浅間山 - Asamayama - 10/29/2022

Mount Asama (浅間山, Asama-yama) is an active complex volcano in central Honshū, the main island of Japan. The volcano is the most active on Honshū. The Japan Meteorological Agency classifies Mount Asama as rank A. It stands 2,568 metres (8,425 ft) above sea level on the border of Gunma and Nagano prefectures. It is included in 100 Famous Japanese Mountains.

Mount Asama sits at the conjunction of the Izu–Bonin–Mariana Arc and the Northeastern Japan Arc. The mountain is built up from non-alkali mafic and pyroclastic volcanic rocks dating from the Late Pleistocene to the Holocene. The main rock type is andesite and dacite.

A University of Tokyo volcano observatory is located on the mountain's east slope. Volcanic gas emissions from this volcano are measured by a Multi-Component Gas Analyzer System, which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity. There is also another mountain called Asama (朝熊山, Asama-yama) of only 555 meters in Mie Prefecture.

Google Earth Link Here and by clicking the image below.

Getting Started: From central Takasaki where I was staying, I departed at about 6 AM for what was about 1.5 hour drive to the trailhead for Asama. Here is the AllTrails link which shows the hike as about 13.2 KM out and back (which is the route I took). If arriving by car (which was my method) you are going to park at the Asamayamaso Shukuhakushayo Parking Lot 浅間山荘 宿泊者用駐車場. There was a parking attendant/guide there who also collected 500 Yen. There is an upper parking area and lower. The upper was already full so I was directed down the hill to the lower. I was driving a Toyota Yaris (a very small car) and even with the gravel roads, I was able to make it fine.

2D View in AllTrails

3D View in AllTrails

3D View, back side up to Maekake.

Check-in Station

Gazan 牙山

Kazan-kan 火山館

Shrine

Staring at Kurofuyama (across) which was an older and active rim (peak) over 20,000 years ago

This is the Maekake rim below and the closest allowable hike for a view of the Asama crater.

See also below for Google Earth illustration on the various rims from the history of Asama. Mount Asama grew from a series of smaller peaks, including Kurofu (active some 20,000 years ago), Hotokeiwa (active between 20,000 and 10,000 years ago), and Maekake (active from 10,000 years ago). Asama has erupted frequently since the Meiji era (1868–1912).

Looking directly at Asama.

View of Mount Fuiji from Maekake rim at Asama.

One of the friendly hikers I passed up earlier on the trail and who I saw again later at the peak. She has climbed over 100 peaks in her lifetime but this was also her first time hiking Asama. What an inspiration!

Looking back down Maekake rim before heading down.

The end, wrapping up a long day of hiking. Beautiful time to hike in the fall season with changing leave color. Magical.

I will be posting video as well shortly on Youtube.

For those also interested and in a prior trip I took back in 2017, on the other side of Asama, there is the Onioshidashi Volcanic Park. This park also has a beautiful temple and very short hiking trails with some interesting shaped geology. To access this park and if going by train, stop at the Nakakaruizawa Station, then you can take the local bus from there (cheapest option). Taxi's are also available however more expensive. Additionally at the station are plenty of coin lockers for luggage storage (large, medium, and small).