Volcanic fissures continue to open on Hawaii's big island.

  • Explosive eruptions feared at Kilauea summit
  • Area has been in 1,000-year period of spilling out lava
  • Thousands of people have been evacuated

The 18th fissure opened Sunday morning, prompting more evacuations.

Residents near the newest one say it sounded like explosions were going off as the ground broke open.

And many are now waiting for what experts say could be a major eruption at Kilauea volcano's summit. Hawaii Volcanoes National Park remains closed.

Spectrum Bay News 9's weather experts say the Hawaiian islands were actually formed by volcanoes that started millions of years ago.

Just below the earth's crust is a magma chamber that feeds into the volcanoes, which in turn continues spewing lava, making the islands even bigger.

"There's a hot spot underneath the big island, it's the newest island in the chain, and Kilauea is what forms on top," said Meteorologist Diane Kacmarik.

"They're concerned now … Kilauea has been actually in existence for 100,000 years but it's been in a thousand-year period of just spilling out lava. But if the magma inside that crater drops down below the water table, then there could be some explosive eruptions, and that's what they're concerned about right now.”

Our own Wendy Brown visited the big island about three weeks before the volcano erupted. She says when she visited the volcano park, rangers told her the levels were the highest they'd been in the past 15 years.

"You're actually a mile away and what you're seeing is the lava bubbling up," Brown said. "Normally, you're not able to see that except nighttime when you just see the glow. We actually saw the bubbling up."

Hawaii’s civil defense agency says continued earthquake activity and additional outbreaks in that area are likely. Thousands of people have already been evacuated from their homes.