Lava Tubes (Volcano: to rent, house, buying) - Big Island - Hawaii (HI) -The Island of Hawaii - City-Data Forum

MyrrMade · 08-10-2012, 02:54 PM

I read--from OpenD, I think---to be alert for lava tubes when looking at lots/land. With the rampant foilage covering most lots, how would you know it was under there somewhere? Are there ways of detecting lava tubes? It would be kinda cool to have one, but obviously presents problems for building.

OpenD · 08-10-2012, 04:07 PM

Well, you can't really, unless part of one has collapsed. And as Hotzcatz mentioned, sometimes the way you find one is to have the land collapse under your bulldozer.

But you can look around for holes in the ground, openings, rolling folds in the surface that give you a sense there is something underneath. And really look around, for potential issues. A friend asked me to walk around a lot he was considering and I noticed at least a half dozen huge old tree trunks that had fallen... there had been a huge blow a half century ago that knocked down a lot of old growth trees in the area... and been logged out, but the trunks remained. And I knew from experience it would be a lot of work (read: expensive) to get them out. So I asked him what he planned to do about them, and his reply was: "What tree trunks?"

Another guy was excited about a place that looked promising in the satellite photos, like a gently rippling grassy field... ideal for building, right? i took a look on his behalf, and found an extremely rough, uneven, rocky plot which was covered with 7' tall wild ginger, a highly invasive weed. I climbed up on a hill on an adjoining lot and looked down, and sure enough, the tops of those wild gingers looked like a gently rippling grassy field at a distance.

As several of us have said in various threads here, it's foolhardy to buy land in Hawai'i that you've not inspected closely. There are just too many variables involved.

CyberCity · 08-10-2012, 09:08 PM

Yes, OpenD is so right to recommend not buying sight-unseen! And there are other considerations to be on the lookout for besides lava tubes, especially if you plan on building a home. Some folks hire a soil engineering company to do report prior to building and installing a septic system.

HiloDiver · 08-10-2012, 09:29 PM

Quote:

Originally Posted by opend

as several of us have said in various threads here, it's foolhardy to buy land anywhere that you've not inspected closely. There are just too many variables involved.

ftfy...

hotzcatz · 08-11-2012, 03:43 AM

And should the ginger have actually been rolling grassland, it may have actually been a flood plain in disguise. Frequently, if you find a big grassy expanse in a forest (at least around here) it might be because it floods often enough to wash away the young trees. Although sometimes the grass is from cows, then it's good. Although, another way to find lava tubes is to let the cows wander around until they fall in one. Someone had that happen and it took a couple days to get the cow out. I think it was okay but it was a huge hassle.

oregonwoodsmoke · 08-11-2012, 12:22 PM

If the property is big enough and you know it is there, it might be fun to have a lava tube if you had one big enough to get down into and walk around. Your own personal cave.

I can't think of any way you'd know the property had one unless it was broken open. There is probably specialized equipment that measures density of soil that would detect them, but that wouldn't be for homeowners.

There is always the thought that it was a lava highway in the past and maybe the lava would flow down it again. That's a little scary.

OpenD · 08-11-2012, 01:32 PM

Quote:

Originally Posted by oregonwoodsmoke

There is always the thought that it was a lava highway in the past and maybe the lava would flow down it again. That's a little scary.

Well, yeah, it was ALL lava originally, but for most of the island the last lava flows were thousands of years ago. Not all of it, of course. The last house burned up by lava was only a few months ago, but the risk zones are pretty well delineated. The owner of that house had built on fresh lava, so he knew the risk he was taking.

MyrrMade · 08-11-2012, 02:06 PM

A cow fell in!! Well, that's one way to find a lava tube. Poor bovine!

You are all preaching to the proverbial choir here, regarding buying land sight unseen. I would NEVER consider that. Just asking for advice on what to look for when I'm there in person this winter. And I would take the sound advice to rent for long as possible in the area considered. I do have to work here on the mainland half the year for as long as the limbs hold out. But someday hope to retire over there.

So much good advice here. Thanks OpenD and Hotz and all of you. I read daily, and soak it all up!

In my area, it's the aquifer. 2 lots up from mine, tens of thousands have been spent drilling dry wells.

hotzcatz · 08-12-2012, 02:19 PM

The Kaumana cave system is pretty well mapped out and a lot of it goes under several of the big Puna subdivisions. If you get a copy of that cave system overlaid with a map of the subs you'll have an idea if one of the cave branches might be below the property you were interested in. A friend of mine from Alaska is hoping to buy a lot that has a cave under it since she wants to explore in the cave. Not exactly my cup of tea, but she's all gung ho about it.

terracore · 08-12-2012, 03:38 PM

Quote:

Originally Posted by hotzcatz

The Kaumana cave system is pretty well mapped out and a lot of it goes under several of the big Puna subdivisions. If you get a copy of that cave system overlaid with a map of the subs you'll have an idea if one of the cave branches might be below the property you were interested in. A friend of mine from Alaska is hoping to buy a lot that has a cave under it since she wants to explore in the cave. Not exactly my cup of tea, but she's all gung ho about it.

A lot of properties have lava tubes. Some people have had their lots for decades and never realized that it came with a tube entrance (usually in the form of a puka (hole)). Although its possible that the hole opening happened suddenly. We have a property near Volcano with a small tube but looking at the geology of the lot its probably part of something bigger. Pukas, especially smaller ones are usually covered by vegetation and are easily missed. Our other lot has a puka that has been filled in with large lava rocks and cinder. We've decided to escavate it and if we find a cave opening, great. If not it will be a koi pond. Either way it's a neat feature.

A different property that we looked at in Orchidland had a HUGE puka. It was as big as the house. It had been there a long time and had old growth trees coming out of it. It was beautiful. And it had a lava tube entrance on either side big enough to drive a bus through. There was no safe way down to the bottom of the puka since I didn't bring the extension ladder so I didn't get a chance to poke my head into it. Unfortunately the buyer accepted another offer though in the end it was a blessing since we later learned the house had too many unpermitted additions to qualify for a mortgage.