My wife and I own an 8 acre property near the ocean north of Hilo on the Big Island of Hawaii. The land overlooks what appears to be at least 60 foot high cliffs.
The east side of the Big Island has been hit by large tsunami waves in the past and this worries my wife. I’ve tried to tell her that the tall cliffs would protect the property should another tsunami strike the island, but she’s still concerned.
What would happen if a series of large tsunami waves were to hit these rather solid 60 foot high volcanic rock cliffs?
Depends on the waves. 60-ft cliffs will dissipate a lot of wave energy, and in most cases offer sufficient protection. But there’s no law of physics that says a wave big enough to surmount this cannot exist.
Indeed, the geological record shows evidence of tsunamis with waves much higher than 60 ft. Here’s Wiki on Megatsunamis.
Here’s an interesting video (captions, but no sound) that includes a computer simulation of a “flank collapse” on the southeast coast of the Big Island (where the Kilauea volcano has been building up lots of material). It would produce a wave close to 1000 ft high that would cause massive damage. There is evidence of many such landslide events in the geological history of the Hawaiian Islands.
And there’s the issue of cliff erosion - enough smaller waves might reduce the size of those cliffs.
Not really that worried about Mauna Loa going off. Each year that passes moves the “hot spot” further south away from the property. In fact the area where we have the land hasn’t been covered with lava for over 60,000 years. All the volcanic activity is about 70 miles south of us.
The area where we have the property gets over 120 inches of rain each year. This sounds like a lot to people who haven’t lived on the island, but the fact is that most of it falls at night or in the early morning just before sunrise. And because the land is volcanic, the rain soaks into the ground very quickly. One weekend a few months ago we had almost 15 inches of rain come down, but by the time it stopped there was barely a puddle on the property.
Besides, the rain waters the 300 fruit trees I have growing on the land. Having to pay to irrigate that many trees would put me out of business. The rain also fills the stream that borders the property. We installed a mini hydro electric system in it that gives us all the electricity that we need.
Head is the most important aspect in deciding whether a hydro system is suitable for your property. “Head” means how steep the incline is that the stream on your property is flowing down. Without enough incline you’re just not going to be able to generate enough power to make the investment worth it. A hydro professional should come out to your place and measure it for you.
Before you ask about price, you have to answer the question of whether or not you are already hooked up to the grid in your area. We were not hooked up and the cost of connecting to the local grid (bringing in the poles and wires) turned out to be more costly than the hydro system. We spent around $15,000 for the system we have.
As far as having it pay for itself, it already has in the sense that we didn’t have pay to become part of the grid. Hawaii has some of the highest electricity rates in the USA. A small percent of the island power is generated by geothermal sources, but most is made from burning imported oil. When oil prices go up, up, up, rates follow. Its great to be independent of that. (We’re even independent of the local Water Department. We have a rain catchment system on our roof that fills up a 10,000 gallon tank on the property.)
You are not living directly from the hydro system. The system charges batteries that store the power and this is what is really powering your home. The battery levels need to be maintained and if there is a storm, you’ll have to remove any debris that collects around the intake valves, but maintenance isn’t too difficult.
The nice thing about hydro compared to solar is that its charging the batteries 24/7/365 as opposed to 6 to 10 hours a day at best for a solar system. A guy nearby has a hydro system that charges his electric Nissan Leaf all night and drives it all day for “free”.
For the record, in the 2011 tsunami, there was a restaurant perched atop a cliff in Tomioka, 21 meters (68’) high that got flooded. This was a bit of a worse case scenario as the geography is thought to have cause the water to rise significantly higher than elsewhere.
Yes, but nobody lives at the top. And even if you were at the top when a tsunami that big came, you’d probably still be experiencing a major disaster due to economic ties to the affected areas: Is there enough food left for everyone? Will any of it make it up to your mountain stronghold?
I agree, sounds amazing - but having lived in the middle of grand wilderness before, it’s not for everyone. Enjoy it if it’s your taste, but there’s a reason many people move to the big city.
Yeah, I suppose another part of the calculation is whether your cliff is the end-point of a funnel-shaped bay, or just a straight flat cliff. I assume this aggravates the water level.
Besides, IIRC most of these tsunamis come from fairly remote locations (Alaska? Japan? San Adreas?) so the odds of a megatsunami are even more remote. If Hawaii gets 60 feet I assume LA, Frisco and Tokyo would probably be bigger news… and nobody would hear anything further from most of the South Pacific islands. Plant your end-of-the-world survival gear in a concrete cache 200 feet uphill.
Hey, Mangosteen, old buddy, old pal. We’ve always been real close, right? So, I was just wondering… if me and the missus were to uh… ‘drop by’ sometime for an extended visit… then that would be OK, right? You got lots of food, doncha?
Seriously, your place sounds pretty amazing. I don’t suppose you have any pictures of the property or anything that you’d be comfortable sharing with us, do you? I’m fairly confident that I am not the only person here who is impressed with your setup there.
If your referring to the San Andreas fault, it doesn’t really generate massive tsunamis. It’s a lateral fault which means for the most part land moves sideways. About the only tsunamis that could be generated would be mass movements (landslides into the oceans). But they would be frog farts, in terms of sea water displacement, when compared to a chunk of the Big Island sliding into the Pacific.
In the contiguous US, it’s the northern coast of Northern California, Oregon, and Washington (the COW states) will get hammered when the Cascadia fault ruptures; your’re looking at another Tohoku earthquake, and the same kind of Godzilla force tsunamis hitting the northwest coast of the US. In some cases waves will surge locally almost to 100 feet!
