Outdoors : End of Trail in Sight for Explorers : Expedition: Six men, six nations working together to reach place where no man has walked before.

When a killer quake struck San Francisco in October and interrupted the World Series for a week, six men and 36 sled dogs were trekking toward the bottom of the world, scarcely aware of it.

As Eastern Europe exploded in freedom, they trekked on. Noriega’s overthrow was no cause for pause.

All the while that the 49ers and Broncos were making their way from summer’s training camp to the Super Bowl, they were trekking, and when the game is played Jan. 28, they will be without a clue or a care as to its outcome.

They are not indifferent to world events, just isolated and absorbed by their own ordeal.

The 1990 International Trans-Antarctic Expedition is also a world event--six men from six nations, not all ideologically aligned.

There are an American, Will Steger, 43, a veteran Arctic explorer from Ely, Minn.; a Russian, Victor Boyarsky, 37, who navigates and breaks trail; an Englishman, Geoff Somers, 38, who writes introspective letters about the journey; a French physician, Jean-Louis Etienne, 41, who conceived the expedition one night with Steger in a tent near the North Pole; a Japanese, Keizo Funatsu, 31, who knows sled dogs, and a Chinese, Qin Dahe, 38, who spent two previous years in Antarctica doing research.

They set off from Seal Nunataks at the tip of the Antarctic Peninsula July 27. They reached the South Pole on Dec. 11. They spent Christmas on the trail. They hope to reach the coastal Soviet base of Mirnyy on the other side about March 1. Today they were expected to reach the inland Soviet base of Vostok, which marks the end of the 750-mile so-called “Area of Inaccessibility” where no man or dog had walked before.

As of today, they have walked, run and skied about 2,750 of their 4,000-mile journey at elevations as high as 11,500 feet in temperatures as low as minus-45 degrees and winds of 100 m.p.h. They are covering 26 miles or more--a marathon--each day. It has been no cakewalk.

A lead dog--Steger’s favorite--died of exhaustion. Their ancient supply plane broke down, creating a temporary crisis. A blizzard kept them tent-bound for 13 straight days. Several strained their backs. Their faces have been frostbitten, scabbed over, healed and frostbitten again. They struggle with sastrugi. They fall down a lot.

Things may get worse. The world’s record low temperature of 129.3-below was recorded at Vostok in 1983, and the daily temperatures have been dropping. As they descend to Mirnyy, there is greater danger of falling into bottomless crevasses hidden by snow. The coastal winds can blow up to 180 m.p.h.

Direct radio communication has been impossible since a period of sunspot activity started 11 days ago, but the team usually is able to file a daily, one-way, taped report by satellite. Also, Somers has sent letters out at intervals.

Some highlights, low points and crises:

Sept. 30--With the dogs tiring, the pace is dragging. It is decided to airlift 15 dogs out to the Punta Arenas base camp in Chile for a rest, which also will lighten the load in dog food. The remaining dogs pick up the pace from 10 to 15 miles to more than 25 miles a day.

Oct. 20--Tim, a 7-year-old veteran lead dog from Steger’s ’86 North Pole expedition, is played out and dies after riding a sled for several days.

“I’ve never felt this low an an expedition,” Steger said.

Ten of the 15 dogs rejoin the expedition, refreshed and eager.

Thanksgiving Day, Nov. 23--The DC-6 ferrying fuel, dogs and supplies from Punta Arenas is grounded by bad weather and mechanical problems. The fuel is for the Twin Otter ski plane that will be used to drop critical food supplies between the South Pole and Vostok. Without the fuel, it would be foolhardy to continue the expedition.

Dec. 4--The Soviets agree to provide 12 tons of fuel from their existing depots at the Pole.

Dec. 11--After 1,992 miles, the South Pole. The expedition is the first to reach the Pole by dog sled since Norwegian explorer Roald Amundsen on Dec. 14, 1911. Amundsen won a race with British explorer Robert Falcon Scott, who didn’t use dogs. Scott arrived in January of 1912 to find Amundsen’s note. Crushed, he perished with his four companions on the way out, 11 miles from a food cache.

Reflecting on those events, Steger, with 15,000 miles of Arctic experience, said: “It was more difficult than I thought it would be . . . beyond anything I ever thought existed. There were some pretty black moments for me when I could see the desperation of other explorers like Scott.

“Antarctica hasn’t changed in 80 years. We depended on electronic radios and airplanes, but we were in weather situations where it was impossible to use both radios and airplanes. We found ourselves way out on a limb, beyond rescue. In one sense, we did experience the remoteness of Scott and Amundsen.”

Geoff Somers writes: “Our last (day off) was Nov. 27. The one prior to that Oct. 20. By day-off time, our minds and bodies are crying out for a rest, a change, a time when we can sleep an extra hour, a time we can relax, read, write and an opportunity to carry out the many repair tasks that accumulate over the previous days--perhaps a dog harness to repair, a lashing on a sled to renew, a hole in one’s socks to mend.

“The dogs, too--and do not forget these faithful creatures--need a rest. We feed them extra food, let them lounge for a day and they are refreshed and bright again.”

Christmas Day--”Very good weather,” the team announces via satellite. “Merry Christmas . . . Joyeux Noel. “ It is a relatively mild 15-below, so they celebrate with a full day of walking and skiing, logging 25.5 miles. Later, they spend a little time huddled together in one tent with a holiday package of Christmas napkins, small decorations, pistachio nuts and extra rations of brandy.

Dec. 31-- “Bonne annee . . . happy new year!” That’s all.

New Year’s Day--Communication unintelligible.

Jan. 4--Steger reports that since mid-November, when he hurt his back, he has been walking or running rather than skiing alongside the sled and sometimes, because of the quick pace of the dogs, must jump onto the sled to keep up.

“Driving my team of dogs is like driving a race car,” he said.

Also: “Visibility is a problem. It is almost impossible to see through goggles that are constantly fogging or freezing. Without the protection of goggles, however, the face would freeze immediately from the wind coming at the team’s faces. Without visibility, combined with a lack of depth of field, the men can stumble or fall up to 100 times a day.”

Then, there is the sastrugi.

“The fields of sastrugi look just like a frozen ocean,” Steger says.

Somers describes it: “This stuff is snow, carved and sculptured by constant wind into great uncoordinated waves and flutings, every shape and size, a few inches high to four, five or six feet. The snow making these is almost iron hard, icy and unrelenting. The sled, like a small boat on a rough sea, rises and falls over these, up, down . . . left, then right.

“Some of our most frustrating days were traveling through these sastrugi in complete whiteout. Even when standing on them, we could not see them, let alone anticipate their effect on sleds and ourselves, the sled lurching on unseen objects of unknown shape and size, often capsizing and on one occasion pinning me underneath.

“One time I tried to stop the sled falling toward me. It lurched and fell over the other way, flinging me head over heels to the opposite side where I landed in an ignominious heap.

“A day of sastrugi would leave us totally shattered, and it was all one could do to make camp, melt water, cook supper and crawl into bed.”

Sunday, Jan. 14--Steger reports good progress of up to 29 miles a day, despite a low temperature of 29-below and the 11,000-foot elevation approaching Vostok.

“The dogs are doing remarkably well, especially considering the long daily distances and the altitude. The men don’t notice the effects of the high altitude in their daily routine activities--even in the steady 25 miles of skiing. But if they turn too suddenly or run slightly faster than the pace, they can sometimes immediately get out of breath or feel dizzy.”

Tuesday, Jan. 16--Steger: “Victor is doing a very good job leading our team and keeping a straight line.”

At Vostok, the journey is about three-fourths complete. Do the dogs know?

Somers: “Their coats have grown and are in beautiful condition. They have put on weight and look positively chubby! They are up and excited. When we stop for rest, they frolic in the snow, lie on their backs, feet in the air or lie fully stretched on their stomachs and chests to cool down on the snow.

“The pace remains almost constant until the end of the day when, perhaps over the last hour, the pace increases. This is, I’m sure, because it’s nearing feeding time and excitement grows.”

Steger has anticipated what still lies ahead. He says he is not afraid of the cold.

“Our team can handle the weather,” he said. “It is the lack of visibility that will be a major problem. We cannot travel when we cannot see because the terrain will be full of crevasses. We will have to sit in our tents and wait.”

And then they’ll trek on, and on and on.