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Triangulation Station
A triangulation station, also known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon, or trig point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity. The nomenclature varies regionally: they are generally known as trigonometrical or triangulation stations in North America, trig points in the United Kingdom, trig pillars in Ireland, trig stations or points in Australia and New Zealand, and trig beacons in South Africa; triangulation pillar is the more formal term for the concrete columns found in the UK.
  • 1.5K
  • 02 Dec 2022
Topic Review
List of Highest Mountains on Earth
There are at least 108 mountains on Earth with elevations of 7,200 metres (23,622 ft) or greater above sea level. The vast majority of these mountains are located on the edge of the Indian and Eurasian plate- namely, in China , Pakistan , Nepal and India .
  • 1.4K
  • 10 Nov 2022
Topic Review
Dilophosaurus
Dilophosaurus (/daɪˌloʊfəˈsɔːrəs, -foʊ-/ dy-LOH-fə-SOR-əs, -⁠foh-) is a genus of theropod dinosaurs that lived in what is now North America during the Early Jurassic, about 193 million years ago. Three skeletons were discovered in northern Arizona in 1940, and the two best preserved were collected in 1942. The most complete specimen became the holotype of a new species in the genus Megalosaurus, named M. wetherilli by Samuel P. Welles in 1954. Welles found a larger skeleton belonging to the same species in 1964. Realizing it bore crests on its skull, he assigned the species to the new genus Dilophosaurus in 1970, as Dilophosaurus wetherilli. The genus name means "two-crested lizard", and the species name honors John Wetherill, a Navajo councilor. Further specimens have since been found, including an infant. Footprints have also been attributed to the animal, including resting traces. Another species, Dilophosaurus sinensis from China, was named in 1993, but was later found to belong to the genus Sinosaurus. At about 7 m (23 ft) in length, with a weight of about 400 kg (880 lb), Dilophosaurus was one of the earliest large predatory dinosaurs and the largest known land-animal in North America at the time. It was slender and lightly built, and the skull was proportionally large, but delicate. The snout was narrow, and the upper jaw had a gap or kink below the nostril. It had a pair of longitudinal, arched crests on its skull; their complete shape is unknown, but they were probably enlarged by keratin. The mandible was slender and delicate at the front, but deep at the back. The teeth were long, curved, thin, and compressed sideways. Those in the lower jaw were much smaller than those of the upper jaw. Most of the teeth had serrations at their front and back edges. The neck was long, and its vertebrae were hollow, and very light. The arms were powerful, with a long and slender upper arm bone. The hands had four fingers; the first was short but strong and bore a large claw, the two following fingers were longer and slenderer with smaller claws; the fourth was vestigial. The thigh bone was massive, the feet were stout, and the toes bore large claws. Dilophosaurus is a member of the family Dilophosauridae along with Dracovenator, a group placed between the Coelophysidae and later theropods. Dilophosaurus would have been active and bipedal, and may have hunted large animals; it could also have fed on smaller animals and fish. Due to the limited range of movement and shortness of the forelimbs, the mouth may instead have made first contact with prey. The function of the crests is unknown; they were too weak for battle, but may have been used in visual display, such as species recognition and sexual selection. It may have grown rapidly, attaining a growth rate of 30 to 35 kg (66 to 77 lb) per year early in life. The holotype specimen had multiple paleopathologies, including healed injuries and signs of a developmental anomaly. Dilophosaurus is known from the Kayenta Formation, and lived alongside dinosaurs such as Megapnosaurus and Sarahsaurus. Dilophosaurus was featured in the novel Jurassic Park and its movie adaptation, wherein it was given the fictional abilities to spit venom and expand a neck frill, as well as being smaller than the real animal. It was designated as the state dinosaur of Connecticut based on tracks found there.
  • 1.2K
  • 18 Oct 2022
Topic Review
Eurypterus
Eurypterus (/jʊəˈrɪptərəs/ yoo-RIP-tər-əs) is an extinct genus of eurypterid, a group of organisms commonly called "sea scorpions". The genus lived during the Silurian period, from around 432 to 418 million years ago. Eurypterus is by far the most well-studied and well-known eurypterid. Eurypterus fossil specimens probably represent more than 95% of all known eurypterid specimens. There are fifteen species belonging to the genus Eurypterus, the most common of which is E. remipes, the first eurypterid fossil discovered and the state fossil of New York. Members of Eurypterus averaged at about 13 to 23 cm (5 to 9 in) in length, but the largest individual discovered was estimated to be 60 cm (24 in) long. They all possessed spine-bearing appendages and a large paddle they used for swimming. They were generalist species, equally likely to engage in predation or scavenging.
  • 1.1K
  • 09 Nov 2022
Topic Review
3D City Models
3D city models are digital models of urban areas that represent terrain surfaces, sites, buildings, vegetation, infrastructure and landscape elements in three-dimensional scale as well as related objects (e.g., city furniture) belonging to urban areas. Their components are described and represented by corresponding two-dimensional and three-dimensional spatial data and geo-referenced data. 3D city models support presentation, exploration, analysis, and management tasks in a large number of different application domains. In particular, 3D city models allow "for visually integrating heterogeneous geoinformation within a single framework and, therefore, create and manage complex urban information spaces."
  • 1.1K
  • 04 Nov 2022
Topic Review
Weddell Island
Weddell Island (Spanish: Isla San José) is one of the Falkland Islands in the South Atlantic, lying off the southwest extremity of West Falkland. It is situated 1,545 km (960 mi) west-northwest of South Georgia Island, 1,165 km (724 mi) north of Livingston Island, 606 km (377 mi) northeast of Cape Horn, 358 km (222 mi) northeast of Isla de los Estados, and 510 km (320 mi) east of the Atlantic entrance to Magellan Strait. With an area of 265.8 km2 (102.6 sq mi) Weddell is the third largest island in the archipelago after East Falkland and West Falkland, and one of the largest private islands in the world. It has only one inhabited location, Weddell Settlement, with a single digit population engaged in sheep farming and tourism services. The island offers walks to wildlife watching sites and scenery destinations including some spectacular landscapes featuring the famous Falklands stone runs. Weddell is both an Important Plant Area and a priority Key Biodiversity Area. It is a remote place, infrequently visited by a resupply ship and occasionally by private yachts, accessible by air with a short (some 200 km (120 mi)) if expensive flight from the Falklands capital, Stanley.
  • 1.0K
  • 02 Nov 2022
Topic Review
Mineral Physics
Mineral physics is the study of mineralogical problems through the application of condensed matter physics and solid-state chemistry.  
  • 1.0K
  • 31 May 2021
Topic Review
Thalassocnus
Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths. They have been found in the Pisco Formation of Peru and the Bahía Inglesa, Coquimbo, and Horcón formations of Chile. Thalassocninae has been placed in both the families Megatheriidae and Nothrotheriidae. Thalassocnus evolved several marine adaptations over the course of 4 million years, such as dense and heavy bones to counteract buoyancy, the internal nostrils migrating farther into the head to help with breathing while completely submerged, the snout becoming wider and more elongated to consume aquatic plants better, and the head angling farther and farther downwards to aid in bottom feeding. The long tail was probably used for diving and balance similarly to the modern day beaver (Castor spp.) and platypus (Ornithorhynchus anatinus). Thalassocnus probably walked across the seafloor and dug up food with its claws. They probably could not do high-powered swimming, relying on paddling if necessary. Early Thalassocnus were probably generalist grazers eating seaweed and seagrasses close to shore, whereas later species specialized on seagrasses farther off the coast. They were probably preyed upon by sharks and macroraptorial sperm whales such as Acrophyseter. Thalassocnus were found in formations with large marine mammal and shark assemblages.
  • 993
  • 27 Sep 2022
Topic Review
List of Paleobiota of the Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has a wide assortment of taxa represented in its fossil record, including dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period. (mostly from Foster ; the higher-level classifications will vary as new finds are made.
  • 964
  • 09 Nov 2022
Topic Review
Armenian Highlands
The Armenian Highlands (Armenian: Հայկական լեռնաշխարհ, romanized: Haykakan leṙnašxarh; also known as the Armenian Upland, Armenian plateau, or Armenian tableland) is the most central and the highest of the three plateaus that together form the northern sector of Western Asia. Clockwise starting from the west, the Armenian Highlands are bounded by the Anatolian plateau, the Caucasus, the Kura-Aras lowlands, the Iranian Plateau, and Mesopotamia. The highlands are divided into western and eastern regions, defined by the Ararat Valley where Mount Ararat is located. Western Armenia is nowadays referred to as eastern Anatolia, and Eastern Armenia as the Lesser Caucasus or Caucasus Minor, and historically as the Anti-Caucasus, meaning "opposite the Caucasus". During the Iron Age, the region was known by variations of the name Ararat (Urartu, Uruatri, Urashtu). Later, the Highlands were known as Armenia Major, a central region to the history of Armenians, and one of the four geopolitical regions associated with Armenians, the other three being Armenia Minor, Sophene, and Commagene. The population of the region has been primarily Armenian for most of its known history. Prior to the appearance of nominally Armenian people in historical records, historians have hypothesized that the region must have been home to various ethnic groups who became homogenous when the Armenian language came to prominence. The population of the Armenian Highlands seem to have had a high level of regional genetic continuity for over 6,000 years. Recent studies have shown that the Armenian people are indigenous to the Armenian Highlands and form a distinct genetic isolate in the region. The region was also inhabited during Antiquity by minorities such as Assyrians, Georgians, Greeks, Jews, and Iranians. During the Middle Ages, Arabs and particularly Turkmens and Kurds settled in large numbers in the Armenian Highlands. The Christian population of the western half of the region was exterminated during the Armenian genocide of 1915. Today, the eastern half is mainly inhabited by Armenians, Azerbaijanis and Georgians, while the western half is mainly inhabited by Kurds (including Yazidis), Turks, Azerbaijanis, Armenians (included crypto-Armenians and Hemshins) and Zazas. The region was administered for most of its known history by Armenian nobility and states, whether it was as part of a fully independent Armenian state, as vassals, or as part of a foreign state. Since the 1040s, the highlands have been under the rule of various Turkic peoples and the Safavid dynasty, with pockets of Armenian autonomy in places such as Artsakh. Much of Eastern Armenia, which had been ruled by the Safavids from the 16th century, became part of the Russian Empire in 1828 and was later incorporated into the Soviet Union, while much of Western Armenia was under the rule of the Ottoman Empire and later incorporated into Turkey. Today, the region is divided between Turkey, Georgia, Armenia, Azerbaijan and Iran.
  • 959
  • 07 Nov 2022
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