Vol.02 GSA (Geo Space Adventure)

Kamioka Castle

View of the town area from Kamioka Castle. This photo was taken in April so snow can still be seen along the front side of the mountain.

Called the “Happy junction of 6 roads” in the local area, this is a strange intersection formed in mysterious angles.

Kamioka town central public hall serves as our reception area. It is run by volunteer staff from the “GSA Executive Committee” which is mostly made up of citizens from Hida-city.

Boarding the bus next to the town hall. Tour members were a mixed group ranging from elementary school kids to senior citizens. There are 8 bus trips per day and I took part in the earliest group leaving at 7 in the morning.

We set off the microbus and arrived at the Atotsu-mine entrance from where we will enter the huge underground space in the mine. During the bus trip, our tour conductor who was one of the volunteer staff told us the rules to follow while in the mine.

Here we just arrived at the Atotsu-mine entrance along the banks of Atotsu River. We are finally going inside the mine! Even the air was cool here and it felt a little bit cold.

After moving 1,500 meters horizontally from the Atotsu-mine entrance, we got off the bus. We then walked along the mine passage seen in the next picture.

Along the passage everyone shut off their flashlights to view a startling attraction. We found ourselves surrounded a true jet black world impossible to experience above ground. Suddenly we felt wrapped in a feeling of real adventure!

We reached the Kamioka-mine itself. This mine has a very old history. Digging first started in the Nara Period (8th century in Japan). The mine mainly produced zinc, lead, and silver ore.

A short show is given that recreates the digging during the Edo era (17th to 19th in Japan). The GSA volunteer staff enthusiastically play their roles in this show. (But wait! It looks very cold! Well, even so this is a popular job among the volunteer staff!)

This heavy-duty equipment is called a LHD (load-haul and dump) machine. The back section has been lowered to allow use inside the mine.

Unique experience inside the mine. Sitting in the driver’s seat while also getting a souvenir photo taken -- what a thrill!

Heavy equipment called Jumbo Drill easily drills holes in solid rock for planting dynamite.

We got a live demonstration of the Jumbo Drill. It drills holes in super-hard solid rock in just seconds. Dynamite is then planted in these holes and exploded.

Conceptual image view of Super-Kamiokande. During the GSA, you can observe the top of tank in the experimental area, from the mine passageway.

Lonely mine passageway. The passage and its walls are coated with underground water flow from the mountain. There is plenty of underground water here to supply the pure water to fill into the Super-Kamiokande tank.

We just arrived at the entrance to the Super-Kamiokande experimental laboratory.

Here we are shown a video describing the Super-Kamiokande facility and the experiments performed here. The wall at the rear is crammed with signatures of famous person who visited this facility! This really gives you the feeling that this is a research site attracting attention from all over the world!

Here we tour the ceiling section of the tank. Beneath our feet where we are standing are some 50,000 tons of water and photomultiplier tubes (super-high sensitivity photosensors for detecting elementary particles) and now we are right in the middle of this research. Just thinking about it gives you goosebumps!

Here is a picture from right inside the Super-Kamiokande tank! It is a long way down, very deep, and yes, very scary! The water level was very low at this time, only about 2 meters or roughly seven feet.

The photomultiplier tubes are densely set into the walls of the tank. Each of the tubes is 20 inches in diameter (about 50 centimeters), so you can get some idea about how big this space is can’t you?

The bottom of the tank. Countless photomultiplier tubes set in the walls are reflected in the clear water. It is very mysterious and wonderful.

A teacher from Tokyo University gave a presentation on neutrinos at the GSA. Here I finally found out the reason we couldn’t open the tank and look inside. The teacher will answer any questions you want to ask. It was really interesting and I learned a lot.

Leaving the mine and going back outside the mountain by the custom mine transport vehicle.

Here you can buy various kinds of souvenirs on sale including goods such as official helmets, work gloves, flashlights and parkas clearly bearing the GSA logo as well as “black dark manju” ”mine manju” which are buns filled with different flavored bean jam, ”red loincloth noodle” and ”black dark noodle.” These are all popular favorites!

On the way home we got a view of the Nishizato Bridge at dusk. Kamioka castle stands in the background. Wow! It was fun day packed with sights and thrills!