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Bio-duck
Bio-duck is a sound recorded in the Southern Ocean, specifically in Antarctic Waters and the West Coast of Australia. It was first reported in 1960 by submarine personnel, who gave the sound its name, associating it with that of a duck. Once dubbed as the “largest still unresolved mysteries of the Southern Ocean”, the origin of the sound remained a mystery for decades until 2014, when it was concluded that the sound originated from Antarctic Minke Whales. The recorded sound has a frequency range between 60 Hz to 100 Hz, harmonics up to 1khz, and an interval of 1.6 to 3.1 seconds between each sound. The sound is mainly present during austral winter in the southern ocean, detected off Western Australia and the Antarctic waters. The sound is made near the surface, predominantly before feeding dives. Although the role of the sound remains a mystery, it is suggested that it could play a role in mating. Researchers say that this discovery is significant in estimating sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bio-duck
Bio-duck is a sound recorded in the Southern Ocean, specifically in Antarctic Waters and the West Coast of Australia. It was first reported in 1960 by submarine personnel, who gave the sound its name, associating it with that of a duck. Once dubbed as the “largest still unresolved mysteries of the Southern Ocean”, the origin of the sound remained a mystery for decades until 2014, when it was concluded that the sound originated from Antarctic Minke Whales. The recorded sound has a frequency range between 60 Hz to 100 Hz, harmonics up to 1khz, and an interval of 1.6 to 3.1 seconds between each sound. The sound is mainly present during austral winter in the southern ocean, detected off Western Australia and the Antarctic waters. The sound is made near the surface, predominantly before feeding dives. Although the role of the sound remains a mystery, it is suggested that it could play a role in mating. Researchers say that this discovery is significant in estimating sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Minke Whale
The Antarctic minke whale or southern minke whale (''Balaenoptera bonaerensis'') is a species of minke whale within the suborder of baleen whales. It is the second smallest rorqual after the common minke whale and the third smallest baleen whale. Although first scientifically described in the mid-19th century, it was not recognized as a distinct species until the 1990s. Once ignored by the whaling industry due to its small size and low oil yield, the Antarctic minke was able to avoid the fate of other baleen whales and maintained a large population into the 21st century, numbering in the hundreds of thousands.Branch, T. A. (2006). "Abundance estimates for Antarctic minke whales from three completed circumpolar sets of surveys, 1978/79 to 2003/04". ''Paper'' SC/58/IA18 ''submitted to the International Whaling Commission Scientific Committee'', pp. 1–28. Surviving to become the most abundant baleen whale in the world, it is now one of the mainstays of the industry alongside its c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unidentified Sounds
The following is a list of unidentified, or formerly unidentified, sounds. All of the 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. Unidentified sounds The following unidentified sounds have been detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) using its Equatorial Pacific Ocean autonomous hydrophone array. 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 enough to be recorded throughout the Pacific. The sound appears to be seasonal, generally reaching peaks in sprin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-smallest of the five principal oceanic divisions: smaller than the Pacific, Atlantic, and Indian oceans but larger than the Arctic Ocean. Over the past 30 years, the Southern Ocean has been subject to rapid climate change, which has led to changes in the marine ecosystem. By way of his voyages in the 1770s, James Cook proved that waters encompassed the southern latitudes of the globe. Since then, geographers have disagreed on the Southern Ocean's northern boundary or even existence, considering the waters as various parts of the Pacific, Atlantic, and Indian oceans, instead. However, according to Commodore John Leech of the International Hydrographic Organization (IHO), recent oceanographic research has discovered the importance of Southern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black South Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and east. Although Kazungula, it does not border Zimbabwe, less than 200 metres (660 feet) of the Botswanan right bank of the Zambezi, Zambezi River separates the two countries. Namibia gained independence from South Africa on 21 March 1990, following the Namibian War of Independence. Its capital and largest city is Windhoek. Namibia is a member state of the United Nations (UN), the Southern African Development Community (SADC), the African Union (AU) and the Commonwealth of Nations. The driest country in sub-Saharan Africa, Namibia has been inhabited since pre-historic times by the San people, San, Damara people, Damara and Nama people. Around the 14th century, immigration, immigrating Bantu peoples arrived as part of the Bantu expansion. Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perth Canyon
Perth Canyon is a submarine canyon located on the edge of the continental shelf off the coast of Perth, Western Australia, approximately west of Rottnest Island. It was carved by the Swan River, probably before the Tertiary, when this part of the continental shelf was above sea level. It is an average of deep and across, making it similar in dimension to the Grand Canyon. It occupies an area of and ranges in depth from . Within a few kilometres its depth drops from down to , and then it continues as a deep gully all the way out to the depth, which is about another farther west. It contains the world's largest plunge poola depression in the canyon that is long, across, and deep. The canyon is considered "a perfect spot" for deep sea fishing. The Perth Canyon is a feeding ground for pygmy blue whales, especially at the rims of the abyss. It is also a training ground for the Royal Australian Navy Submarine Service, stationed at a naval base at nearby Garden Island. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irradiance
In radiometry, irradiance is the radiant flux ''received'' by a ''surface'' per unit area. The SI unit of irradiance is the watt per square metre (W⋅m−2). The CGS unit erg per square centimetre per second (erg⋅cm−2⋅s−1) is often used in astronomy. Irradiance is often called intensity, but this term is avoided in radiometry where such usage leads to confusion with radiant intensity. In astrophysics, irradiance is called ''radiant flux''. Spectral irradiance is the irradiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. The two forms have different dimensions and units: spectral irradiance of a frequency spectrum is measured in watts per square metre per hertz (W⋅m−2⋅Hz−1), while spectral irradiance of a wavelength spectrum is measured in watts per square metre per metre (W⋅m−3), or more commonly watts per square metre per nanometre (W⋅m−2⋅nm−1). Mathematical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krill
Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in northwestern Europe * Norwegians, both a nation and an ethnic group native to Norway * Demographics of Norway *The Norwegian language, including ... word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are considered an important trophic level connection – near the bottom of the food chain. They feed on phytoplankton and (to a lesser extent) zooplankton, yet also are the main source of food for many larger animals. In the Southern Ocean, one species, the Antarctic krill, ''Euphausia superba'', makes up an estimated biomass (ecology), biomass of around 379,000,000 tonnes, making it among the species with the largest total biomass. Over half of this biomass is eaten by whales, Pinniped, seals, pen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Sea
The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha Coast, Queen Maud Land. To the east of Cape Norvegia is the King Haakon VII Sea. Much of the southern part of the sea is covered by a permanent, massive ice shelf field, the Filchner-Ronne Ice Shelf. The sea is contained within the two overlapping Antarctic territorial claims of Argentine Antarctica, the British Antarctic Territory, and also resides partially within the Antarctic Chilean Territory. At its widest the sea is around across, and its area is around . Various ice shelves, including the Filchner-Ronne Ice Shelf, fringe the Weddell sea. Some of the ice shelves on the east side of the Antarctic Peninsula, which formerly covered roughly of the Weddell Sea, had completely disappeared by 2002. The Weddell Sea has been deemed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whale Sounds
Whales use a variety of sounds for communication and sensation. The mechanisms used to produce sound vary from one family of cetaceans to another. Marine mammals, including whales, dolphins, and porpoises, are much more dependent on sound than land mammals due to the limited effectiveness of other senses in water. Sight is less effective for marine mammals because of the particulate way in which the ocean scatters light. Smell is also limited, as molecules diffuse more slowly in water than in air, which makes smelling less effective. However, the speed of sound is roughly four times greater in water than in the atmosphere at sea level. As sea mammals are so dependent on hearing to communicate and feed, environmentalists and cetologists are concerned that they are being harmed by the increased ambient noise in the world's oceans caused by ships, sonar and marine seismic surveys. The word "song" is used to describe the pattern of regular and predictable sounds made by some spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_13.jpg "Click for more on -> Antarctic Minke Whale")
