Aso Caldera
Aso Caldera

By Evan

As mentioned in my last post, I currently am spending some time in Japan, in Kumamoto, Kyushu (i.e. southern Japan). The major attraction of Kumamoto, besides the ubiquitous Kumamon, is without a doubt Mt Aso. The Aso caldera (essentially a giant hole caused by the collapse of a volcano after an eruption, or more violently from an actual eruption) is one of the largest in the world. The signs on the volcano claims this is the largest caldera in the world, but I suspect that Toba is actually larger. Being inside of the caldera is impressive, like the inside of a steep bowl. The caldera formed in four major eruption episodes between 300,000 and 90,000 years ago, with the final eruption causing the majority of it. Here are some pictures of my visit from last weekend.

The active vent on Mt. Aso was particularly active the day I went, spewing out lots of sulphurous steam.
The active vent on Naka-Dake was particularly active the day I went, spewing out lots of sulphurous steam.
"Bomb" shelters were erected at the tourist site to protect people in case the volcano erupts.
“Bomb” shelters were erected at the tourist site to protect people in case the volcano erupts. Came in handy during the eruption in 1992.

 

Some nice layering caused by various ash falls and eruptions.
Some nice layering caused by sequences of ash falls and eruptions.
In front of the vent on Mt. Naka. The sulphurous cloud forced us to retreat shortly after this photo, and completely ruled out a trip into the volcano (the sulphur, it burns!)
In front of the vent on Naka-Dake. The sulphurous cloud forced us to retreat shortly after this photo, and completely ruled out a trip into the volcano (the sulphur, it burns!)

 

There is a beautiful turquoise coloured lake at the bottom of the vent, but it was largely obscured by the steam.
There is a beautiful turquoise coloured lake at the bottom of the vent, but it was largely obscured by the steam.
This inverted rice-bowl shaped hill is apparently known as "Rice Hill". Apparently the legend is that the gods made this hill and distributed the rice to the poor peasants (accounting for the dimple at the top). This small volcano is now a cattle pasture.
This inverted rice-bowl shaped hill is apparently known as “Rice Hill”. Apparently the legend is that the gods made this hill and distributed the rice to the poor peasants (accounting for the dimple at the top). This small volcano is now a cattle pasture.

 

This may look like a mountain, but it is actually the wall of the caldera. It is actually relatively flat on top.
This may look like a mountain, but it is actually the wall of the caldera. It is relatively flat pastureland on top.
View from the rim of the north side of the Aso caldera. This place is known as Daikanbo, which literally means "great big view".
View from the rim of the north side of the Aso caldera. This place is known as Daikanbo, which literally means “great big view”. It was pretty late in the day when I took this photo, but you can still somewhat see the steam from Naka-Dake in the center of the photo. Note how flat it is on the bottom of the crater, as it was likely a lake for some time. Great place for farming, but I don’t know if I would want to live in the city of Aso, located right in the middle of the caldera.