ONE OF THE TOPICS that Lewis Carroll's Walrus never got around to discussing with the Oysters was "why the sea is boiling hot." The Arctic is dominated by an icy sea, and British photojournalist John Dyson offers a number of arch justifications for calling it hot. For one, the region's profoundly cold air feels hot. But most important, the Arctic is a hot prospect for oil and gas production.

Dyson defines the true Arctic as a far-north territory of intense, perdurable cold, where the ground is always frozen and trees cannot survive. This formulation excludes northern Scandinavia and Russia, whose cold temperatures lack the stamina required for admission to Dyson's pantheon of frigidity, but encompasses Alaska, northern Canada and Greenland.

Out of a fastness that can be drained of color and devoid of perspective for miles on end, Dyson educes a treasure-trove of amazing polar facts. Here are a few of the marvels. Notwithstanding its snow and ice, the Arctic is officially a desert: in few spots does precipitation exceed 10 inches a year. The name "Greeland" is a hoax perpetrated by Erik the Red as settler bait. The world's longitudinal lines converge on the Arctic, where distances are suitably deceptive: "Point Barrow, the most northerly point of the USA, is as close to Britain as to Washington DC." "The musk ox is particularly sensitive to disturbance because it has sweat glands only in its feet and can quickly become overheated."

It was the 1968 discovery of oil at Alaska's Prudhoe Bay that quickened interest in exploring the rest of the Arctic. So far the results have been disappointing, but there is good reason to think that certain offshore formations are rich in oil and gas. Offshore Arctic drilling is hazardous, fearfully expensive and ingenious. At summer's end one company artificially augments shorefast ice so that drilling can begin before Nature would confer enough thickness to support a rig. A nice technique employed in shallow water is to cut through winter ice and dump enough gravel to form an island, which supports the rig when the ice melts.

Dyson accepts all of this activity placidly. The Artic is vast, he reasons, and once the exploration stage is passed, extraction can be confined to a small site. Yet his speculations on Arctic accidents are harrowing. Consider, for instance, an oil spill that is trapped beneath the ice and carried along by massive floes torn off from the polar ice pack. The oil's emergence would be impossible to predict or control.

Dyson takes a complex attitude toward the Eskimos, who tend to be deracinated, alcoholic, dependent on welfare and bored. He refuses to patronize or sentimentalize them. He dismisses their claim to be the world's best conservationists as "patent nonsense. In former days Eskimos killed everything they could lay their hands on, and were conservationists only because their primitive weapons did not allow them to make a significant dent in wildlife populations . . . Today, they wish to have the same freedom to hunt with rifle, snow-machine, and fast motorboat as they enjoyed in the days of spear, dog-team and kayak."

Yet he voices outrage over white insensitivity to Eskimo traditions and needs. Of the government's decision to cram hundreds of Greenland Eskimos into five-story apartment buildings, he remarks, "Nobody came to say that kitchen cabinets were not for keeping chickens, or the bath for flensing seals." At times he lets his irascibility get the better of him, as when he declares that the "ultimate aim of the Alaska Native Claims Settlement Act [which extinguished aboriginal land claims in return for a cash and land transfer] was the total assimilation of the native people." I won't argue the point that assimilation may be the Act's ultimate result, but its aim was to remove the claims as a barrier to construction of the Alaska pipeline.

Altogether, Dyson's views have a disturbing tendency to vacillate. It is impossible to tell, for example, whether he considers the environmentalists' Alaska parks bill, which would preserve some 120 million acres, to be excessive or just right. The best parts of his book -- and they are excellent -- consist of unadulterated reporting. In an interview with a middle-aged Canadian Eskimo, Dyson elicited a comment that sums up the native peoples' plight better than all the pages of his own analysis: "'[Our kids are] caught in the middle, not good enough for White men but not tough enough to live on the land. We Eskimos aren't lazy -- just screwed up.