HAWAII NATIONAL PARK, Hawaii >> A geologist with the U.S. Geological Survey’s Hawaiian Volcano Observatory will be giving a free presentation on the Kilauea volcano’s explosive past. 

Don Swanson’s presentation at 7 p.m. Thursday at the University of Hawaii’s Hilo campus will focus on recent research showing that Kilauea has experienced long periods of explosive eruptions over the past 2,500 years. 

The USGS says its gentle lava flows and infrequent high lava fountains over the past two centuries has rarely been hazardous to people but Swanson’s study with geologists from the Smithsonian Institution and the University of Hawaii reveals Kilauea is not always so benign.

He says volcanic activity has alternated between periods of dominantly effusive and dominantly explosive eruptions. However, he notes there’s no indication the next explosive period will be anytime soon.