41 Fun Facts About Mount St. Helens

In which US state is Mount St. Helens?

Washington: the volcano stands in the state's southwest, so its nearest big city is actually Portland, Oregon, about 50 miles away.

Because Mount St. Helens erupted on a Sunday, which workers normally found in the blast zone were mostly away?

Loggers: the crews who felled timber all around the volcano were off for the weekend, and officials believe a weekday blast would have killed far more people.

How many people were killed by Mount St. Helens's 1980 eruption?

The 18 May 1980 eruption killed 57 people, most by asphyxiation from hot ash; the bodies of some victims were never found.

By roughly how much did the 1980 eruption lower Mount St. Helens's summit?

About 1,300 feet: the peak fell from 9,677 to 8,363 feet, and the missing top was not blown sky-high but slid away down the mountain's north side.

What shape is the crater left by Mount St. Helens's 1980 eruption?

The blast left a horseshoe-shaped crater about a mile wide, its north side breached where the landslide carried the summit away.

Mount St. Helens's 1980 blast was a 'Plinian' eruption, a type named after a Roman who described which volcano erupting?

Vesuvius: Pliny the Younger's account of the AD 79 eruption that buried Pompeii named the type, and that blast and 1980's share a rating of 5 on the 0-to-8 explosivity index.

Mount St. Helens's 1980 ash column rose 15 miles in 15 minutes, reaching which layer of the atmosphere?

The stratosphere: the eruption roared on for about nine hours, and by 9:45 that morning its ash had turned daylight to darkness in the city of Yakima.

Mount St. Helens's 1980 ash cloud crossed the United States in three days and, within 15, had done what?

Circled the Earth: visible ash fell as far away as the Great Plains, some 900 miles east, while the finest dust stayed aloft and kept going.

What are the volcanic mudflows that raced down the Toutle River from Mount St. Helens in 1980 called?

Lahars are fast mudflows of volcanic debris and meltwater; those on 18 May 1980 choked the Cowlitz and Columbia rivers, cutting the Columbia's shipping channel from 40 feet to 14 feet deep.

Scientists liken the moment Mount St. Helens's north face slid away in 1980 to doing what?

Uncorking a bottle: with the mountainside gone, the pressure inside burst out sideways, levelling 230 square miles of forest at 300 mph or more.

Which 83-year-old lodge owner refused to leave Mount St. Helens and died in the 1980 eruption?

Harry R. Truman: he stayed put with his 16 cats at the Spirit Lake lodge he had run for over 50 years, which now lies under about 150 feet of debris.

What was volcanologist David Johnston's famous final radio call as Mount St. Helens erupted in 1980?

"Vancouver! Vancouver! This is it!": Johnston, 30, was hailing his USGS colleagues, based in the American city of that name, from a post six miles north of the summit on what is now Johnston Ridge.

Photographer Robert Landsburg, caught by Mount St. Helens's ash cloud in 1980, saved his film by shielding it with what?

His own body: he stowed the camera in his backpack and lay on top of it, and when he was found 17 days later the pictures had survived, though another photographer's film nearby was ruined by the heat.

Which US president compared the devastation unfavourably with the surface of the moon?

Jimmy Carter toured the blast zone on 22 May 1980 and said the moon 'looks more like a golf course compared to what's up there'.

Among the major volcanoes of the Cascade Range, Mount St. Helens holds which distinction?

The most active: its frequent past eruptions led three geologists to warn in 1975 that it would erupt again, perhaps within decades, and it did five years later.

Helenite, a green gem made from Mount St. Helens ash, was discovered by accident when salvage workers melted ash with what?

An acetylene torch: crews on salvage work days after the eruption saw the ash around the flame fuse into green glass, a trick soon copied in furnaces to make gems.

Despite its name, Mount St. Helens honours no saint; George Vancouver named it in 1792 after a fellow Briton who was what?

A diplomat: Alleyne FitzHerbert, Baron St Helens, was Britain's ambassador to Spain, the odd one out, since Vancouver named Rainier and Baker after naval officers.

Native American names for Mount St. Helens, such as Louwala-Clough, translate roughly as what?

Smoking mountain: local peoples had watched the peak erupt for generations, and in 1847 the visiting Canadian artist Paul Kane painted it erupting at night.

In the Bridge of the Gods legend, proud suitor Wy'east became which Oregon peak across the Columbia from Mount St. Helens?

Mount Hood: Wy'east is said to hold his head high in pride, and the maiden the two brothers fought over became Mount St. Helens itself, a dazzling white cone until 1980.

What nickname did Mount St. Helens's symmetrical, snow-capped cone earn before 1980?

Fujiyama of America: like Japan's Mount Fuji it was a near-perfect snowy cone, until the 1980 eruption removed the graceful top in a few hours and ended the likeness.

What has drifted across Spirit Lake, below Mount St. Helens, ever since the 1980 eruption?

A raft of dead trees: thousands of trunks felled by the eruption were swept into the lake, and more than 40 years on the survivors still drift from shore to shore with the wind.

What split Mount St. Helens's Crater Glacier into two arms from 2004?

A new lava dome, growing from October 2004, pushed up through the Crater Glacier, splitting it into east and west arms that later crept around the dome and rejoined.

Mount St. Helens is one segment of which great belt of volcanoes?

Mount St. Helens belongs to the Ring of Fire, the chain of volcanoes around the Pacific; it sits in the Cascade Arc, fed by the Juan de Fuca plate subducting beneath North America.

Which Cascade volcano, 34 miles east of Mount St. Helens and some 50 miles from Rainier, is known as its 'brother'?

Adams: the pair are often called sister and brother, though in a Native legend he is a suitor who bows his head in grief for the maiden who became Mount St. Helens.

For roughly how long did Mount St. Helens shake and vent steam before its catastrophic eruption of 18 May 1980?

Two months: small quakes began in mid-March, and within two weeks steam explosions had opened a new crater at the summit, the volcano's first stirrings in 123 years.

Before Mount St. Helens in 1980, where in California was the last eruption in the lower 48 states?

Lassen Peak: the biggest explosion of its 1914–17 eruptions devastated nearby land in May 1915 and rained ash at least 200 miles to the east, and the lower 48 then stayed quiet until 1980.

What nickname did geologists give the long, smooth, rounded lava spine that rose in Mount St. Helens's crater in late 2004?

The whaleback: it was hot but already solid lava, squeezed up from the vent as a smooth-sided shaft more than a quarter of a mile long that kept breaking up as it grew.

Roughly how much of the crater blasted out of Mount St. Helens in 1980 has fresh lava since refilled?

Under a tenth: all the lava that has oozed into the crater since 1980 has put back only 6 or 7 per cent of what a single morning removed.

What did President Reagan and Congress establish around Mount St. Helens in 1982?

A National Volcanic Monument: inside its 110,000 acres the devastated land has been left to recover on its own, which has made it a living laboratory for how nature responds to disaster.

What kind of outing is Monitor Ridge, the standard summer route up Mount St. Helens?

A strenuous day hike: the ten-mile round trip gains about 4,500 feet over boulders and loose ash, but in summer it calls for a permit and stamina rather than ropes or technical skill.

What does the Loowit Trail at Mount St. Helens do?

Circles the entire volcano: the loop runs 32 miles, and hikers must cross the blast zone on its northern side in one push because camping there is banned.

What saved many small animals from Mount St. Helens's 1980 blast, which killed thousands of elk and deer?

They were underground: the blast came on a spring morning with night animals back in their burrows, and ecologists say such survivors, which they call biological legacies, sped the recovery.

What let prairie lupine become the first plant back on Mount St. Helens's barren Pumice Plain?

Nitrogen from the air: bacteria in the little legume's roots capture the nutrient that raw pumice lacks, and the debris each plant traps slowly builds soil for the species that follow.

About how much precipitation falls on Mount St. Helens's upper slopes in an average year?

140 inches: that counts rain and melted snow together, and in a normal winter the snowpack on the higher slopes lies about 16 feet thick, which keeps scientists wary of floods and mudflows.

Which wild cat gives its name to the community nearest Mount St. Helens?

Cougar: the hamlet sits in the Lewis River valley south of the summit, and the real cats, killed off around the volcano in 1980 along with every other large mammal, have since padded back in.

By what official name is State Route 504, the main road to Mount St. Helens, known?

Spirit Lake Memorial Highway: a 1982 state law dedicated the road to those who died in the eruption, and its last stretch, opened in 1997, climbs to an observatory named after one of them, David Johnston.

On the USGS's 2018 list of the most threatening US volcanoes, Mount St. Helens ranks second behind which Hawaiian volcano?

Kilauea: the ranking does not predict which volcano will erupt next but how much harm an eruption could do, and the pair sit among just 18 of 161 volcanoes rated a very high threat.

Mount St. Helens's home state now marks May, the month of the 1980 eruption, as what?

Volcano Awareness Month: the state uses the anniversary of an eruption whose mudflows hit dozens of bridges and about 200 homes to ready residents for the next one.

For about how long did ash from Mount St. Helens close Interstate 90 between Seattle and Spokane in 1980?

About a week: the falling ash cut visibility so badly that roads shut across the state, and crews eventually hauled some 900,000 tons of it off highways and airports.

By roughly how much did the 1980 landslide raise the surface of Spirit Lake, below Mount St. Helens?

About 200 feet: so much rock poured into the basin that the lake bed itself rose nearly 300 feet, and engineers later bored a tunnel 1.5 miles long to keep the dammed lake from bursting out.

Mount St. Helens's 1980 eruption was heard hundreds of miles away in Canada; what did Portland, about 50 miles off, hear?

No sound at all: layers of warmer air high in the atmosphere bent the sound waves back to earth far away, leaving a 'quiet zone' around the volcano, though people in Montana heard the eruption.