Several volcanic fissures reactivated and a new one opened in Puna, Hawaii, on May 17 after an explosive eruption at the summit of the Kilauea volcano, the USGS said.Hawaii County Civil Defense Agency warned residents in the East Rift Zone of Kilauea to be mindful of volcanic gas, which it said was especially dangerous for elderly people, children and those with respiratory issues.The USGS said it was not yet possible to tell if the fissures would become long-term active vents or would remain active for a period of time before becoming inactive.These livestreamed videos show volcanic activity at fissures 17, 18 and 20 in lower Puna. Credit: Honolulu Civil Beat via Storyful