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Myōjin-shō
is a submarine volcano located about 450 kilometers south of Tokyo on the Izu-Ogasawara Ridge in the Izu Islands. Volcanic activity has been detected there since 1869. Since then it has undergone more eruptions, the most powerful of which resulted in the appearance and disappearance of a small island. The name Myōjin-shō derives from a fishing boat, ''No.11 Myōjin-Maru'' of Yaizu City, Shizuoka Prefecture, the crew of which first witnessed the major volcanic eruption of 1952. Eruption of 1952-1953 The volcanic eruption from 1952 to 1953 was one of its biggest eruptions on record, with the repetitious appearance and disappearance of an island, which at one point reached over ten metres above sea level, before sinking after a major volcanic eruption in September 1953. On September 24, 1952, a survey vessel, ''Kaiyo Maru No. 5'' of the Hydrographic Department of the Maritime Safety Agency, was destroyed by the volcano, with the loss of its crew of 31 (including the nine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Izu Islands
The are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshū, Japan. Administratively, they form two towns and six villages; all part of Tokyo Prefecture. The largest is Izu Ōshima, usually called simply Ōshima. Although usually called the " Seven Islands of Izu" ( 伊豆七島 in Japanese), there are in fact more than a dozen islands and islets. Nine among them are currently inhabited. Geography The Izu islands stretch south-east from the Izu Peninsula on Honshu and cover an area of approximately . There are nine populated islands with a total population of 24,645 people () spread over . The largest of them is Izu Oshima (8,346 inhabitants, ), the smallest Toshima (292 inhabitants, .) Of the inhabited islands, seven are traditionally referred to as the "Izu Seven": Oshima, Toshima, Niijima, Kozujima, Miyakejima, Hachijojima, and Mikurajima, though Shikinejima and Aogashima are sometimes included as well. Each of the islands has its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayonnaise Rocks
is a group of volcanic rocks in the Philippine Sea about south of Tokyo and south-southeast of Aogashima, in the south portion of the Izu archipelago, Japan. The rocks were discovered by the French corvette ''Bayonnaise'' in 1850, while surveying the islands south of Tokyo Bay. Geography The rocks are the exposed portion of the western ridge of a submarine volcanic caldera, approximately in diameter at a depth of approximately .Christopher G. Newhall, Daniel Dzurisin: ''Historical Unrest at large Calderas of the World.'' Volume 1, U.S. Geological Survey Bulletin 1855, Washington 1988, p. 506Bathymetric map around "Bayonnaise Rocks" based on Basic Map of the Sea(1:50.000, retrieved 2012-12-13). The above sea-level portion has a surface area of approximately 0.01 square kilometers, with a summit height of . and consists of three large rocks and many smaller rocks. The caldera is known to have erupted in 1869–1871, 1896, 1906, 1915, 1934, 1946, 1952–1955, 1957–1960, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SOFAR Channel
The SOFAR channel (short for sound fixing and ranging channel), or deep sound channel (DSC), is a horizontal layer of water in the ocean at which depth the speed of sound is at its minimum. The SOFAR channel acts as a waveguide for sound, and low frequency sound waves within the channel may travel thousands of miles before dissipating. An example was reception of coded signals generated by the Navy chartered ocean surveillance vessel ''Cory Chouest'' off Heard Island, located in the southern Indian Ocean (between Africa, Australia and Antarctica), by hydrophones in portions of all five major ocean basins and as distant as the North Atlantic and North Pacific.Figure 1 of the referenc"The Heard Island Feasibility Test"(Munk) shows ray paths to receiving locations. Table 1 lists the sites with one being a Canadian research vessel with a towed array off Cape Cod. This phenomenon is an important factor in ocean surveillance. The deep sound channel was discovered and described independ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1952 Natural Disasters
Year 195 ( CXCV) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Scrapula and Clemens (or, less frequently, year 948 ''Ab urbe condita''). The denomination 195 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Emperor Septimius Severus has the Roman Senate deify the previous emperor Commodus, in an attempt to gain favor with the family of Marcus Aurelius. * King Vologases V and other eastern princes support the claims of Pescennius Niger. The Roman province of Mesopotamia rises in revolt with Parthian support. Severus marches to Mesopotamia to battle the Parthians. * The Roman province of Syria is divided and the role of Antioch is diminished. The Romans annexed the Syrian cities of Edessa and Nisibis. Severus re-establish his head ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Disasters In Japan
Japan is the country that is most affected by natural disasters mainly due to it being in the Ring of Fire. Two out of the five most expensive natural disasters in recent history have occurred in Japan, in 1995 and 2011, costing $181 billion. Japan has also been the site of some of the 10 worst natural disasters of the 21st century. Many types of natural disasters occur in Japan such as tsunamis, floods, typhoons, earthquakes, cyclones, and even volcanic eruptions. The country has gone through thousands of years of natural disasters, affecting its economy, development, and social life. Some other major disasters in Japan were more recent, such as the January 1995 Great Hanshin earthquake and the March 2011 Tōhoku earthquake and tsunami, which triggered the Fukushima Daiichi nuclear disaster. Volcanic eruptions Many volcanic eruptions have taken place in Japan. List of major volcanic eruptions VEI-7 Volcanic eruptions There are three VEI-7 volcanoes in Japan. These are the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ephemeral Islands
Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, from digital media to types of streams. "There is no single definition of ephemerality". With respect to unique performances, for example, it has been noted that " hemerality is a quality caused by the ebb and flow of the crowd's concentration on the performance and a reflection of the nostalgic character of specific performances". Because different people may value the passage of time differently, ephemerality may be a relative, perceptual concept: "In brief, what is short-lived may not be the object itself, but the attention we afford it".Ronald Beiner, ''Political Philosophy: What It Is and Why It Matters'' (2014), p. 10. Ephemerality and nature Geographical features An ephemeral stream is that which only exists following precipitation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seamounts Of The Pacific Ocean
A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to in height. They are defined by oceanographers as independent features that rise to at least above the seafloor, characteristically of conical form.IHO, 2008. Standardization of Undersea Feature Names: Guidelines Proposal form Terminology, 4th ed. International Hydrographic Organization and Intergovernmental Oceanographic Commission, Monaco. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somma Volcano
A somma volcano (also known as a sommian) is a volcano, volcanic caldera that has been partially filled by a new central volcanic cone, cone. The name comes from Mount Somma, a stratovolcano in southern Italy with a summit caldera in which the upper cone of Mount Vesuvius has grown. A number of Earth's best examples of somma volcanoes are found on Russia's Kamchatka Peninsula and the Kuril Islands that stretch south from Kamchatka to Hokkaidō (Japan). Some examples of somma volcanoes are the following: * Africa ** Pico do Fogo (Fogo, Cape Verde, Fogo Island, Cape Verde) ** Teide (Tenerife, Canary Islands, Spain) * Americas ** Cosigüina (Chinandega, Nicaragua) ** Wizard Island (Oregon, United States) ** Lava domes (Mount St. Helens, Washington (state), Washington, United States) * Asia ** Ebeko (Paramushir Island, Kuril Islands, Russia) ** Gunung Baru Jari (Segara Anak caldera, Lombok, Indonesia) ** Kolokol Group: Kolokol, Berg, Borzov, Trezubetz (Urup Island, Kuril Islands, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today the international nautical mile is defined as exactly . The derived unit of speed is the knot, one nautical mile per hour. Unit symbol There is no single internationally agreed symbol, with several symbols in use. * M is used as the abbreviation for the nautical mile by the International Hydrographic Organization. * NM is used by the International Civil Aviation Organization. * nmi is used by the Institute of Electrical and Electronics Engineers and the United States Government Publishing Office. * nm is a non-standard abbreviation used in many maritime applications and texts, including U.S. Government Coast Pilots and Sailing Directions. It conflicts with the SI symbol for nanometre. History The word mile is from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabed Topography
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of the ocean is very deep, where the seabed is known as the abyssal plain. Seafloor spreading creates mid-ocean ridges along the center line of major ocean basins, where the seabed is slightly shallower than the surrounding abyssal plain. From the abyssal plain, the seabed slopes upward toward the continents and becomes, in order from deep to shallow, the continental rise, slope, and shelf. The depth within the seabed itself, such as the depth down through a sediment core, is known as the “depth below seafloor.” The ecological environment of the seabed and the deepest waters are collectively known, as a habitat for creatures, as the “benthos.” Most of the seabed throughout the world's oceans is covered in layers of marine sediments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrography
Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection. History The origins of hydrography lay in the making of charts to aid navigation, by individual mariners as they navigated into new waters. These were usually the private property, even closely held secrets, of individuals who used them for commercial or military advantage. As transoceanic trade and exploration increased, hydrographic surveys started to be carried out as an exercise in their own right, and the commissioning of surveys was increasingly done by governments and special hydrographic offices. National organizations, particularly navies, realized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
