The erupting Nyamulagira (also known as Nyamuragira) volcano reddens the sky on Sunday in the Democratic Republic of the Congo. (See an interactive cutaway of the Nyamulagira volcanic region.)
Nyamulagira, which generally erupts every two years, rumbled to life at 8:06 p.m., spewing lava, smoke, and ash throughout Virunga National Park. The volcano sits within the park, about 25 miles (40 kilometers) north of the city of Goma (map).
The park's communications officer, LuAnne Cadd, first got a phone call about the event from rangers, who'd heard noises like gunshots, she said.
Cadd immediately went outside to take pictures of the nighttime spectacle, which was occurring an estimated 6 to 12 miles (10 to 20 kilometers) west of park headquarters in Rumanbago, she said. (See a park map.)
"What's quite astonishing is how bright it is, how it lights up the sky with a red glow, and the sound. We can hear the dull roar of it, especially at night in our tents," she told National Geographic News via email.
"I'm actually looking at it while I'm talking to you—it's so amazing, just a monstrous fountain" of lava, Cadd said.
"It's mesmerizing and hard to pull your eyes away from it."
Experts say the volcano could continue erupting for weeks and even months, Cadd added.