negrebetsky.

Which, of course, is one of the benefits of exchanges. Or as seismologist Nikolai Trapeznikov puts it: ``It is better to see a place once than to hear about it 100 times.''