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Hii River
The is a river on the island of Honshu in Shimane Prefecture and Tottori Prefecture, Japan. With a length of 153 km and catchment of 2540 km2, it is the largest river in the east of Shimane Prefecture. It flows through the cities of Izumo and Matsue and through the lakes Shinji and Nakaumi and discharges into the Sea of Japan. In the antiquity the river was known as "Izumo-no-okawa" (出雲大川, "The great Izumo river"). The River Hii significantly changed its course and transformed the land several times during last 7 millennia. Alluvial deposits carried by the river joined the Shimane peninsula to the mainland, which may have been represented in the "Kunibiki-shinwa" myth. Since the 17th century it flows into lake Shinji, and since the early 20th century continues to the Sea of Japan. Hii river frequently caused floods in its catchment. On the other hand, it was and currently is an important source of drinking and irrigation water. During the Edo period the upper Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Glacial Maximum
The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Europe, and Asia and profoundly affected Earth's climate by causing drought, desertification, and a large drop in sea levels. Based on changes in position of ice sheet margins dated via terrestrial cosmogenic nuclides and radiocarbon dating, growth of ice sheets commenced 33,000 years ago and maximum coverage was between 26,500 years and 19–20,000 years ago, when deglaciation commenced in the Northern Hemisphere, causing an abrupt rise in sea level. Decline of the West Antarctica ice sheet occurred between 14,000 and 15,000 years ago, consistent with evidence for another abrupt rise in the sea level about 14,500 years ago. Glacier fluctuations around the Strait of Magellan suggest the peak in glacial surface area was constrained to betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemical Oxygen Demand
Biochemical oxygen demand (BOD) is the amount of dissolved oxygen (DO) needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at a certain temperature over a specific time period. The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and is often used as a surrogate of the degree of organic pollution of water. BOD reduction is used as a gauge of the effectiveness of wastewater treatment plants. BOD of wastewater effluents is used to indicate the short-term impact on the oxygen levels of the receiving water. BOD analysis is similar in function to chemical oxygen demand (COD) analysis, in that both measure the amount of organic compounds in water. However, COD analysis is less specific, since it measures everything that can be chemically oxidized, rather than just levels of biologically oxidized organic matter. Background Most natu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical ero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tatara (furnace)
The is the traditional Japanese furnace used for smelting iron and steel. The word later also came to mean the entire building housing the furnace. The traditional steel in Japan comes from ironsand processed in a special way, called tatara system.https://www.jsme.or.jp/tsd/ICBTT/conference02/TatsuoINOUE.html "Science of Tatara and Japanese Sword - Traditional Technology viewed from Modern Science" by Tatsuo INOUE Iron ore was used in the first steel manufacturing in Japan. Tatara steelmaking process using ironsand was conducted in the Kibi Province, which later became the base of the Bizen school of swordsmithing, around the middle of the sixth century, and steelmaking using ironsand is thought to have spread from Kibi to various places in Japan. In western Japan, a low box-shaped furnace different from the Chinese and Korean style was used to refine iron, and in eastern Japan, both a low box-shaped furnace and a vertical furnace unique to Japan were used. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ironsand
Ironsand, also known as iron-sand or iron sand, is a type of sand with heavy concentrations of iron. It is typically dark grey or blackish in colour. It is composed mainly of magnetite, Fe3O4, and also contains small amounts of titanium, silica, manganese, calcium and vanadium. Ironsand has a tendency to heat up in direct sunlight, causing temperatures high enough to cause minor burns. As such it forms a hazard in New Zealand at popular west-coast surf beaches such as Piha. Occurrence Ironsand is found worldwide. Although the iron mineral composition of the ironsand is mostly magnetite, the sand is usually mixed with other types of sand that washes downriver or ashore from mountainous or underwater deposits. The exact composition of the sand mixture may vary drastically even in the same geographic region. In some areas the sand may contain mostly quartz, while in others the sand may be made primarily from volcanic rock such as basalt, depending on the types of minerals alo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamata No Orochi
, or simply , is a legendary eight-headed and eight-tailed Japanese dragon/ serpent. Mythology Yamata no Orochi legends are originally recorded in two ancient texts about Japanese mythology and history. The 712 AD transcribes this dragon name as and the 720 AD writes it as . In both versions of the Orochi myth, the Shinto storm god Susanoo (or "Susa-no-O") is expelled from Heaven for tricking his sister Amaterasu, the sun goddess. After expulsion from Heaven, Susanoo encounters two near the head of the , now called the , in Izumo Province. They are weeping because they were forced to give the Orochi one of their daughters every year for seven years, and now they must sacrifice their eighth, , who Susanoo transforms into a for safekeeping. The tells the following version: The also describes Yamata no Orochi: "It had an eight-forked head and an eight-forked tail; its eyes were red, like the winter-cherry; and on its back firs and cypresses were growing. As it craw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Susanoo-no-Mikoto
__FORCETOC__ Susanoo (; historical orthography: , ) is a in Japanese mythology. The younger brother of Amaterasu, goddess of the sun and mythical ancestress of the Japanese imperial line, he is a multifaceted deity with contradictory characteristics (both good and bad), being portrayed in various stories either as a wild, impetuous god associated with the sea and storms, as a heroic figure who killed a monstrous serpent, or as a local deity linked with the harvest and agriculture. Syncretic beliefs that arose after the introduction of Buddhism to Japan also saw Susanoo becoming conflated with deities of pestilence and disease. Susanoo, alongside Amaterasu and the earthly Ōkuninushi (also Ōnamuchi) – depicted as either Susanoo's son or scion depending on the source – is one of the central deities of the imperial Japanese mythological cycle recorded in the ( CE) and the (720 CE). One of the gazetteer reports () commissioned by the imperial court during the same per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Izumo Taisha
, officially Izumo Ōyashiro, is one of the most ancient and important Shinto shrines in Japan. No record gives the date of establishment. Located in Izumo, Shimane Prefecture, it is home to two major festivals. It is dedicated to the god , famous as the Shinto deity of marriage and to Kotoamatsukami, distinguishing heavenly ''kami''. The shrine is believed by many to be the oldest Shinto shrine in Japan, even predating the Ise Grand Shrine. A style of architecture, ''taisha-zukuri'', takes its name from the main hall of Izumo-taisha. That hall, and the attached buildings, were designated National Treasures of Japan in 1952. According to tradition, the hall was previously much taller than at present. The discovery in the year 2000 of the remains of enormous pillars has lent credence to this. The shrine has been rebuilt every 60 to 70 years to maintain the power of the ''kami'' and maintain architectural techniques. This regular rebuilding process is called "Sengū" (遷宮 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silla
Silla or Shilla (57 BCE – 935 CE) ( , Old Korean: Syera, Old Japanese: Siraki2) was a Korean kingdom located on the southern and central parts of the Korean Peninsula. Silla, along with Baekje and Goguryeo, formed the Three Kingdoms of Korea. Founded by Hyeokgeose of Silla, of the Park family, the Korean dynasty was ruled by the Gyeongju Gim (Kim) (김, 金) clan for 586 years, the Miryang Bak (Park) (박, 朴) clan for 232 years and the Wolseong Seok (석, 昔) clan for 172 years. It began as a chiefdom in the Samhan confederacies, once allied with Sui China and then Tang China, until it eventually conquered the other two kingdoms, Baekje in 660 and Goguryeo in 668. Thereafter, Unified Silla occupied most of the Korean Peninsula, while the northern part re-emerged as Balhae, a successor-state of Goguryeo. After nearly 1,000 years of rule, Silla fragmented into the brief Later Three Kingdoms of Silla, Later Baekje, and Taebong, handing over power to Goryeo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of but is capable of reaching speeds up to . The gases and tephra can reach temperatures of about . Pyroclastic flows are the most deadly of all volcanic hazards and are produced as a result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Origin of term The word ''pyroclast'' is derived from the Greek (''pýr''), meaning "fire", and (''klastós''), meaning "broken in pieces". A name for pyroclastic flows which glow red in the dark is (French, "burning cloud"); this was notably used to describe the disastrous 1902 eruption of Mount Pelée on Martinique, a Fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone ( sedimentary rocks) through lithification. Sediments are most often transported by water ( fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments. Classification Sediment can be classified based on its grain size, grain s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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