| Japan is famous as a hot spring country and
Oita Prefecture is particularly blessed with hot springs. Oita residents
have been close to hot springs from time immemorial, a fact made clear
by a historical account of hot and mineral springs in the "Bungo
Fudoki (Oita Regional Topography)" that was edited during the
Nara Era. |
Most Hot Springs Are Volcanic |
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Most hot springs are volcanic as their source
of heat and chemical elements is the magma generated from volcanoes.
In Oita, the magma sources are the new volcanoes of Tsurumi, Yufu
and Kuju ranging from east to west at the center of the prefecture.
The Beppu, Yufuin and Kuju areas form the core of the sources and
each place is known as a major hot spring area in Japan. The center
part of Oita Prefecture is a part of each of these areas and thus
is one of the world's most prominent hot spring district.
Without new volcanic activity these days, it was said to be difficult
to find new hot springs in the northern and southern area. But another
usable hot spring was found by boring over 1,000m deep into the earth
for groundwater that is non-volcanic but rather, heated by heat currents
inside the earth. A typical example is the kind of hot springs in
Oita Plain which have been developed since 1975, and Oita City is
now one of the most famous hot spring cities in Japan. |
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High Temperatures and a Variety of Hot Springs |
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In Oita Prefecture, 38 cities, towns and villages
have hot springs, according to figures as of the end of March, 2000.
The total number of spring sources is 4,749, including unused ones,
and this makes up 18% of all the sources in Japan. The output of the
hot spring water is about 26,000l per minute, which accounts for 10%
of the amount produced by the whole country. Although Oita occupies
less than 2% of the total land area in the country, a large number
of hot springs are concentrated in this small area.
The remarkable thing is that about 85% of the sources have water temperatures
over 42 , and some
sources in the volcanic area produce hot water and steam at boiling
point. Moreover, the quality of the water varies with every spring,
except for radioactive water. That is to say, Oita's hot springs not
only boast of a large number of spring sources and high output of
springs, but also of a quantity of high temperature springs and a
variety of water quality. |
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The Best Hot Spring Prefecture in Japan |
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The basic elements of hot springs are water,
heat and chemical elements. On one hand, the southewestern area in
Japan abounds in rainfall due to the humid and mild climate. On the
other hand, when the Philippines Sea Plate swept toward Kyushu Island
in a dynamic movement of the earth, it sank under the island and generated
magma. The magma generated heat and chemical elements, and then split
up the island into north and south, crushed the land and made the
spots where the rainwa t e r, heat, and chemical elements meet. That
was how the hot springs were generated, and Oita Prefecture is located
right where the activity took place.
The Philippines Sea Plate's sinking raised the underground temperature
ofthis area. As the underground temperature on Oita Plain increases
by about 5to 6.5for
every 100m deeper it goes, the water is hot enough at 800m deep and
may be used as a non-volcanic spring.
With the development of non-volcanic springs added to the old volcanic
ones, Oita Prefecture, "The best hot spring prefecture in Japan",
is improving where natural assets are concerned. |
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Kuju Mountain Ranges
Steam rising from hot springs (Beppu City)
(Outline of Hot Springs in Japan)
Top5 prefectures in the number of hot spring sources
| Number
of sources |
| Oita prefecture |
4,762vents |
| Kagoshima prefecture |
2,804vents |
| Shizuoka prefecture |
2,289vents |
| Hokkaido |
2,200vents |
| Kumamoto prefecture |
1,345vents |
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Top5 prefectures in output of spring water
| Output
of Spring Water |
| Hokkaido |
300,920
l/min |
| Oita prefecture |
266,228l/min |
| Kagoshima prefecture |
200,028l/min |
| Aomori prefecture |
166,526l/min |
| Nagano prefecture |
132,187l/min |
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Sujiyu Hot Spring (Kokonoe Town)
Nagayu Kaniyu Hot Spring (Naoiri Town)
qOutline of Hot Springs in Oita prefecturer
Top5 cities,towns and villeges in the number of hot spring sources
| Number
of sources |
| Beppu City |
2,850vents |
| Yufuin Town |
888vents |
| Kokonoe Town |
303vents |
| Oita City |
185vents |
| Amagase Town |
117vents |
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Top5 cities,towns and villeges in output of spring
water
| Output
of Spring Water |
| Beppu City |
95,434l/min |
| Kokonoe Town |
61,704l/min |
| Yufuin Town |
44,699l/min |
| Oita City |
16,196l/min |
| Amagase Town |
10,548l/min |
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