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List Of Unexplained Sounds
The following is a list of unidentified, or formerly unidentified, sounds. All of the NOAA sound files in this article have been sped up by at least a factor of 16 to increase intelligibility by condensing them and raising the frequency from infrasound to a more audible and reproducible range. Formerly unidentified sounds NOAA The following previously unidentified sounds have been detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) using its Equatorial Pacific Ocean autonomous hydrophone array. Researchers have since posited volcanic and glacial origins for the sounds. Upsweep Upsweep is an unidentified sound detected on the American NOAA's equatorial autonomous hydrophone arrays. This sound was present when the Pacific Marine Environmental Laboratory began recording its sound surveillance system, SOSUS, in August 1991. It consists of a long train of narrow-band upsweeping sounds of several seconds in duration each. The source level is high eno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrasound
Infrasound, sometimes referred to as low frequency sound or incorrectly subsonic (subsonic being a descriptor for "less than the speed of sound"), describes sound waves with a Audio frequency, frequency below the lower limit of human audibility (generally 20 Hertz, Hz, as defined by the ANSI/ASA S1.1-2013 standard). Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. Although the ear is the primary organ for sensing low sound, at higher intensities it is possible to feel infrasound vibrations in various parts of the body. The study of such sound waves is sometimes referred to as infrasonics, covering sounds beneath 20 Hz down to 0.1 Hz (and rarely to 0.001 Hz). People use this frequency range for monitoring earthquakes and volcanoes, charting rock and petroleum formations below the earth, and also in ballistocardiography and seismocardiography to study the mechanics of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icequake
A cryoseism, ice quake or frost quake, is a seismic event caused by a sudden cracking action in frozen soil or rock saturated with water or ice, or by stresses generated at frozen lakes. As water drains into the ground, it may eventually freeze and expand under colder temperatures, putting stress on its surroundings. This stress builds up until relieved explosively in the form of a cryoseism. The requirements for a cryoseism to occur are numerous; therefore, accurate predictions are not entirely possible and may constitute a factor in structural design and engineering when constructing in an area historically known for such events. Speculation has been made between global warming and the frequency of cryoseisms. Effects Cryoseisms are often mistaken for minor intraplate earthquakes. Initial indications may appear similar to those of an earthquake with tremors, vibrations, ground cracking and related noises, such as thundering or booming sounds. Cryoseisms can, however, be d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryogenics
In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th International Institute of Refrigeration's (IIR) International Congress of Refrigeration (held in Washington, DC in 1971) endorsed a universal definition of "cryogenics" and "cryogenic" by accepting a threshold of to distinguish these terms from conventional refrigeration. This is a logical dividing line, since the normal boiling points of the so-called permanent gases (such as helium, hydrogen, neon, nitrogen, oxygen, and normal air) lie below 120 K, while the Freon refrigerants, hydrocarbons, and other common refrigerants have boiling points above 120 K. Discovery of superconducting materials with critical temperatures significantly above the boiling point of nitrogen has provided new interest in reliable, low-cost methods of producing high-temperature cryogenic refrigeration. The term "high temperature cryogenic" describes temperatures ranging from above the boili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Adare
Cape Adare is a prominent cape of black basalt forming the northern tip of the Adare Peninsula and the north-easternmost extremity of Victoria Land, East Antarctica. It is the site of the first confirmed landing on the Antarctic mainland—undertaken from ''Antarctic'' in 1895—and the first base on the Antarctic mainland—established by ''Southern Cross'' in 1899. On both occasions an important role was played by Carstens Borchgrevink. Description Marking the north end of Borchgrevink Coast and the west end of Pennell Coast, the cape separates the Ross Sea to the east from the Southern Ocean to the west, and is backed by the high Admiralty Mountains. Cape Adare was an important landing site and base camp during early Antarctic exploration. Off the coast to the northeast are the Adare Seamounts and the Adare Trough. History Captain James Ross discovered Cape Adare in January 1841 and named it after his friend the Viscount Adare (the title is derived from A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross Sea
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of . The circulation of the Ross Sea is dominated by a wind-driven ocean gyre and the flow is strongly influenced by three submarine ridges that run from southwest to northeast. The circumpolar deep water current is a relatively warm, salty and nutrient-rich water mass that flows onto the continental shelf at certain locations. The Ross Sea is covered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bransfield Strait
Bransfield Strait or Fleet Sea () is a body of water about wide extending for in a general northeast – southwest direction between the South Shetland Islands and the Antarctic Peninsula. History The strait was named in about 1825 by James Weddell, Master, Royal Navy, for Edward Bransfield, Master, RN, who charted the South Shetland Islands in 1820. It is called ''Mar de la Flota'' by Argentina. On 23 November 2007, the MS ''Explorer'' struck an iceberg and sank in the strait; all 154 passengers were rescued and no injuries were reported. Description The undersea trough through the strait is known as Bransfield Trough (). The basin is about 400 km long and 2 km deep, between the South Shetland Island Arc and the Antarctic Peninsula. It was formed by rifting behind the islands, which began about 4 million years ago. Ongoing rifting has caused recent earthquakes and volcanism. The Strait hosts a chain of submerged seamounts of volcanic origin, including the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Georgia Island
South Georgia is an island in the Atlantic Ocean, South Atlantic Ocean that is part of the British Overseas Territories, British Overseas Territory of South Georgia and the South Sandwich Islands. It lies around east of the Falkland Islands. Stretching in the east–west direction, South Georgia is around long and has a maximum width of . The terrain is mountainous, with the central ridge rising to at Mount Paget. The northern coast is indented with numerous bays and fjords, serving as harbor, harbours. Discovered by Europeans in 1675, South Georgia had no indigenous population due to its harsh climate and remoteness. Captain James Cook in made the first landing, survey and mapping of the island. On 17 January 1775, Cook claimed it a British possession, naming it "Isle of Georgia" after George III, King George III. Through its history of South Georgia and the South Sandwich Islands, history, it served as a whaling and seal hunting base, with intermittent population scattere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryoseism
A cryoseism, ice quake or frost quake, is a seismic event caused by a sudden cracking action in frozen soil or rock saturated with water or ice, or by stresses generated at frozen lakes. As water drains into the ground, it may eventually freeze and expand under colder temperatures, putting stress on its surroundings. This stress builds up until relieved explosively in the form of a cryoseism. The requirements for a cryoseism to occur are numerous; therefore, accurate predictions are not entirely possible and may constitute a factor in structural design and engineering when constructing in an area historically known for such events. Speculation has been made between global warming and the frequency of cryoseisms. Effects Cryoseisms are often mistaken for minor intraplate earthquakes. Initial indications may appear similar to those of an earthquake with tremors, vibrations, ground cracking and related noises, such as thundering or booming sounds. Cryoseisms can, however, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue Whale
The blue whale (''Balaenoptera musculus'') is a marine mammal and a baleen whale. Reaching a maximum confirmed length of and weighing up to , it is the largest animal known ever to have existed. The blue whale's long and slender body can be of various shades of greyish-blue on its upper surface and somewhat lighter underneath. Four subspecies are recognized: ''B. m. musculus'' in the North Atlantic and North Pacific, ''B. m. intermedia'' in the Southern Ocean, ''B. m. brevicauda'' (the pygmy blue whale) in the Indian Ocean and South Pacific Ocean, and ''B. m. indica'' in the Northern Indian Ocean. There is a population in the waters off Chile that may constitute a fifth subspecies. In general, blue whale populations migrate between their summer feeding areas near the poles and their winter breeding grounds near the tropics. There is also evidence of year-round residencies, and partial or age/sex-based migration. Blue whales are filter feeders; their diet consists almost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bomb
A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven projectiles, pressure damage, and explosion-generated effects. Bombs have been utilized since the 11th century starting in East Asia. The term ''bomb'' is not usually applied to explosive devices used for civilian purposes such as construction or mining, although the people using the devices may sometimes refer to them as a "bomb". The military use of the term "bomb", or more specifically aerial bomb action, typically refers to airdropped, unpowered explosive weapons most commonly used by air forces and naval aviation. Other military explosive weapons not classified as "bombs" include shells, depth charges (used in water), or land mines. In unconventional warfare, other names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine
A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or informally to refer to remotely operated vehicles and Autonomous underwater vehicle, robots, or to medium-sized or smaller vessels (such as the midget submarine and the wet sub). Submarines are referred to as ''boats'' rather than ''ships'' regardless of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and submarines were adopted by several navies. They were first used widely during World War I (1914–1918), and are now used in many navy, navies, large and small. Their military uses include: attacking enemy surface ships (merchant and military) or other submarines; aircraft carrier protection; Blockade runner, blockade running; Ballistic missile submarine, nuclear deterrenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
