[Yuza Town, Yamagata Prefecture] Shonai Plain enriched with blessings from Mt. Chokai - Yusa/Sakata

Mt. Chokai is a rare mountain that has two peaks (Higashichokaisan Shinzan and Nishichokaisan Nabemori) that rise from 0m above sea level in the Sea of ​​Japan to the summit at 2,236m.Because of the beauty of its appearance“Dewa Fuji”It is called. It is an active volcano, and the people who live at its base in areas such as Yusa, Sakata, Kisakata (Nikaho City, Akita Prefecture), and Yuri (Yurihonjo City, Akita Prefecture) sometimes vent their anger by spewing fire that shakes the earth. While fearing Mt. Chokai, it has also been worshiped as the mountain where the gods dwell, as it brings abundant water.

Mt. Chokai took its current form due to a large eruption during the Edo period.

Mt. Chokai began its activity about 550,000 years ago, and about 160,000 to 20,000 years ago lava covered the surface of Mt. Nishi-Chokai (Nabemori Lava Dome/Nabemoriyogan Dome/1,652 m above sea level). It has been. After about 20,000 years ago, Mt. Higashichokai in the eastern part of the mountain was formed. About 2,600 years ago, the summit of Mt. Higashichokai collapsed, and the lava formed a crater floor (caldera). The sediments created the topography at the foot of the mountain. Of the two central cones of Mt. Higashichokai, Shinzan (2236m) is a lava dome created by an eruption in 1801, and is also known as Mt. Kyowadake. I am.

Mt. Chokai eruptions occurred frequently until the late Heian period (900s). After that, there were no records of eruptions in the mid-1600s, and activity started again around 1659. In 1801, the largest eruption in history occurred.

Traces of a large eruption left on the mountain and the Shonai Plain

The phreatic eruptions that began in 1800 gradually became more intense, and in late August 1801 a large explosion occurred, killing eight climbers. In 1804 (Bunka 1), a large earthquake (Shogata Earthquake) occurred, causing extensive damage to the area at the foot of the mountain.

No large-scale eruptions have occurred since then. The most recent eruption was a small-scale phreatic eruption that occurred near Mt. Shinzan in 1974, with mudflow and ash fall confirmed. Additionally, in 1987 (Showa 62), an earthquake swarm occurred.

The active volcano Mt. Chokai changes the shape of the earth and attacks people every time it erupts or has an earthquake. Traces still remain today, such as faults and lava flows, which are unique to the Shonai region. Its unique topography is a global park "Mt. Chokai/Tobishima Geopark"is certified.

INFORMATON

• Mt. Chokai/Tobishima Geopark
• Phone number: 0184-62-9777 (Mt. Chokai/Tobishima Geopark Promotion Council Secretariat)
• URL: Mt. Chokai/Tobishima Geopark

Lava dome Shinzan with the remains of a violent explosion

Shinzan is a lava dome that was created during the huge explosion that occurred on Mt. Higashichokai in 1801.It is 70m high from the crater floor. It is possible to climb up to the new mountain, and it takes about 5 hours and 30 minutes from the Ohira exit of the mountain trail (Yusa Town, Yamagata Prefecture) and the Hokodate exit of the mountain trail (Nikaho City, Akita Prefecture). It is approximately 20 minutes from Omuro Hut (Omuro Sanrojo/Omuro Sanrojo/Accommodation) located next to the main shrine at the summit of the mountain. The large rock near the main shrine at the summit is a volcanic bomb that was thrown during the birth of Mt. Shinzan and weighs 300 tons. This shows how violent the eruption of Mt. Shinzan was.

Lake Chokai, a crater lake full of water from melting snow

Lake Chokai is a crater lake located at an altitude of approximately 1,600m on Mt. Nishichokai, about 3km west of Mt. Niizan (Mt. Higashichokai). It is approximately 200m in diameter and has an oval shape extending from north to south. The water comes from melting snow that has fallen, making it a rare lake that freezes all the way to the bottom, which is 4.7m deep in the middle of winter. Torinoumi Mihama Shrine is located nearby, and there is an accommodation facility called Mihama Koya (Mihama Sanrojo).

Normal fault group of Mt. Chokai running along the mountainside

There is a group of active faults unique to volcanoes on the mountainside of Mt. Chokai. Many of them are distributed from the horseshoe-shaped caldera of Mt. Nishichokai (Nishichokaiba-shaped caldera) to the west slope, and near Gassan Mori (1,650 m). The active fault of Mt. Chokai is a normal fault, which is often seen in Kyushu, but is rare in northern Japan.The one on the west side of the mountain is called the Arizawa Fault, and is a 2.5km long cliff with a maximum drop of about 30m. The Gassanmori Fault is 1.5km long with a maximum drop of approximately 50m.

The Shonai Plain east edge fault zone continues in a straight line for 35km.

The Shonai Plain has active fault lines that thread along the edge of the plain. Shonai Plain eastern edge fault zone It extends approximately 35km south from Yusa Town, at the foot of Mt. Chokai, to Sakata City, Shonai Town, and Tsuruoka City. As of 2022, the earthquake occurrence rate within 100 years in the Shonai Plain East Fault Zone is 0% in the northern part and less than 20% in the southern part (Ministry of Education, Culture, Sports, Science and Technology, Research and Development Bureau, Earthquake and Disaster Prevention Research Division, Earthquake Headquarters, October 19, 2009) However, it is said to have caused the Shonai Earthquake in 1894 (Meiji 27), and as it is a live fault, it is necessary to be extremely careful.

The rich water of Mt. Chokai that nourishes the Shonai plains

The Motomachi district in the center of Yuza Town is located on the alluvial fan of the Gekko River, which originates from Mt. Chokai, and is extremely rich in groundwater. Therefore, when the wells are dug, water gushes out, and there are approximately 300 of them, producing an amount of 4,200 tons per day.

The Yusa Motomachi Yusui Group (Machimeguri Park) is a walking course along the Gekko River from Yusa Station, where you can freely enjoy the 14 artesian wells courtesy of the owners. However, although it has passed the test, it is not sterilized, so drink at your own risk.

INFORMATON

• Facility name: Yusa Motomachi Yusui Group (Machimeguri Park)
• Location: Around JR Yusa Station, Yuza-cho, Yamagata Prefecture
• Phone number: 0234-72-5666 (Yusachokai Tourism Association)
• URL: Machimeguri Park

“Miko no Mizu” is a blessing from the mountain of God that is essential for daily life.

Miko no Mizu is a washing place that uses spring water in the Mega village of Yuza Town. Mega is a village on the coastline where the foot of Mt. Chokai, the mountain of the gods, sinks into the Sea of ​​Japan, and the spring water is called "Shinsen no Mizu" because it is drawn from the mountain of the gods. The spring water is divided into six tanks and divided according to usage.

INFORMATON

• Facility name: Miko no Mizu
• Location: 64 Fukiura Mega, Yusa-machi, Akumi-gun, Yamagata Prefecture
• Phone number: 0184-62-9777 (Mt. Chokai/Tobishima Geopark Promotion Council Secretariat)
• access
• Car: From Yamagata Expressway Sakata Minato IC, take National Route 7 towards Akita for about 25 minutes.
• Railway/Approximately 5 minutes walk from JR Uetsu Main Line Mega Station
• Toilet: None
• Parking: None
• URL: Miko no Mizu

GOOGLE MAP

Ushiwatari River and Maruike made of spring water

The Ushiwata River is a short river with a total length of about 4 km located at the base of Mt. Chokai on the Sea of ​​Japan side, and almost 100% of its flow is spring water.The water temperature is around 11 degrees Celsius throughout the year, and salmon migrate upstream in the fall.

Maruike-sama (Maruike-sama) is a spring-fed pond with a diameter of approximately 20m and a depth of 3.5m located near the Ushiwatari River. It is one of the sources of the Ushiwata River, and on its banks is Maruike Shrine, whose deity is Maruike-sama.

INFORMATON

• Facility name: Ushiwatari River and Maruike-sama
• Phone number: 0234-72-5666 (Yusachokai Tourism Association)
• access
• Car: From Yamagata Expressway Sakata Minato IC, take National Route 7 towards Akita for about 25 minutes.
• About 5 minutes by car from Fukiura Station on the Railway/JR Uetsu Main Line
• Toilet: Available (temporary)
• Parking: Available (free)

GOOGLE MAP

Chokaisan Omonoki Shrine, whose object of worship is Mt. Chokai, the mountain of the gods.

Chokaisan Oimonoki Shrine is a shrine where prayers were offered to quell the anger of Mt. Chokai, and it is said to have been built in 564 (the 25th year of the 29th Emperor Kinmei) during the late Kofun period. The main hall of the main shrine, Chokaisan Oimonoki Shrine, is located on the summit of Mt. Chokai near Mt. Niiyama, and at the foot of the mountain are Fukura (Fukura/Chorkaisan Omonoki Shrine Fukiuraguchinomiya) and Warabioka (Chorkaisan Omonoki Shrine Warabiokaguchinomiya). There are two Satomiya shrines called ``Kuchinomiya''.

In the late Heian period, it was ranked as the No. 1 shrine in Dewa Province and is the highest shrine in Dewa Province. The main shrine at the top of the mountain is rebuilt every 20 years, just like Ise Grand Shrine.

INFORMATON

• Facility name: Chokaisan Daimonoki Shrine mountaintop main hall
• Location: Mt. Chokai summit
• Phone number: 0234-77-2301

GOOGLE MAP

INFORMATON

• Facility name: Chokaisan Omonoki Shrine Fukiuraguchinomiya
• Location: 1 Fukura, Fukiura, Yusa-machi, Akumi-gun, Yamagata Prefecture
• Phone number: 0234-77-2301
• access
• By car: Exit the Yamagata Expressway at Sakata Minato IC and take National Route 7 towards Akita for about 20 minutes.
• Railway/Approximately 10 minutes walk from Fukiura Station on the JR Uetsu Main Line
• There is a toilet

GOOGLE MAP

INFORMATON

• Facility name: Chokaisan Omonoki Shrine Warabiokaguchinomiya
• Location: 51 Matsugaoka, Kamwaraoka, Yuza-machi, Akumi-gun, Yamagata Prefecture
• Phone number: 0234-77-2301
• access
• Car: Approximately 20 minutes from Nihonkai-Tohoku Expressway Sakata Minato IC
• Railway/About 10 minutes by car from JR Uetsu Main Line Yusa Station
• URL: Chokaisan Omonoki Shrine

GOOGLE MAP

16 Arhat Rocks carved into lava to commemorate marine accidents

The 16 Arhat Rocks (Juroku Rakan Rocks) are carved stone Buddhas carved into the lava that flowed from Mt. Chokai on the coast near the Fukiura fishing port facing the Sea of ​​Japan.A total of 22 Buddha statues are carved here, including 16 Arhat statues (saints who have reached the highest level of training), Manjushri Bodhisattva, and Fugen Bodhisattva.

The Magaibutsu was carved in the first year of the Meiji era, mainly by the priest Kankai of Fukiura Kaizenji Temple, as a memorial service for the fishermen who died in maritime accidents, and a prayer for safety at sea.

INFORMATON

• Facility name: Juroku Rakan Rock
• Location: Fukiura Nishitate, Yusa-machi, Akumi-gun, Yamagata Prefecture
• Phone number: 0234-72-5666 (Yusachokai Tourism Association)
• Free tour
• access
• Car: Approximately 15 minutes from Yusahiko IC on the Nihonkai-Tohoku Expressway
• Railway/Approximately 15 minutes walk from Fukiura Station on the JR Uetsu Main Line
• URL: 16 Rakan Rocks

GOOGLE MAP

INFORMATON

• Name: Mt. Chokai/Tobishima Geopark
• Phone number: 0184-62-9777
• URL: Mt. Chokai/Tobishima Geopark

• Name: Yusa Chokai Tourism Association
• Phone number: 0234-72-5666
• URL: Yusa Chokai Tourism Association