(CNN) -- Helga Jonsdottir still remembers in vivid detail the day her island home was swallowed by a volcano as she and her family joined others fleeing the molten lava.
"As my boat left the harbor, the fissure opened up, and flames burst into the sky," she recalls.
"The fissure extended into the ocean, and I could see red-hot lava beneath the water."
Jonsdottir was 18 in January 1973 when the Eldfell volcano exploded on Heimaey, a small island 151 kilometers (94 miles) from the Icelandic capital, Reykjavik.