We will try to compare Chikyu’s dimensions by using familiar items or landmarks:
Length: 210 m is about equal to 8 Bullet train cars or as long as 8 tennis courts.

The tall blue derrick is more than 130 m from the bottom of Chikyu, just as tall as the Great Pyramid of Giza, and 120 m above the sea surface. Why does Chikyu have such a tall derrick system? This is to help with deeper and deeper investigation of the Earth.

The drill pipes total 10,000 m in length on Chikyu. In general, there are three different kinds of “pipe” used aboard Chikyu. The most common is the regular drill pipe, each about 9.5 m long. Next is the specialized Riser Pipe, each about 27 m long. Riser pipe is used in riser drilling, and create a continuous connection from the ship to the sea floor and below. Finally, we have casing pipe, which is used to protect the borehole from collapse.

There is life everywhere – even inside deeply drilled boreholes! What an amazing world! Microorganisms, like in these photos exist – not just fossils, but living microscopic organisms in deep core samples. Yes, most of these are far too small to be seen with the naked eye. These “extremophiles” are found in extraordinary environments; without oxygen nor light, under crushing pressure, high temperature (>100 ºC), and oppressive darkness. How deep can we find living organisms in the deep Earth? Mushrooms were grown from 3600 meter deep core samples colletced off the Shimokita peninsula in July 2017! After a 20 Ma (20,000,000) year sleep, these mushrooms were nudged awake ! These cystoid spores were living on land in Siberia 20 Ma (20,000,000) years ago! Since then, the Japanese islands separated from the Eurasian continent, and some of these “Siberian fragments” held cystoid spores while slowly buried and sank deep under water to 2400 m and they survived to this very day! Chikyu recovered these spores in core samples from deep below the ocean floor and these ancient mushrooms return to our world. This is a miracle brought to the world by science!

You may know that earthquakes happen every day somewhere around the world! You might not know that for many of these earthquakes, there’s a distinct pattern. This Earthquake distribution map of the world shows earthquake epicenters as red dots. You’ll notice that most of them occur along plate boundaries, suture zones, subduction zones or along mid-ocean ridges. More than 20% of the earthquakes that occur around world happen with the Japanese islands.

Most big earthquakes occur in the ocean. When an upper plate subducts under another plate, a large earthquake can be generated, and sometimes also a huge tsunami. The world’s 4th largest tsunamigenic (tsunami-making) earthquake (Mw 9.1) struck off the Tohoku region on 11 March 2011. While this was a huge earthquake, it’s only been 120 years since geophysical observation began.

This is the Nankai Trough, a 4,000 m deep trench region where the Philippine Sea Plate is subducting underneath the Eurasian plate. Periodical large and tsunami-genic earthquakes happen here on roughly 100 – 200 - year intervals.