(KHNL) Mauna Loa's massive eruptions and rivers of lava could pose a danger to much of Hawaii island , depending on where it comes pouring out.
One of the biggest area of concern is on the volcano's southwest rift zone, where people have built homes and where lava could erupt right from the ground.
"When there is an eruption of Mauna Loa - that means a vent can break out underneath your house" says USGS Geologist Frank Trusdell.
Underneath Oscar Harnik's house, lava flows formed caves and archways. Beautiful creations now, but also reminders of a destructive past.
Oscar and others who live in Hawaiian Ocean View Estates know the next eruption may come with little warning. Many in this quiet community without power and phones may not get even that.
"If there's an eruption...they'll sound the sirens , they'll sound the siren and we'll never hear them. " states Oscar Harnik.
Many also know this lava rock landscape is at the mercy of Mauna Loa.
"History repeats itself...the volcano will inundate this place."
But this is not the only place where lava flows are visible reminders of this powerful force of nature. Just outside of Hilo is another, where lava from the 1984 eruption stopped just four miles from town.
Michelle Icari witnessed that last eruption. Her quiet Kaumana house is not far from that flow and fears over another eruption are also close at hand.
"I'm in that danger zone. An eruption is a big concern. I want to know when is it going to happen?" says Icari.
Scientists can't say when but they do say - be prepared , watch for warning signs and be ready to leave a danger area --- as difficult as that may be.
"I have evacuated thousands of people over the years , but a volcano evacuation is different. There is a tremendous emotional difference when you evacuate for a volcano because you are going to change a lifestyle of people forever. When you are telling them to leave , you know they are never coming back" states Mayor Harry Kim of Hawaii island.
But this risk is just part of the hazard of living with Mauna Loa - Hawaii's looming danger.
"This is the most active shield volcano on the face of the earth....the face of the earth."
Volcano footage copyright Jay Harada, available from volcanovideo.com