Can debris for the Tohoku earthquake and tsunami be used to create new land?
May 15, 2012 8:32 PM   Subscribe

Could rubble and debris from the Great Eastern Japan earthquake be 'reclaimed' to make useable land?

The earthquake and tsunami created an estimated 24–25 million tons of rubble and debris in Japan. Could this rubble be reclaimed to create land that is able to be used for housing or other purposes?
Bonus question: If this is possible, and a new island was created, what would the dimensions of this new land be?
posted by sconbie to Science & Nature (7 answers total)
They did this with Chicago. Here and here. Some of the debris was from the great Chicago fire.
posted by gjc at 9:00 PM on May 15, 2012

Kansai International Airport is built off of the coast of Osaka on a 4km x 2.5km manmade island. According wikipedia, they used 21 million cubic meters of landfill. Who knows if this is accurate but the source says 1 cubic meter of soil weighs 3533.56 pounds. Google says that (3,533.56 * 21,000,000,000) in tons yields ~37 million tons.

So in short you could definitely gain some some non-trivia land especially when you consider that the airport example is an island off the cost whereas this debris could be used to extend land at the shoreline. You'd also have to consider that heavier, denser materials would obviously not create as much new future land as something that was lighter.
posted by mmascolino at 9:13 PM on May 15, 2012

They did this in San Francisco; the Marina District was created from fill, partially including rubble from the 1905 earthquake. Soil liquefaction because of this fill construction was a large reason the district suffered so much damage in the 1989 Loma Prieta quake.

So Japan would likely be a little more circumspect; I'm sure the technology of earthworks has advanced in the intervening years, of course.
posted by Homeboy Trouble at 9:24 PM on May 15, 2012

Best answer: Sure, they could use the rubble to make new land -- this could be problematic, though, which I'll detail below. They could process the rubble (lots of rocks and building materials, I'm assuming) by crushing it up with machines. They could also use it to create other building materials like concrete, roads, etc.

City planners use in-fill to create a lot of usable land -- the problem is the type of in-fill that is used. Using fill to create land in Chicago (or Boston or lots of other cities) may work just fine, but when you take some rocks or rubble and make some land in a location that is prone to earthquakes (such as Japan), well, you can end up with disaster. If engineers use fill that is made of lots of unconsolidated sediments (like loose sand, small rocks, dirt, etc.), then the ground could very well be subject to liquefaction when an earthquake occurs. Liquefaction generally occurs when you have two things present: unconsolidated sediment and groundwater. When the earth shakes due to an earthquake, the water in the unconsolidated sediment will cause the ground to become unable to support anything above it (like buildings) -- it acts almost like quicksand. If you've been to the beach, you may have noticed that as you get closer to the water, your feet sometimes get pulled down into the sand as the waves swash back out to the sea. This is somewhat similar with liquefaction: the ground shakes, which consequently shakes the groundwater (it flows like the swashing of a wave), and the land can no longer support structures at the surface (your feet). This is exactly what occurred with the Loma Prieta earthquake in San Francisco in 1989. Engineers made new land by filling in parts of the San Fran area (the eastern side in particular) over the past 100 years -- they filled in marshes and added new land along the shoreline of the bay. This fill was largely unconsolidated, sandy sediment. This spelled complete destruction for so many structures in the city.

So, getting back to Japan -- yes, they could use the rubble to make new land. I guess the question is whether it would be pragmatic to do so, unless, of course, they had enough rubble to compress into strong enough land. This is exactly what they had to do with the Kansai Airport in Japan. Engineers used sediment to create land for the airport (just a small island) and they had to take into consideration that the area was prone to earthquakes (and, thus, liquefaction). For this reason, they greatly compressed the land they were creating in order to make it super dense. In fact, this compression by adding more and more material to it actually caused the island to sink from its own weight. It's still sinking today. This would be the flip-side of liquefaction, I suppose. However, the island and its structures have survived many earthquakes, so chalk one up for the engineers!

(I just taught a Geology course where we talked about this.)
posted by paperclip2000 at 9:33 PM on May 15, 2012 [3 favorites]

They can't anymore. They've already gotten rid of it, haven't they?
posted by Chocolate Pickle at 9:51 PM on May 15, 2012

Best answer: They're having a very hard time getting rid of it because even after testing to make sure it fits under the guidelines of various prefectures, many prefectures are refusing to accept any debris. Even if the debris were found to be totally safe, the mood in Japan is such that any land publicly known to have been reclaimed using rubble from the earthquake and tsunami would likely be shunned. That likelihood would probably prevent any project along those lines. If you offered a plot of land created from that rubble, there's a good chance that, no matter how cheap you made, no one would buy.

Another thing to factor in is how much damage the reclaimed land in Chiba along Tokyo Bay sustained in the quake. Our house was mostly fine, even though the strength of the quake (on the Japanese scale) was a lower five. Just a couple miles south, where the reclaimed land begins, there was massive damage due to liquefaction of the reclaimed land. Sewer pipes, manholes, whole assemblies rose up out of the ground, in some places upwards of three or four feet. Kaihin Makuhari Station, on the Keiyo train line, physically rose two to three feet, causing huge problems with the tracks. Closer to Tokyo, near Disneyland, there were reports of objects that sank into the soil, including bicycles and even a small car, that were then trapped when the soil regained solidity. People in Urayasu, some 150 odd kilometers (a guess) from the epicenter, were without running water (toilets, showers, eveything) for over a month.

From a "could it be done?" standpoint, the answer is yes. Look at Kansai Airport, or even Hong Kong, where they've done massive reclaiming projects. If the question is "will it be done?" I'd have to say the answer would be not likely, not without corruption, payoffs, and outright lies to potential purchasers.
posted by Ghidorah at 2:16 AM on May 16, 2012 [3 favorites]

A big chunk of manhattan island is made from garbage. I think its indonesia that is making new land buy burning their garbage and using the ash to make new land.
posted by majortom1981 at 9:40 AM on May 16, 2012

« Older Sleeping suggestions for a mattress-less house   |   I'm moving to Santiago, Chile! What now? Newer »
This thread is closed to new comments.