pbr One of the world's most active volcanoes has erupted in a spectacular fashion.br ppbr Scientists say a new vent had opened at the Pu'u O'o crater in Hawaii which caused lava to spray up to 65 ft high into the air on Sunday.br ppbr The Hawaiian Volcano Observatory said the fissure eruption was spotted shortly after the floor at the Pu'u O'o collapsed on Saturday afternoon.br ppbr The activity has prompted the observatory to update the eruption watch to a warning, meaning a "hazardous eruption is imminent, underway, or suspected."br ppbr It occurred along the middle of Kilauea Volcano's east rift zone.br ppbr Kilauea has been in constant eruption since January 3, 1983.br ppbr Officials said the fissure has expanded to about 535 yards long and scientists are hiking into the remote area to observe the fissure and take readings.