Following the eruption of the Kilauea volcano, residents of Hawaii's Big Island will now have to deal with steam-driven explosions, hazardous volcanic smog and acid rain, the US Geological Survey (USGS) has warned. The USGS's Hawaiian Volcano Observatory on Wednesday warned of possible explosive eruptions in the coming weeks because as the lava continues to sink in a lake inside a Kilauea crater, reports CNN. An influx of groundwater could interact with the lava and create steam explosions, it added. Those forces would emit "ballistic projectiles" - as small as pebbles or weighing up to several tonnes. The USGS also said ash clouds would rise to greater elevations, dispensing ash over wider areas. "At this time, we cannot say with certainty that explosive activity will occur, how large the explosions could be, or how long such explosive activity could continue," an advisory said. Governor David Ige has asked President Donald Trump to issue a disaster declaration for Hawaii as a result of the ongoing earthquakes and volcano eruption, according to a press release. The declaration allows federal funds to begin to flow to state and local efforts in Hawaii. The estimated cost to protect residents over the next 30 days is expected to exceed $2.9 million, according to the governor's office. A brief explosion on Wednesday on a Kilauea crater was the result of falling rocks and not the interaction of lava with the water table, the USGS said. The Kilauea eruption last week created new volcanic vents on the ground miles east of the summit, releasing slow-moving lava and toxic gas into island communities. Officials have warned of dangerous levels of sulphur dioxide gas, CNN reported. Following the eruption on May 1, 1,700 residents were asked to evacuate. At least 36 structures - including 26 residences - have been destroyed since then. Residents were being allowed to check on their properties from 7 a.m. to 6 p.m. each day but must be prepared to leave at a moment's notice, the Hawaii County Civil Defence Agency says.