Japan - Media and Plates and Earthquakes

On my flight back to New Zealand from Narita, sat next to a Japanese gentleman who was reading a Japanese newspaper. Apparently the Asahi Shimburn International version. Mostly Japanese characters as far as I could make out, but it did have quite a bit of stuff about Fukishima and the earthquake...

It has this graphic of one of the Fukishima powerstations. It's a very good graphic because it's simple. And it shows the whole thing's operation. The reactor itself is the closed cylinder within the containment vessel on the left of the graphic. It shows the fuel rods at the bottom. It also shows the cold water flowing in, getting hot, turning to steam, and then being piped to the turbine wheel. You can see that this turbine while then turns the generator, which creates electricity, which is then sent on pylon cables for use. The steam then passes for further cooling (condensation back to water), and you can see a further network of pipes at the bottom of the graphic. These will almost certainly be bringing cold seawater in to do this cooling, and the warm seawater is then discharged back into the sea. The water circulating back through the reactor - going in the bottom cold - will be fresh water. The accident at Fukishima primarily relates to the circulating freshwater escaping - as steam - and being released. Because that water passes through the reactor it will be exposed to radioactive fission materials (such as Caesium 137 and Iodine 131), and can be contaminated with those materials which pose a danger to health if the water is released into the environment. Some of that ahs happened. (see blog postings "What the F is happening at Fukishima for more")

Anyway, what was interesting was the way the newspaper also had some neat little graphics about the earthquake and about the tectonic plate movements that caused the quake. The bottom image is a graphic depiction of the fact that the tectonic plate (part of the earth's crust) upon which sit the islands of Japan (including the main island of Honshu, the northern island of Hokkaido etc, shifted or scraped across the Pacific plate, which slid beneath.

What was also interesting was the way the computer map of my plane trip showed this fault, or place where the plates are interacting. I took this photo which shows the plane I was in heading out of Tokyo. The dark chasm to the right is the Pacific faultline which was the epicentre of the magnitude 9.0 quake which hit Japan. It is interesting because all these images and signs suggest that the Japanese people are generally given a good understanding of what has caused the earthquake.

I found these next two images on Google. This one gives the names of the various plates, or sections of the earth's crust, in the vicinity of the earthquake.

And this is a great picture which further illustrates what is happening. The Pacific plate is moving westward and being subducted beneath the northern part of Japan, which is on the Okhotsk Plate. The obvious trench to the east and the mountains and volcanoes of the Japanese islands indicate that this is a place where plates converge. The Southern Alps in the South Island are also caused by upthrusts from plates converging. The epicenter of Japan's earthquake is on the offshore shelf, and not in the trench, as shown in this graphic. Earthquakes are caused by breaking and movement of rocks along the faultline where the two plates collide and slide. The earthquake moved Honshu 2.4 m (7.9 ft) east.