Imagine opening your morning paper to find that "evildoers" had landed on an American shoreline, left four people dead, burned homes and churches, ignited forest fires and unleashed the nation's worst single source of air pollution.

All those calamities have been visited on the southeastern coast of the Big Island of Hawaii, not by terrorists, but by a continuing eruption of the Kilauea volcano. Now in its 20th year, it is the longest sustained eruption since Westerners began keeping track more than 200 years ago.

The latest outburst began May 12, Mother's Day, when a 2,000-degree river of lava began oozing from the Pu'u 'O'o crater on Kilauea's southeast flank and pouring downhill toward the sea. When it crossed the severed Chain of Craters highway, it gave tourists unusually easy access. Daily crowds jumped from a few hundred people to nearly 4,500 who arrive by day and night.

"What is so seemingly black and lifeless in the light of day, all of a sudden comes alive after dark," says Mardi Lane, a Hawaii Volcanoes National Park ranger.

Visitors park along the highway, then walk up to two miles to see the glowing red lava enter the Pacific. It dribbles over a seaside cliff like candle wax and into the surf. The heat vaporizes the seawater with a roar, creating dangerous steam clouds laden with hydrochloric acid and volcanic glass.

The park has mobilized everyone from rangers to mule wranglers to ride herd on the crowds 12 hours a day. "Our mandate is to provide safe access to volcanic activity," Lane says. "It makes sense to drop what we're doing to staff this spectacle."

But they can't watch everyone. Two who ventured out on the new lava at night disappeared into the sea - one in a fall, the other when the fragile lava shelf collapsed. Two other visitors were found dead, their lungs seared by the steam.

The "Mother's Day flow" is only the latest action in an eruption that began Jan. 3, 1983. So far, it has destroyed the Hawaii Volcanoes National Park's Waha'ula Visitor Center, the Kamoamoa Campground, petroglyphs and a rock-walled temple site left by ancient Hawaiians.

Just outside the park's boundary, creeping lava flows have incinerated and buried 181 homes in Kalapana Village, burned or surrounded homes in the Royal Gardens subdivision, and destroyed a church and a community center.

Lava has swallowed eight miles of coastal highway and burned power and telephone lines. Thousands of acres of rain forest are gone, along with many rare island birds, bats and insects. Miles of palm-shaded, black-sand beaches have been buried by molten rock.

Scientists say this section of the coast has not seen such lava flows in a thousand years. Every day, 400,000 to 800,000 cubic yards of liquid rock bubble up from the interior, enough to pave Washington, D.C., in five days. Pouring over 30-foot cliffs and into the ocean, it has expanded the Big Island by more than 560 acres.

Every day, the U.S. Geological Survey says, the eruption pumps 2,500 tons of sulfur dioxide and plenty of hydrogen chloride and airborne glass particles into the air, making the volcano twice as bad as the nation's worst single source of industrial pollution.

But it is a gusher of opportunity for geologists studying "hot spot" geology. Most believe Hawaii's volcanoes stand above a rising plume of heat that originates in instabilities at the base of Earth's mantle, about 1,800 miles beneath the ocean floor. This hot spot has been leaving its mark on the planet since the age of dinosaurs.

"We know - we think - it's been operating for at least 80 million years," says Kevin T.M. Johnson, a marine geologist at the Bishop Museum, Hawaii's State Museum for Natural and Cultural History.

Johnson says the chain of volcanic islands and underwater mountains, or "seamounts," that stretches from Hawaii to the northeast coast of Russia was created as a slab of Earth's rocky crust, called the Pacific Plate, drifted over the mostly stationary hot spot. Imagine a cookie sheet passing over a hot flame, creating a chain of volcanic "bubbles."

There are similar hot spots elsewhere in the Pacific and under some continents. Yellowstone National Park in Wyoming sits atop a hot spot whose ancient history geologists can trace in a chain of rock features across southern Idaho.

Volcanic eruptions on Hawaii have been building the Big Island's height from the ocean floor for 1.5 million to 2 million years, says University of Hawaii geologist Ken Hon. In that time Mauna Kea, Mauna Loa, Kilauea and two other volcanoes on the island have built it to a towering 30,000 feet as measured from the ocean floor. "They grow amazingly fast," Hon says. By mass, it is the world's largest mountain, and Earth's crust sags beneath it.

Moving north and west from Hawaii, the islands in the chain get progressively older and smaller. Each in its turn, Kauai, Oahu, Maui and the other islands were dragged off the hot spot by the northwestward movement of the Pacific Plate. One by one, their volcanoes went silent and, struck by landslides, collapses and erosion, they began to fall apart.

"Shoddy workmanship," Hon says. The islands are built on "pillow" basalts that emerge into deep ocean water and harden. "It's not like what we would think of as solid rocks. It's watermelons and ball bearings on the base of these islands."

Beyond the islands lies a string of coral atolls that grew up around still-older volcanoes, now vanished below the waves.

Farther up the chain, Midway Island still peeks above the waves. But beyond that, there is only the Emperor Seamounts. This string of undersea mountains marches northward and vanishes into the Kuril Trench, where the Pacific Plate dives beneath Russia's Kamchatka Peninsula.

Magnetic and chemical analyses have confirmed the common history of the entire chain, Hon says.

But even as tourists snap souvenir photos of the glowing lava spilling from Kilauea's Pu'u 'O'o vent, the old hot spot beneath their feet is giving birth to the next island in the chain.

Twenty-five miles southeast of Kilauea, at the bottom of the Pacific, Hawaii's youngest volcano, Lo'ihi, is also erupting. Discovered barely 25 years ago, the eruption has been piling up lava on the sea floor for 100,000 to 200,000 years, geologists say. Lo'ihi is nearly two miles tall, but its summit is still 3,300 feet below the ocean's surface.

So, that romantic getaway to a palm-shaded beach on Lo'ihi will have to wait. "We estimate it will be anywhere from 10,000 to 50,000 years before it reaches sea level," Johnson says. "That's one to five times the length of civilization so far. We'll be lucky if humanity still exists."

For updates on the eruption, go to http://hvo.wr.usgs.gov/ kilauea/update.