Ōwakudani

Ōwakudani
	View of the front part of the valley from the Hakone cable car .
location	Kanagawa Prefecture , Japan
Mountains	Hakone
Geographical location	35 ° 14 ′ 31 ″ N , 139 ° 1 ′ 15 ″ E Coordinates: 35 ° 14 ′ 31 ″ N , 139 ° 1 ′ 15 ″ E
height	1040 m TP

f

Ōwakudani ( Japanese 大涌谷 , dt. "Large boiling valley") is a volcanic valley on the Japanese main island of Honshu . It is located in Kanagawa Prefecture in the Hakone metropolitan area , about 80 kilometers southwest of Tokyo . The valley extends at an altitude of 1040 meters on the north side of Komagatake, one of the main cones of the Hakone volcano . It is known for the numerous sulphurous hot springs and fumaroles from which volcanic gases escape.

geography

Ōwakudani is located near the caldera that was created during the last eruption of the Hakone volcano over 3000 years ago. The entire area is an active volcanic zone with fumaroles and hot springs . The area around the valley belongs to a huge volcano that collapsed through two huge eruptions, the first about 180,000 years ago and the second about 49,000–80,000 years ago, and formed a large caldera. To the west of Ōwakudani is Lake Ashi , a seven kilometer long crater lake . The Kamiyama and Komagetake mountains, bordering Ōwakudani to the south, are two volcanic peaks in the center of the great Hakone caldera.

Volcanism

The last major Magma - eruption occurred about 3000 years ago, since then have been no major incidents. There were three phreatic explosions in the Ōwakudani area between the 12th and 13th centuries .

20th century

In 1933 changes were found in the fumaroles , and the water output at the Ubako Onsen also changed . That same year, a fumarole explosion in Ōwakudani killed a person.
From September 1974 to February 1978 there were further changes in the area around wakudani, fumaroles changed their position and trees began to wither and die.
Weak earthquakes were also registered in 1987 and 1992 at depths of 20 to 23 km. At the center of Ōwakudani there was a slight increase in the ground.
On April 22, 1991, around 300 earthquakes (magnitude ≤ 2.5) were detected between 10:00 a.m. and 1:00 p.m. The epicenter of most of the tremors was about 3 miles below the caldera. On April 24th, the situation returned to normal and no change in surface activity was observed.

21st century

Increased seismic activity was recorded in the area between June and October 2001. There was a slight bulge near the center. Other smaller earthquakes were recorded at the northern end of Lake Ashi . Shortly after the earthquake, an enlargement of the fumarole area in wakudani was noted. The steam output in some places in Ōwakudani increased sharply.
Between March and April 2011, more precisely since the Tōhoku earthquake , increased seismic activity was measured in the north of Ōwakudani. In addition to many smaller earthquakes, there were also two stronger ones on March 11th and 21st.
In February 2013 around 1400 smaller earthquakes were registered, but no eruption followed and the situation subsequently calmed down again.

Volcanic earthquake activity in Hakone (2015)

On April 26, 2015, increased seismic activity was again detected in the area.
As of May 6, 2015, the area around Ōwakudani was closed to visitors. Due to the increased seismic activity and smaller volcanic eruptions, the area around the cable car, access roads and hiking trails within a radius of 300 m had to be closed. The Japanese Meteorological Authority raised the alert to level 2. On that day alone, 115 earthquakes were recorded. An increase in water pressure could be determined at the hot springs.
Between May 14 and May 17, 2015, hardly anything changed in the seismic activity. At the bottom of the hot spring at Ōwakudani, an elevation of 12 cm was found in the ground. This increase affects the area in a radius of approx. 200 m. On May 15, around 471 minor earthquakes were registered.
On June 29th, 14 earthquakes with a magnitude of 1.9 to 3.2 were measured.
As of June 30, 2015, after seismic activity increased again, according to the Japanese Meteorological Authority, there was alert level 3 and the radius was increased to a good 1 km.
On September 11, 2015, the Japanese Meteorological Authority lowered the alert level back to 2. The radius of the exclusion zone was thus reduced, but the Hakone cable car remains out of service.
Since July 27, 2016, the area including the cable car but without the hiking trails has been open to visitors daily from 9 a.m. to 5 p.m.
On May 19, 2019, the alert level was raised again to level 2. The local government therefore again restricted access to the area. The operation of the cable car was also temporarily suspended.

tourism

Kuro-tamago : Hard-boiled black eggs

Many tourists come to Ōwakudani for the view, to enjoy the view of Mount Fuji , watch the volcanic activity, and eat kuro-tamago ( 黒卵 , "black eggs"). These are special onsen tamago in which dissolved sulfates and iron ions from the sulfur water sources turn the skin black. Unlike the usual onsen tamago, these eggs are hard-boiled due to the extreme heat of the springs. Eggs are said to have a long life and it is said that for every egg you eat you should live seven years longer.

View of Ōwakudani from the Hakone cable car.

Ōwakudani can be reached using a Funitel , the Hakone cable car . This runs between the stations Sōunzan and Tōgendai. Sōunzan station can be reached with the Hakone Tozan Cable Car from Gōra . At the other end is Tōgendai station on the north shore of Lake Ashi . The station is connected to Moto-Hakone and Hakone-machi by scheduled boats.

Next to the cable car there is also a road that leads directly to the visitor center. Either you drive on the national road 1 to Kowakudani and from there on a side road, or you come from the national road 138 to Sengokuhara and from there on a side road to Kojiri and on to the visitor center.

Web links

Commons : Ōwakudani - collection of images, videos and audio files

Tourism information (English)
Description of the valley on japan-guide.com including directions (English)
Ōwakudani webcam

Individual evidence

[mustlovejapan-1-1] Must Love Japan - Owakudani

[volcanodiscovery-1-2] Volcanodiscovery.com - Hakone

[hakoneyama-1-3] 56. Hakoneyama - Monitoring Report by JMA from 2011

[tokyo-ac-1-4] Hakone Volcano, Central Japan

[volcano-si-edu-1-5] Smithsonian Institution -Bulletin Report: April 1991 (BGVN: 16:04)

[thewatchers-1-6] The Watchers: Hakoneyama volcano activity rises to a new level, Japan

[japantimes-2-7] A ^b The Japan Times - News: Volcano alert raised for Mount Hakone after small eruption

[asienspiel-1-8] Asienspiegel: A volcano awakens

[japantimes-1-9] The Japan Times - News: No-go zone declared at Hakone as officials raise volcano alert

[hakone-zenzan-1-10] Hakone - Notification: About restricted area around Oowakudani

[pref-kanagawa-11] A ^b Kanagawa Prefecturial Government: Information on Hakone & Owakudani

[hakone-japan-12] About volcanic activity in HAKONE