|
the surrounding floor, is about 2 m.; while the present crater, which displays incessant activity, has itself a diameter of 14 m. | |
| Asama (Ise) 8136. | The largest active volcano in Japan. An eruption in 1783, with a deluge of lava, destroyed an extensive forest and overwhelmed several villages. The present cone is the third, portions of two concentric crater rings remaining. The present crater is remarkable for the absolute perpendicularity of its walls, and has an immense depth—from 600 to 800 ft. It is circular, 34 m. in circumference, with sides honeycombed and burned to a red hue. |
Some of the above information is based upon Mr. C. E. Bruce-Mitford’s valuable work (see Geog. Jour., Feb. 1908, &c.).
Earthquakes.—Japan is subject to marked displays of seismic violence. One steadily exercised influence is constantly at work, for the shores bordering the Pacific Ocean are slowly though appreciably rising, while on the side of the Japan Sea a corresponding subsidence is taking place. Japan also experiences a vast number of petty vibrations not perceptible without the aid of delicate instruments. But of earthquakes proper, large or small, she has an exceptional abundance. Thus in the thirteen years ending in 1897—that is to say, the first period when really scientific apparatus for recording purposes was available—she was visited by no fewer than 17,750 shocks, being an average of something over 312 daily. The frequency of these phenomena is in some degree a source of security, for the minor vibrations are believed to exercise a binding effect by removing weak cleavages. Nevertheless the annals show that during the three centuries before 1897 there were 108 earthquakes sufficiently disastrous to merit historical mention. If the calculation be carried farther back—as has been done by the seismic disaster investigation committee of Japan, a body of scientists constantly engaged in studying these phenomena under government auspices,—it is found that, since the country’s history began to be written in the 8th century A.D., there have been 2006 major disturbances; but inasmuch as 1489 of these occurred before the beginning of the Tokugawa administration (early in the 17th century, and therefore in an era when methods of recording were comparatively defective), exact details are naturally lacking. The story, so far as it is known, may be gathered from the following table:—
| Date A.D. | Region. | Houses destroyed. |
Deaths. | |
| 684 | Southern part of Tosa | — | — | [note 1] |
| 869 | Mutsu | — | — | [note 2] |
| 1361 | Kiōto | — | — | |
| 1498 | Tōkaidō | — | 2,000 | [note 3] |
| 1569 | Bungo | — | 700 | |
| 1596 | Kiōto | — | 2,000 | |
| 1605 (31/1) | Pacific Coast | — | 5,000 | |
| 1611 (27/9) | Aizu | — | 3,700 | |
| 1614 (2/12) | Pacific Coast (N.E.) | — | 1,700 | |
| 1662 (16/6) | Kiōto | 5,500 | 500 | |
| 1666 (2/2) | Pacific Coast (N.E.) | — | 1,500 | |
| 1694 (19/12) | Ugo | 2,760 | 390 | |
| 1703 (30/12) | Tōkyō | 20,162 | 5,233 | |
| 1707 (28/10) | Pacific Coast of Kiūshiū and Shikoku | 29,000 | 4,900 | |
| 1751 (20/5) | Echigo | 9,100 | 1,700 | |
| 1766 (8/3) | Hirosaki | 7,500 | 1,335 | |
| 1792 (10/2) | Hizen and Higo | 12,000 | 15,000 | |
| 1828 (18/2) | Echigo | 11,750 | 1,443 | |
| 1844 (8/5) | Echigo | 34,000 | 12,000 | |
| 1854 (6/7) | Yamato, Iga, Ise | 5,000 | 2,400 | |
| 1854 (23/12) | Tōkaidō (Shikoku) | 60,000 | 3,000 | |
| 1855 (11/11) | Yedo, (Tōkyō) | 50,000 | 6,700 | |
| 1891 (28/10) | Mino, Owari | 222,501 | 7,273 | |
| 1894 (22/10) | Shōnai | 8,403 | 726 | |
| 1896 (15/6) | Sanriku | 13,073 | 27,122 | |
| 1896 (31/8) | Ugo, Rikuchu | 8,996 | 209 | |
| 1906 (12/2) | Formosa | 5,556 | 1,228 | |
In the capital (Tōkyō) the average yearly number of shocks throughout the 26 years ending in 1906 was 96, exclusive of minor vibrations, but during the 50 years then ending there were only two severe shocks (1884 and 1894), and they were not directly responsible for any damage to life or limb. The Pacific coast of the Japanese islands is more liable than the western shore to shocks disturbing a wide area. Apparent proof has been obtained that the shocks occurring in the Pacific districts originate at the bottom of the sea—the Tuscarora Deep is supposed to be the centre of seismic activity—and they are accompanied in most cases by tidal waves. It would seem that of late years Tajima, Hida, Kōzuke and some other regions in central Japan have enjoyed the greatest immunity, while Musashi (in which province Tōkyō is situated) and Sagami have been most subject to disturbance.
Plains.—Japan, though very mountainous, has many extensive plains. The northern island—Yezo—contains seven, and there are as many more in the main and southern islands, to say nothing of flat lands of minor dimensions. The principal are given in the following table:—
| Name. | Situation. | Area. | Remarks. |
| Tokachi plain | Yezo. | 744,000 acres. | — |
| Ishikari plain | Yezo. | 480,000 acres. | — |
| Kushiro plain | Yezo. | 1,229,000 acres. | — |
| Nemuro plain | Yezo. | 320,000 acres. | — |
| Kitami plain | Yezo. | 230,000 acres. | — |
| Hidaka plain | Yezo. | 200,000 acres. | — |
| Teshio plain | Yezo. | 180,000 acres. | — |
| Echigo plain | Main Island. | Unascertained. | — |
| Sendai plain | Main Island. | Unascertained. | — |
| Kwanto plain | Main Island. | Unascertained. | In this plain lie the capital, Tōkyō, and the town of Yokohama. It supports about 6 millions of people. |
| Mino-Owari plain | Main Island. | Unascertained. | Has 112 million inhabitants. |
| Kinai plain | Main Island. | Unascertained. | Has the cities of Osaka, Kiōto and Kobe, and 212 million people. |
| Tsukushi plain | Kiūshiū. | Unascertained. | The chief coalfield of Japan. |
Rivers.—Japan is abundantly watered. Probably no country in the world possesses a closer network of streams, supplemented by canals and lakes. But the quantity of water carried seawards varies within wide limits; for whereas, during the rainy season in summer and while the snows of winter are melting in spring, great volumes of water sweep down from the mountains, these broad rivers dwindle at other times to petty rivulets trickling among a waste of pebbles and boulders. Nor are there any long rivers, and all are so broken by shallows and rapids that navigation is generally impossible except by means of flat-bottomed boats drawing only a few inches. The chief rivers are given in the following table:—
| Length in miles. |
Source. | Mouth. | |
| Ishikari-gawa | 275 | Ishikari-dake | Otaru. |
| Shinano-gawa | 215 | Kimpu-san | Niigata. |
| Teshio-gawa | 192 | Teshio-take | Sea of Japan. |
| Tone-gawa | 177 | Monju-zan, Kōzuke | Choshi (Shimosa). |
| Mogami-gawa | 151 | Dainichi-dake(Uzen) | Sakata. |
| Yoshino-gawa | 149 | Yahazu-yama (Tosa) | Tokushima (Awa). |
| Kitakami-gawa | 146 | Nakayama-dake (Rikuchiu) | Ishinomaki (Rikuzen). |
| Tenriu-gawa | 136 | Suwako (Shinano) | Tōtōmi Bay. |
| Go-gawa or Iwa-megawa | 122 | Maruse-yama (Bingo) | Iwami Bay. |
| Abukuma-gawa | 122 | Asahi-take (Iwashiro) | Matsushima Bay. |
| Tokachi-gawa | 120 | Tokachi-dake | Tokachi Bay. |
| Sendai-gawa | 112 | Kunimi-zan (Hiuga) | Kumizaki (Satsuma). |
| Oi-gawa | 112 | Shirane-san (Kai) | Suruga Bay. |
| Kiso-gawa | 112 | Kiso-zan (Shinano) | Bay of Isenumi. |
| Arakawa | 104 | Chichibu-yama | Tōkyō Bay. |
| Naga-gawa | 102 | Nasu-yama (Shimotsuke) | Naka-no-minato (Huachi). |
Lakes and Waterfalls.—Japan has many lakes, remarkable for the beauty of their scenery rather than for their extent. Some are contained in alluvial depressions in the river valleys; others have been formed by volcanic eruptions, the ejecta damming the rivers until exits were found over cliffs or through gorges. Some of these lakes have become favourite summer resorts for foreigners. To that category belong especially the lakes of Hakone, of Chiuzenji, of Shōji, of Inawashiro, and of Biwa. Among these the highest is Lake Chiuzenji, which is 4375 ft. above sea-level, has a maximum depth of 93 fathoms, and empties itself at one end over a fall (Kegon) 250 ft. high. The Shōji lakes lie at a height of 3160 ft., and their neighbourhood abounds in scenic charms. Lake Hakone is at a height of 2428 ft.; Inawashiro, at a height of 1920 ft. and Biwa at a height of 328 ft. The Japanese associate Lake Biwa (Omi) with eight views of special loveliness (Omi-no-hakkei). Lake Suwa, in Shinano, which is emptied by the Tenriu-gawa, has a height of 2624 ft. In the vicinity of many of these mountain lakes thermal springs, with remarkable curative properties, are to be found. (F. By.)
Geology.—It is a popular belief that the islands of Japan consist for the most part of volcanic rocks. But although this conception might reasonably be suggested by the presence of many active and
