ABC News talked to a University of Cincinnati geosciences professor about the seventh eruption of an Icelandic volcano that prompted new evacuations and closures in a coastal hamlet.

Residents in Grindavik evacuated the town again Wednesday after a nearly two-mile-long fissure opened up, spewing lava. The lava threatened a world famous site called the Blue Lagoon.

UC College of Arts and Sciences Professor Thomas Algeo told ABC News that the eruption comes from a rift activity volcano in which deep fissures are pulled apart through the Mid-Atlantic Ridge. This differs from conical volcanoes that can have explosive eruptions.

Algeo said the eruption is far less dangerous than other types because it creates slower-moving basaltic flows of lava.

"It's a style of volcanic activity that is effusive, slow flowing, not violently eruptive, like would be the case with a subduction zone volcanic system" Algeo told ABC News.

The eruption is the seventh there in the past year after sitting dormant for more than 800 years. 

Read the ABC News story.

Featured image at top: Visitors admire a volcanic eruption outside Grindavik, Iceland, in August. Officials say the volcano erupted for the seventh time this week. Photo/Maria Semenaka