Iceland's unique volcano provides an extraordinary glimpse inside the Earth

Twenty miles from Reykjavík, Iceland's capital, scientists, tourists from across the world and locals are flocking to see one of Earth's most stunning shows: a volcanic eruption fountaining lava - at times - reaching nearly 1,000 feet in the air. Since March 19th, Iceland's newest volcano - called Geldingadalir - has been erupting and spewing ultra-hot lava with temperatures over 2,000 degrees Fahrenheit. Scientists say the magma is coming from an unusually deep place in the Earth - and this is their chance to solve the mystery of where magma originates. 

60 Minutes Plus cameras captured the eruption from both above and below. A helicopter flew the team over the bubbling and flowing lava rivers, providing a bird's-eye view of the glowing wound in the earth. The crew trekked to the volcano on foot, where a change in wind direction and elevated poisonous gases from the eruption forced a swift evacuation. Despite the deadly gas emissions, Thordarson said volcanic activity is key to life on Earth.

"Volcanic activity replenishes the atmosphere," Thordarson explained to Doane. "The reason why we have atmosphere and we have something to breathe is because we have volcanoes who put gasses out in the atmosphere."

Thordarson tracks the movement patterns of the volcano's lava flows, so he can predict how and where it will go. He said there's a small chance the eruption could become more violent and "explosive." Scientists from Iceland's Meteorological Office say the eruption continues to be subdued, but they're keeping a close eye on its dynamic, pulsating behavior. 

Thordarson told 60 Minutes Plus that this eruption is similar to one he studied in Hawaii, one that remained volcanically active for 35 years. "There's a 50/50 chance that this will-- this eruption will end tomorrow or it will last for decades, in my opinion," Thordarson said. "I think it is more likely to… keep on going than stopping."

After nearly 800 years of dormancy, the Reykjanes Peninsula received warning of an imminent eruption, when over 50,000 earthquakes shook the region in a matter of weeks. Thordarson explained that "eruptive episodes" can last for hundreds of years. "And then there's a pause that lasts for 500 or 1,000 years or so, but 800 years on average," Thordarson told Doane.

Around 80% of Earth's volcanic eruptions happen underwater, but this new volcanic activity in Iceland can be seen from the streets of Reykjavik and reached by hiking trails. It's that remarkable accessibility of the volcano that lends to its danger. 40 members of the country's national volunteer search and rescue team patrol the site daily to keep visitors safe.

Correspondent Seth Doane speaks with scientists monitoring and racing to understand the volcano, Iceland's search and rescue team, "volcano tourists" and owners of a local farm who say the volcano is on their land.

Watch the story now on 60 Minutes Plus, streaming only on Paramount Plus.