5:15 PM - 6:45 PM
[MZZ46-P03] The usage of the pyroclastic flow deposits in Tokachidake Geopark area
Keywords:Geopark, pyroclastic flow deposits, agriculture
Tokachidake Geopark is located in central Hokkaido and consists of two towns: Biei and Kamifurano Town. This region has a remarkable periglacial topography called “wavy hills'” caused by large-scale pyroclastic flow deposits. The pyroclastic flow deposits consist of Tokachi and Biei pyroclastic flow deposits. They are estimated to have been formed by a caldera-forming eruption that occurred approximately 2 to 0.8 Ma. The wavy hills reflect sunlight, making the quartz sparkle in the summer, and form the basis of a beautiful snowy landscape in the winter.
In this area, where settlement and cultivation began approximately 100 years ago, the Ainu people had not formed a village. Because it is a basin surrounded by the Taisetsu-Tokachi volcanic edifice, and the Yubari mountains, the highest temperature in summer has been recorded as 37.5 degrees Celsius, and in winter it has been recorded as low as -31.7 degrees Celsius. The average temperature difference is almost 60 degrees throughout the year, and this region is characterized by extremely rapid temperature changes. In addition, for the Ainu people, who formed villages around rivers, the rivers in this area were called “piye” (meaning greasy in Ainu languages) and “furanu-i” (meaning smelly in Ainu languages). It is considered that one of the reasons why the village had not taken root was that the environment was not suitable for them. A group of settlers came to this area from Honshu about 140 years ago. The first hoe was put into Biei Town from Hyogo Prefecture and Kamifurano Town from Mie Prefecture. At that time, clothing was thinner, the winters were even colder thanthe present, and the land had to be cultivated with great difficulty. When the fields were finally formed, the land, which was made up of pyroclastic flow deposits, had to be well drained for farming.
In addition, the wavy hills are too steep to use agricultural tractors and even today, farmers are still faced with these challenges. Furthermore, Tokachidake is an active volcano that releases gas from fumaroles every day. The Taisho mudflow caused by the 1926 eruption of Tokachidake killed 144 people. At that time, the soil was also damaged by sulfur. Although it would not have been viable as farmland if it remained as it was, the people of this area never gave up on living in harmony with Mt. Tokachidake.
In recent years, the wavy hills are covered with colorful plants that bloom profusely in the summer, and tourists come from Japan and abroad to take in the beautiful scenery. Residents will continue to coexist with Tokachidake in this active volcanic area and utilize the pyroclastic flow deposits as the foundation of their livelihood.
In this area, where settlement and cultivation began approximately 100 years ago, the Ainu people had not formed a village. Because it is a basin surrounded by the Taisetsu-Tokachi volcanic edifice, and the Yubari mountains, the highest temperature in summer has been recorded as 37.5 degrees Celsius, and in winter it has been recorded as low as -31.7 degrees Celsius. The average temperature difference is almost 60 degrees throughout the year, and this region is characterized by extremely rapid temperature changes. In addition, for the Ainu people, who formed villages around rivers, the rivers in this area were called “piye” (meaning greasy in Ainu languages) and “furanu-i” (meaning smelly in Ainu languages). It is considered that one of the reasons why the village had not taken root was that the environment was not suitable for them. A group of settlers came to this area from Honshu about 140 years ago. The first hoe was put into Biei Town from Hyogo Prefecture and Kamifurano Town from Mie Prefecture. At that time, clothing was thinner, the winters were even colder thanthe present, and the land had to be cultivated with great difficulty. When the fields were finally formed, the land, which was made up of pyroclastic flow deposits, had to be well drained for farming.
In addition, the wavy hills are too steep to use agricultural tractors and even today, farmers are still faced with these challenges. Furthermore, Tokachidake is an active volcano that releases gas from fumaroles every day. The Taisho mudflow caused by the 1926 eruption of Tokachidake killed 144 people. At that time, the soil was also damaged by sulfur. Although it would not have been viable as farmland if it remained as it was, the people of this area never gave up on living in harmony with Mt. Tokachidake.
In recent years, the wavy hills are covered with colorful plants that bloom profusely in the summer, and tourists come from Japan and abroad to take in the beautiful scenery. Residents will continue to coexist with Tokachidake in this active volcanic area and utilize the pyroclastic flow deposits as the foundation of their livelihood.