|
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] |
Submarine Canyon
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km, from canyon floor to canyon rim, as with the Great Bahama Canyon. Just as above-sea-level canyons serve as channels for the flow of water across land, submarine canyons serve as channels for the flow of turbidity currents across the seafloor. Turbidity currents are flows of dense, sediment laden waters that are supplied by rivers, or generated on the seabed by storms, submarine landslides, earthquakes, and other soil disturbances. Turbidity currents travel down slope at great speed (as much as 70 km/h), eroding the continental slope and finally depositing sediment onto the abyssal plain, where the particles settle out.Continental Margin Sedimentation: From Sediment Transport to Sequence Stratigraphy (Special Publication 37 of the IAS) Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Shelf
A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island is known as an ''insular shelf''. The continental margin, between the continental shelf and the abyssal plain, comprises a steep continental slope, surrounded by the flatter continental rise, in which sediment from the continent above cascades down the slope and accumulates as a pile of sediment at the base of the slope. Extending as far as 500 km (310 mi) from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. The continental rise's gradient is intermediate between the gradients of the slope and the shelf. Under the United Nations Convention on the Law of the Sea, the name continental shelf was given a legal definition as the stretch of the seabed adjacent to the shores of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is part of the South West Land Division of Western Australia, with most of the metropolitan area on the Swan Coastal Plain between the Indian Ocean and the Darling Scarp. The city has expanded outward from the original British settlements on the Swan River, upon which the city's central business district and port of Fremantle are situated. Perth is located on the traditional lands of the Whadjuk Noongar people, where Aboriginal Australians have lived for at least 45,000 years. Captain James Stirling founded Perth in 1829 as the administrative centre of the Swan River Colony. It was named after the city of Perth in Scotland, due to the influence of Stirling's patron Sir George Murray, who had connections with the area. It gained ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rottnest Island
Rottnest Island ( nys, Wadjemup), often colloquially referred to as "Rotto", is a island off the coast of Western Australia, located west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, Rottnest is an A-class reserve, the highest level of protection afforded to public land. Together with Garden Island, Rottnest Island is a remnant of Pleistocene dune ridges. Along with several other islands, Rottnest became separated from the mainland around 7,000 years ago, when sea levels rose; the traditional Noongar name for the island is ''Wadjemup'', which means "place across the water where the spirits are". Human artefacts have been found on the island dating back at least 30,000 years, but visitation and habitation of the island by the Noongar people appears to have ceased following its separation from the mainland. The island was first documented by Willem de Vlamingh in 1696, who called it t Eylandt 't Rottenest'' ("Rats' Nest Island") after the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swan River (Western Australia)
The Swan River () is a river in the south west of Western Australia. The river runs through the metropolitan area of Perth, Western Australia's capital and largest city. Course of river The Swan River estuary flows through the city of Perth. Its lower reaches are relatively wide and deep, with few constrictions, while the upper reaches are usually quite narrow and shallow. The Swan River drains the Avon and coastal plain catchments, which have a total area of about . It has three major tributaries, the Avon River, Canning River and Helena River. The latter two have dams (Canning Dam and Mundaring Weir) which provide a sizeable part of the potable water requirements for Perth and the regions surrounding. The Avon River contributes the majority of the freshwater flow. The climate of the catchment is Mediterranean, with mild wet winters, hot dry summers, and the associated highly seasonal rainfall and flow regime. The Avon rises near Yealering, southeast of Perth: it mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tertiary
Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start of the Cenozoic Era, and extended to the beginning of the Quaternary glaciation at the end of the Pliocene Epoch. The time span covered by the Tertiary has no exact equivalent in the current geologic time system, but it is essentially the merged Paleogene and Neogene periods, which are informally called the Early Tertiary and the Late Tertiary, respectively. The Tertiary established the Antarctic as an icy island continent. Historical use of the term The term Tertiary was first used by Giovanni Arduino during the mid-18th century. He classified geologic time into primitive (or primary), secondary, and tertiary periods based on observations of geology in Northern Italy. Later a fourth period, the Quaternary, was applied. In the ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Canyon
The Grand Canyon (, yuf-x-yav, Wi:kaʼi:la, , Southern Paiute language: Paxa’uipi, ) is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is long, up to wide and attains a depth of over a mile (). The canyon and adjacent rim are contained within Grand Canyon National Park, the Kaibab National Forest, Grand Canyon–Parashant National Monument, the Hualapai Indian Reservation, the Havasupai Indian Reservation and the Navajo Nation. President Theodore Roosevelt was a major proponent of the preservation of the Grand Canyon area and visited it on numerous occasions to hunt and enjoy the scenery. Nearly two billion years of Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sense Of Place
The term sense of place has been used in many different ways. It is a multidimensional, complex construct used to characterize the relationship between people and spatial settings. It is a characteristic that some geographic places have and some do not, while to others it is a feeling or perception held by people (not by the place itself). It is often used in relation to those characteristics that make a place special or unique, as well as to those that foster a sense of authentic human attachment and belonging. Others, such as geographer Yi-Fu Tuan, have pointed to senses of place that are not "positive," such as fear. Some students and educators engage in " place-based education" in order to improve their "sense(s) of place," as well as to use various aspects of place as educational tools in general. The term is used in urban and rural studies in relation to place-making and place-attachment of communities to their environment or homeland. The term sense of place is used to de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plunge Pool
A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It is created by the erosional forces of cascading water on the rocks at formation's base where the water impacts.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. The term may refer to the water occupying the depression, or the depression itself. Formation Plunge pools are formed by the natural force of falling water, such as at a waterfall or cascade; they also result from man-made structures such as some spillway designs. Plunge pools are often very deep, generally related to the height of fall, the volume of water, the resistance of the rock below the pool and other factors. The impacting and swirling water, sometimes carrying rocks within it, abrades the riverbed into a basin, which often features rough and irregular sides. Plunge pools can remain long after the waterfall has ceased flow or the stream has been d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygmy Blue Whale
The pygmy blue whale (''Balaenoptera musculus brevicauda'') is a subspecies of the blue whale (''Balaenoptera musculus'') found in the Indian Ocean and the southern Pacific Ocean. Reaching lengths of up to 24 metres (79 ft) it is smaller than the other commonly recognized subspecies, ''B. m. musculus'' and ''B. m. intermedia'', the former reaching 28 m (92 ft) and the latter 30 m (98 ft), hence its common name. The pygmy blue whale is the only one of the three identifiable subspecies to be found regularly in tropical waters. It occurs from the sub-Antarctic zone to the southern Indian Ocean and southwestern Pacific Ocean, breeding in the Indian and South Atlantic oceans, and travelling south to above the Antarctic to feed, although they very rarely cross the Antarctic Convergence. A fourth subspecies, ''B. m. indica'', was identified by Blyth in 1859 in the northern Indian Ocean, but difficulties in identifying distinguishing features for this subs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Australian Navy Submarine Service
The Royal Australian Navy Submarine Service is the submarine element of the Royal Australian Navy. The service currently forms the Navy's Submarine Force Element Group (FEG) and consists of six ''Collins'' class submarines. The Royal Australian Navy Submarine Service has been established four times, with the initial three attempts being foiled by combat losses and Australia's economic problems. The modern Submarine Service was established in 1964, and has formed an important element of the Australian military's capacity since that date. While the Submarine Service has not seen combat since World War I, Australian submarines have conducted extensive surveillance operations throughout South East Asia. The current Director General Submarines is Commodore T.A. Brown, RAN. History The Royal Australian Navy's submarine service has been established four times since 1914. 1914 to 1945 After the formation of the navy upon Federation, a period of uncertainty had followed as the size ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garden Island (Western Australia)
Garden Island (Noongar: ''Meandup'' or ''Meeandip'') is a narrow island about long and wide, lying about off the Western Australian coast, to which it is linked by an artificial causeway and bridge. Like Rottnest Island and Carnac Island, it is a limestone outcrop covered by a thin layer of sand accumulated during an era of lowered sea levels. The Noongar peoples tell of walking to these islands in their Dreamtime. At the end of the last glacial period, the sea level rose, cutting the island off from the mainland. For the last seven thousand years, the island has existed in relative isolation. The Royal Australian Navy's largest fleet base, Fleet Base West, also called HMAS ''Stirling'', is on the shores of Careening Bay, on the southeastern section of Garden Island, facing Cockburn Sound. people lived on the Garden Island base. The entirety of Garden Island is included on the Commonwealth Heritage List for its natural values. Garden Island is home to a tammar wallaby ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Royal Australian Navy Submarine Service")
