WATERLOO — Alan Morgan was one of the first people to look into the ferocious mouth of the Icelandic volcano that disrupted air travel last month.

From a small plane with open windows, the University of Waterloo professor took pictures of chunks of rock and ice, each the size of a dining-room table, as they were blown out of the volcano's maw.

He also photographed the Markarfljot river, flooded by melted ice, its flow 1,000 times the speed of the Grand River on a normal day. And also, the unearthly beauty of a huge pillar of steam tinted pink by the setting sun.

All of it was "incredibly powerful, and rather menacing," he said.

Morgan, who is retired, but still teaches introductory geology, has been to Iceland 14 or 15 times in his lifelong study of this planet.

The plane that he and a friend commissioned was the second to fly over the infamous Eyjafjallajokull volcano, three days after the eruption. Lying under a sheet of ice, the volcano's hot lava melted the ice and became a steam-powered explosion.

"This was the first time I'd had an opportunity of approaching a volcano this size," Morgan said.

The volcano grounded 100,000 planes last month and cost the airline industry $2 billion. Planes were unable to fly in case they encountered an ash cloud, which would disable their engines.

In 1982, a British Airways flight to Australia flew through a volcanic ash cloud. All four engines clogged with ash and failed. The pilot was able to restart the engine and land the plane safely.

Morgan showed a sample of Eyjafjallajokull's dark ash, a powdered glass as fine as baby powder, and so high in fluorine that it has poisoned the air, the drinking water and the vegetation on which animals feed.

As disruptive as this volcano was, there's another, much bigger, one nearby named Katla. It's under a thicker ice sheet, so the explosions would be more intense. And if history is any guide, it too will erupt within two years. The two volcanoes are believed to share a deep-seated magma source.

The last three times that Eyjafjallajokull has erupted, Katla has also erupted, Morgan said. The prediction is based on records that have been kept by Icelanders for 1,000 years.

"This is simply a page within a chapter within a book," he said.

If Katla erupts, it would be so large that "it would probably ground all aircraft in the Northern Hemisphere," Morgan said.

"Iceland has the potential of paralyzing the world."

Environmentalists would see a bright side to the eruption, noted Morgan, whose son works for the World Wildlife Fund and is concerned that his father travels by air so much. Air travel is a major culprit in global warming.

If you add up the carbon footprint of all those cancelled flights, says Morgan, the planet was saved from 2.9 million tonnes of carbon dioxide. The volcano only emitted 15,000 tonnes.

He jokes that he may have made a deal with a couple of Icelandic trolls to cause the eruption and keep his son happy.

Morgan, who teaches in the department of earth and environmental sciences, first discovered geology at age eight when he found a fossil in his native Wales. He still has it; a spiral-shaped stone the size of a small egg.

He has been to the Amazon and the Arctic, but Iceland is "one of my favourite countries," he said.

"For a geologist, it's a wonderful country. Geysers, volcanoes, huge ice sheets, thundering waterfalls, raging rivers …"

Morgan has won numerous teaching awards during his career, most recently the 2010 3M National Teaching Fellowship. Morgan is only the third professor at University of Waterloo to have won the award.

He loves the planet and loves to teach about it through personal anecdotes, powerful images and even classroom demonstrations. He'll show how a piece of obsidian can cut through a rope faster than a Swiss army knife, or uses movement through a human chain of students to show how an earthquake works.

Teaching earth sciences, for Morgan, "is a bit of a personal crusade," he said.

He feels it is inadequately taught in schools, and that earth sciences should be taught with equal status to biology, chemistry and physics.

After all, he said: "Planet Earth provides all our needs."