Japan is an archipelago of islands that are the protruding summits of a huge mountain chain formed by plate tectonics and volcanism in the northwestern Pacific Ocean. The islands form an irregular crescent southwest from Russia's Sakhalin Island to Taiwan. Of the more than 3,300 islands that comprise Japan (the total number varies between 3,300 to over 3,700 according to whether they are classified as islands, islets, or mere rocks), only five are of any significant size and all are relatively narrow in width: Hokkaido, the northernmost; the long, narrow Honshu (called the "mainland"); Shikoku; Kyushu, the southernmost; and Okinawa, located in the Ryukyu Islands. Other noteworthy islands include Tsushima, which lies just north of Kyushu in the Korea Strait; the Ryukyu Islands, which extend southwest from Kyushu almost to the Chinese island of Taiwan; and the Daito Islands well south of Kyushu. Strung out to the south of Honshu in a line toward the Mariana Islands are the Izu Islands, the Bonin Islands, and the Volcano Islands, including Iwo Jima (Sulphur Island).
Situated along the Pacific Ocean's "ring of fire," Japan is a nation built by volcanoes and lives with the violent forces of creation on an almost daily basis. The now dormant volcano Mt. Fuji emerged about 10,000 years ago with the eruption of the Shin-Fuji volcano. The nearly 100 eruptions that occurred repeatedly since then and gave this mountain its photogenic conical shape ended in 1707 with the Hoei Eruption, reportedly the largest of all eruptions in the mountain's recorded history. There are over 200 known volcanoes on Japan with more than 20 still active. In July 1989 a strong underwater eruption occurred near the city of Izu, some 100 km (62 mi) southwest of Tokyo. The abundance of volcanoes has produced a beneficial side-effect: a great number of hot springs whose waters are used for medical and therapeutical purposes.
The Japanese islands sit over an extremely unstable region of the earth's crust where the Phillipine Sea Tectonic Plate and the vast Pacific Tectonic Plate subduct under the Eurasian Continental Plate and the North American Continental Plate near East Asia. Situated in the subduction zone at the boundaries of these plates, Japan has the distinction of living with more earthquakes than any other country on earth. If you include tremors detectable by only the most sensitive seismographs, about 7,500 earthquakes may occur in any given year in Japan and its surrounding areas. Of these, about 1,500 can be felt by humans. As many as 40 or 50 earthquakes felt by humans occur yearly in the Tokyo area alone.
Destructive earthquakes occur approximately once in two years somewhere or other in Japan. Because of its rocky foundation, weak or strong, near or far, earthquakes in this part of the world are capable of causing considerable damage. The Great Kanto Earthquake in September 1923, left 99,331 dead, 43,476 missing, 8,226 houses completely collapsed, 126,233 partially collapsed, and 447,128 destroyed by fire from Yokohama to Tokyo and across the surrounding countryside. It also triggered a huge landslide on Mt. Tanzawa, causing more damage to the surrounding landscape than any earthquake since historical records began. Ever-mindful of the potential for disaster, the Japanese worry about the timing of the next big earthquake, which is regarded as inevitable. With its back arched toward the vast Pacific Ocean, even an earthquake centered off the coast of South America or California can generate a giant tidal wave, tsunami, that could have disastrous consequences for Japan.
Japan's terrain is a complex mixture of geographical features. Nearly 80% of Japanese land is mountainous, with numerous small and narrow plains found mainly along the coasts. Basins are found inland, and where mountains and plains or basins meet, river fans have developed. The coastline is complex and heavily indented, with numerous bays and peninsulas. Topographically, Japan can be divided into nine geographic regions: the islands of Hokkaido, Kyushu, Shikoku, and Okinawa and on the main island of Honshu, the Tohoku, Kanto, Chubu, Kinki (or Kansai) and Chugoku regions.
Hokkaido
Japan's northern-most island covers some 78,073 sq km (30,144 sq mi) and accounts for one-fifth of the country's total land area. With the Pacific Ocean to the south, the Sea of Japan to the west, the La Perouse Strait separates Hokkaido from Russia's Sakhalin Island to the north. Across the Tsugaru Strait to the south lies the main island of Honshu.
The least populated of the main islands, Hokkaido features fertile coastal plains, extensive wet lands, natural lakes, and marshes with beautiful landscapes and a diversity of breathtaking mountain terrain often rising above 2,000m (6,562 ft). Rising from the Teshio Plain at the northern tip of the island, the Teshio Mountains form a rocky spine down the western edge of Hokkaido, ending at the Ishikari plain in the southwest. Three major basins define the center of the island: the Nayoro Basin in the north, the Kamikawa Basin in the center, and the Furano Basin in the south, out of which rise the Yubari Mountains to the southwest, the Hidaka Range to the south and the Ishikari Mountains to the southeast. Beginning just north of the Nayoro Basin, the Kitami Mountains stretch southeastward along the eastern flank of the central basins. Just east of this range in northeastern Hokkaido lies the Kitami Basin. The large Tokachi Plain lies south of the Ishikari Mountains and east of the Hidaka Range. Further east lies the Kushiro Plain.
Kyushu
The most southerly of Japan's four main islands, Kyushu covers an area of 42,023 sq km (16,225 sq mi). This irregularly-shaped and mountainous island of ancient forests, hot springs, and mysterious steaming volcanoes is separated from Honshu by the narrow Kammon Strait to the north and from Shikoku to the east by the Bungo Strait.
According to legend, Kyushu was the stage on which the gods created the Japanese Imperial lineage. Kyushu played a key role in Japan's history, serving as the initial entry point for European traders and Christianity.
Shikoku
The smallest of Japan's four main islands, Shikoku offers a breathtaking diversity of scenery across its 18,800 sq km (7,257 sq mi) of land. North of the island is the Seto Inland Sea with its hundreds of tiny islands, rich fisheries, and a coastline of citrus orchards. To the south lies the mighty Pacific Ocean. Shikoku's terrain includes high mountains, crystal clear rivers, windswept capes and ocean whirlpools. Mt. Ishizuchi, located in northwestern Shikoku, is the tallest peak in all western Japan at 1,982 m (6,499 ft).
Okinawa
Japan's southernmost prefecture, located about half-way between Kyushu and Taiwan, consists of 50 inhabited and 110 uninhabited islands scattered across approximately 400,000 sq km (154,440 sq mi) of ocean between the East China Sea and the Pacific. The prefecture includes the Miyako and Yaeyama Island groups and the Okinawa Island group, with the main island of Okinawa as the heart of the territory. Okinawa Island is by far the largest of these islands, followed by Iriomote Island, Ishigaki Island, and Miyako Island in the Yaeyama Group. The highest point on the island of Okinawa is the 505 m (1,657 ft) peak near the northeastern end of Okinawa Island. Ishigaki Island boast a single peak in the center of the island the reaches 545 m (1,789 ft).
Okinawa is the only prefecture in Japan that is truly subtropical and its volcanic islands have long been home to many unusual and beautiful species of flora and fauna. Visitors to this land find a southern paradise with Mangrove forests and waterfalls, a land where colorful flowers of the subtropics bloom year-round. Surrounded by dazzling white beaches, emerald-green seas, and magnificent coral reefs that rank among the finest in the world, the resplendent green islands of Okinawa are the jewels of the Ryukyu Island chain.
Honshu
Japan's largest island. Honshu accounts for 231,073 sq km (89,194 sq mi) of the nations land and five of its geographic regions: Tohoku, Kanto, Chubu, Kansai, and Chugoku. Honshu is predominantly mountainous surrounded by a low-lying coastal belt.
Tohoku
Located on the northeastern end of Honshu, Tohoku is a region marked by a mountainous spine that runs roughly down the center of the region. It is a landscape of rugged coastlines, breathtaking islands, bubbling hot springs, sacred volcanoes, deep ravines, thickly forested mountains, and picture-postcard lakes.
Kanto
The largest and most fertile area of level land in Japan is the Kanto Plain (which includes Tokyo), located on the Pacific coast in central Honshu, currently the political, economic, and cultural center of Japan. The Kanto Plain is one of the few truly large plains anywhere in Japan, the other notable ones being the Kansai Plain and the broad fertile Nobi Plain further south. The landscape gradually rises north from the Pacific coast to meet the high mountains of central Honshu. To the northwest and west, the terrain rises sharply to the Kanto Mountain Range.
Chubu
The Chubu region is located virtually in the center of the Japanese island chain. It is a mountainous region marked by an abundance of topographical variation and natural scenic vistas. The northern extent of this landscape is dominated by an alpine region known as the "Japanese Alps," a magnificent expanse of jagged peaks interspersed with high basins formed by the snow-capped Kiso and Hida Mountain Ranges. The peaks in this area reach elevations from 2,500 m to 3,000 m (8,200 ft to 9,840 ft), although the highest peak in the area, Mt.Okuhotaka, located in the Chubu-Sangaku National Park, reaches 3,190m (10,466 ft). Nearly 82% of this land is forested and alpine flora abounds in the warmer months. Further south are the Minami Alps, formed along the Akaishi Mountain Range. Mt. Aino dominates this area at 3,189 m (10,463 ft).
The snow-melt from this region feeds a number of streams and rivers which drain either north into the Sea of Japan or south to the Pacific. The rapid drop in terrain near the coast produces quick currents and rapids, making inland navigation virtually impossible except across the flatter coastal plains. Japan's short and fast-flowing rivers exhibit a great variation in flow from season to season. River transport, once common has become negligible with the construction of railways. Deltas develop along the lower reaches of large rivers, providing fertile ground often used for rice-growing.
Kansai
Honshu's central lowlands, located at the point where Honshu bends westward from the northeast comprise an area accentuated by alternating plains, basins, and mountains that stretch east to west from the Seto Inland Sea to Ise Bay and include both Awaji Island and Osaka Bay. Located in a high basin east of Osaka and west of Nagoya is Lake Biwa, Japan's largest fresh-water lake.
North of the central lowlands is a region consisting of plains and mountainous terrain interspersed with basins. These higher mountains range north toward the Sea of Japan to create a very rugged, zigzagging coastline.
To the south of the central lowlands, a complex of lava peaks and undulating uplands stretches westward across the Kii Peninsula, connects to mountains on Shikoku and Kyushu facing the Pacific, on to the volcanic Ryukyu archipelago which includes Okinawa then sweeps south towards Taiwan. The mountain range has somewhat sharp peaks rising nearly 2,000 m (6,560 ft) above sea level in the central part of the Kii Peninsula and the eastern part of Shikoku.
Chugoku
The Chugoku region marks the western extent Honshu. Like Tohoku in the northeast, this region is defined by the spine of the Chugoku Mountains running along its center which uplifts the landscape toward the Sea of Japan on the north and toward the Seto Inland Sea on the south.
