THE outer continental shelf, a ribbon of seabed off the nation's coasts, encompasses an area four times the size of Alaska and topography almost as varied. The undersea world includes vast plains of mud and sand, bold canyonlands, and an occasional mountain. Yet what may be more interesting is what lies underneath it.
The oil industry sees the continent's submerged edge as one of the last great hopes of finding new sources of energy and rescuing the nation from increased dependence on foreign crude. But environmentalists, worried about oil spills and befouled beaches, want to keep large portions of it from becoming a pincushion for drill bits.
Now the debate over offshore oil drilling is coming to a head.
Fresh from their victory in the US House of Representatives, opponents of offshore oil development are pushing for a drilling moratorium in the Senate, over the objections of an increasingly vocal Bush administration.
If the fight sounds familiar, that's because it is. In six of the past seven years, Congress has passed a one-year moratorium on offshore drilling along much of the nation's coastline in the face of administration attempts to open up more areas to energy development.
This time, however, the battle is different. The moratorium being put forward is more extensive than any in the past. It comes at a time when a full-throated debate over the direction of US energy policy is emerging.
Hoping to capitalize on public outrage over a rash of oil spills, environmentalists and some lawmakers would like to see the United States move away from its dependence on fossil fuels and rely more on conservation and alternative energy sources, such as solar.
But others are trying to stave off what they see as an overreaction to the tragedy in Valdez, Alaska, and convince Congress and the public that oil and gas exploration can be conducted safely.
``The moratorium has taken on a lot more significance,'' says Charles Ebinger of the Center for Strategic and International Studies in Washington, D.C. ``I think we are seeing a fundamental shift toward environmental concerns over energy concerns.''
The ban passed by the House and awaiting action in the Senate would postpone any activity on proposed oil-lease sales off the entire California coast until at least October 1990. It would also put one-year prohibitions on drilling off Florida, six Mid-Atlantic states, and, for the first time, in Alaska's Bristol Bay.
``We've got the attention of the nation because of all the spills,'' says an aide to Sen. Pete Wilson (R) of California, who has vowed to lead the campaign for a ban.
The Bush administration, which had hoped to put up more of a fight in the House, is now trying to rally opposition to the moratorium in the Senate. This week, several top administration officials spoke out on the dangers of limiting energy activity.
Most vociferous was Interior Secretary Manuel Lujan Jr., who told a meeting of Western governors that ``by imposing moratoria, the Congress is saying we should blindly reject even the possibilities before us.''
Ban opponents point out that tankers caused the recent oil spills, not offshore oil rigs, which they contend have environmentally sound records.
To ensure safe oil transport, Mr. Lujan suggests building ``super ports'' in deep waters where ships can unload their cargoes. The oil would then be transported to land by pipeline.
But ban supporters counter that deep-water ports wouldn't work in the rough seas off northern California and the Pacific Northwest. Nor, they argue, would oil and gas from offshore rigs be transported by pipeline. They say local communities wouldn't allow the pipelines to be built, thus resulting in more tanker traffic.
``Oil in a marine environment just doesn't work,'' says Robert Sulnick, executive director of the American Oceans Campaign, an environmental group.
The Interior Department estimates that one-quarter of US gas reserves and one-sixth of all oil reserves remaining to be discovered lie on the outer continental shelf. Opponents of drilling contend the estimated reserves in sensitive areas are too small to warrant the risk of drilling. Oil companies say the nation can't afford to pass up finding out.
``We cannot conserve our way out'' of the current energy situation, says Joe Lastelic of the American Petroleum Institute, which released figures this week showing domestic US oil production for the first six months of the year at its lowest point in 25 years.
If the moratorium passes Congress, as some analysts expect, it will be an important political victory for drilling foes. It would mark the first ban passed in the Bush reign. It could also undermine the authority of a task force appointed last February by the President in hopes of restoring a national consensus on offshore exploration.