It has been abundantly demonstrated by careful observations that the
east coasts of Japan are slowly rising. This phenomenon was first
noticed in the case of the plain on which stands the capital, Tokyo.
Maps of sufficiently trustworthy accuracy show that in the 11th
century Tokyo Bay penetrated much more deeply in a northern direction
than it does now; the point where the city's main river (Sumida or
Arakawa) enters the sea was considerably to the north of its present
position, and low-lying districts, to-day thickly populated, were
under water. Edmund Naumann was the discoverer of these facts, and his
attention was first drawn to them by learning that an edible sea-weed,
which flourishes only in salt water, is called Asakusa-nori, from the
place (Asakusa) of its original provenance, which now lies some 3 m.
inland. Similar phenomena were found in Sakhalin by Schmidt and on the
north-east coast of the main island by Rein, and there can be little
doubt that they exist at other places also. Naumann has concluded that
"formerly Tokyo Bay stretched further over the whole level country of
Shimosa and Hitachi and northwards as far as the plain of Kwanto
extends;" that "the mountain country of Kasusa-Awa emerged from it an
island, and that a current ran in a north-westerly direction between
this island and the northern mountain margin of the present plain
toward the north-east into the open ocean."
_Mineral Springs._--The presence of so many active volcanoes is
partially compensated by a wealth of mineral springs. Since many of
these thermal springs possess great medicinal value, Japan may become
one of the world's favourite health-resorts. There are more than a
hundred spas, some hot, some cold, which, being easily accessible and
highly efficacious, are largely visited by the Japanese. The most
noteworthy are as follows:--
Name of Spa. Prefecture. Quality. Temp., F°.
Arima Hiogo Salt 100
Asama Nagano Pure 111--127
Asamushi Aomori Salt 134--168
Atami Shizuoka " 131--226
Beppu Oita Carbonic Acid 109--132
Bessho Nagano Pure or Sulphurous 108--113
Dogo Ehime Pure 70--110
Hakone Kanagawa Pure, Salt or Sulphurous 98--168
Higashi-yama Fukushima Pure or Salt 117--144
Ikao Gumma Salt 111--127
Isobe " " Cold
Kusatsu " Sulphurous 127--148
Nasu Tochigi Sulphurous 162--172
Noboribetsu Ishikari " 125
Shibu Nagano Salt 98--115
Chiuzenji Shizuoka Carbonate of Soda and
Sulphur 114--185
Takarazuka Hiogo Carbonic Acid Cold
Ureshino Saga " 230
Unzen Nagasaki Sulphurous 158--204
Wagura Ishikawa Salt 180
Yamashiro " " 165
Yunoshima Hiogo " 104--134
_Climate._--The large extension of the Japanese islands in a northerly
and southerly direction causes great varieties of climate. General
characteristics are hot and humid though short summers, and long, cold
and clear winters. The equatorial currents produce conditions
differing from those existing at corresponding latitudes on the
neighbouring continent. In Kiushiu, Shikoku and the southern half of
the main island, the months of July and August alone are marked by
oppressive heat at the sea-level, while in elevated districts a cool
and even bracing temperature may always be found, though the direct
rays of the sun retain distressing power. Winter in these districts
does not last more than two months, from the end of December to the
beginning of March; for although the latter month is not free from
frost and even snow, the balminess of spring makes itself plainly
perceptible. In the northern half of the main island, in Yezo and in
the Kuriles, the cold is severe during the winter, which lasts for at
least four months, and snow falls sometimes to great depths. Whereas
in Tokyo the number of frosty nights during a year does not average
much over 60, the corresponding number in Sapporo on the north-west of
Yezo is 145. But the variation of the thermometer in winter and summer
being considerable--as much as 72° F. in Tokyo--the climate proves
somewhat trying to persons of weak constitution. On the other hand,
the mean daily variation is in general less than that in other
countries having the same latitude: it is greatest in January, when it
reaches 18° F., and least in July, when it barely exceeds 9° F. The
monthly variation is very great in March, when it usually reaches 43°
F.
Meteorology.
During the first 40 years of the _Meiji_ era numerous meteorological
stations were established. Reports are constantly forwarded by
telegraph to the central observatory in Tokyo, which issues daily
statements of the climatic conditions during the previous twenty-four
hours, as well as forecasts for the next twenty-four. The whole
country is divided into districts for meteorological purposes, and
storm-warnings are issued when necessary. At the most important
stations observations are taken every hour; at the less important, six
observations daily; and at the least important, three observations.
From the record of three decades the following yearly averages of
temperature are obtained:--