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60-587: The Denton Hills comprise a series of eastward-trending ridges and valleys circumscribed by Howchin Glacier , Armitage Saddle , Blue Glacier , the coast, and Walcott Bay . The highest summits, Mount Kowalczyk at 1,703 metres (5,587 ft), and Goat Mountain at 1,634 metres (5,361 ft), rise from Hobbs Ridge in the northern part of the foothills. Elevations decrease southward as in Kahiwi Maihao Ridge , 1,045 metres (3,428 ft) high near

120-410: A glacier or snowfield. Ablation refers to the melting of snow or ice that runs off the glacier, evaporation , sublimation , calving , or erosive removal of snow by wind. Air temperature is typically the dominant control of ablation, with precipitation exercising secondary control. In a temperate climate during ablation season, ablation rates typically average around 2 mm/h. Where solar radiation

180-500: A high cirque just southeast of Mount Rucker and flowing east toward Walcott Glacier. In the measurements made of this glacier by the VUWAE (1960-61), one of the survey angles, by chance, was exactly one radian, and the glacier came to be referred to by this term. 78°14′S 162°51′E  /  78.233°S 162.850°E  / -78.233; 162.850 . A glacier formed by the coalescence of numerous small alpine glaciers on

240-549: A high cirque on the east side of Mount Dromedary in the Royal Society Range. Named by the Victoria University of Wellington Antarctic Expedition (VUWAE) (1960-61) for its proximity to Mount Dromedary. 78°16′00″S 163°32′00″E  /  78.2666667°S 163.5333333°E  / -78.2666667; 163.5333333 . A meltwater stream from Koettlitz Glacier on the east side of The Bulwark,

300-481: A high degree of target specificity. The genetic ablation techniques described could prove useful in battling cancer. Electro-ablation , is a process that removes material from a metallic workpiece to reduce surface roughness . Electro-ablation breaks through highly resistive oxide surfaces, such as those found on titanium and other exotic metals and alloys without melting the underlying non-oxidised metal or alloy. This allows very quick surface finishing The process

360-468: A house. There have been many experiments done to demonstrate the effect of debris on the surface of glaciers. Yoshiyuki Fujii, a professor at the National Institute of Polar Research , designed an experiment that showed ablation rate was accelerated under a thin debris layer and was retarded under a thick one as compared with that of a natural snow surface. This science is significant due to

420-574: A large Antarctic glacier lying west of Mount Morning and Mount Discovery in the Royal Society Range , flowing from the vicinity of Mount Cocks northeastward between Brown Peninsula and the mainland into the ice shelf of McMurdo Sound . Koettlitz Glacier was discovered by the British National Antarctic Expedition (1901–04) which named it for Dr. Reginald Koettlitz , physician and botanist of

480-495: A minimum absorption depth. While these lasers can average a low power, they can offer peak intensity and fluence given by: while the peak power is Surface ablation of the cornea for several types of eye refractive surgery is now common, using an excimer laser system ( LASIK and LASEK ). Since the cornea does not grow back, laser is used to remodel the cornea refractive properties to correct refraction errors , such as astigmatism , myopia , and hyperopia . Laser ablation

540-467: A mountain outlier south of Walcott Bay, Scott Coast. The stream flows north and then west, following the perimeter of The Bulwark to enter Trough Lake and the Alph River system. Named by New Zealand Geographic Board (NZGB) (1994) in association with The Bulwark. 78°12′S 163°45′E  /  78.2°S 163.75°E  / -78.2; 163.75 . A small river, flowing in summertime, on

600-833: A névé in the area between Mount Kempe and Mount Huggins. It joins the Pipecleaner Glacier 2 nautical miles (3.7 km; 2.3 mi) south of the confluence of the latter with the Radian Glacier. So named by the VUWAE, 1960-61, because it was up this glacier that the geologists traversed to the Koettlitz-Skelton divide at the ridge crest in order to gain their only glimpse of the polar plateau in January 1961. 78°31′S 162°30′E  /  78.517°S 162.500°E  / -78.517; 162.500 . Mountain, 2,440 metres (8,010 ft) high, in

660-486: A population or culture are destroyed or removed. Both can be used as experimental tools, as in loss-of-function experiments. In medicine, ablation is the removal of a part of biological tissue , usually by surgery . Surface ablation of the skin ( dermabrasion , also called resurfacing because it induces regeneration ) can be carried out by chemicals (chemoablation), by lasers ( laser ablation ), by freezing ( cryoablation ), or by electricity ( fulguration ). Its purpose

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720-481: A protoplanetary disk would result in significant ablation of the disk, and this ablation would strip a significant amount of protoplanetary material from the disk – but not necessarily destroy the disk entirely. This is an important point because a disk that survives such an interaction with sufficient material leftover to form a planetary system may inherit an altered disk chemistry from the SNR, which could have effects on

780-565: Is also named after him. Download coordinates as: Major features include, from north to south: [REDACTED]  This article incorporates public domain material from websites or documents of the United States Geological Survey . Howchin Glacier Koettlitz Glacier ( 78°15′S 164°15′E  /  78.250°S 164.250°E  / -78.250; 164.250 ) is

840-451: Is also used to remove part of the uterine wall in women with menstruation and adenomyosis problems in a process called endometrial ablation . Researchers have demonstrated a successful technique for ablating subsurface tumors with minimal thermal damage to surrounding healthy tissue, by using a focused laser beam from an ultra-short pulse diode laser source. Antifouling paints and other related coatings are routinely used to prevent

900-591: Is blocked by the Koettlitz Glacier. Under this hypothesis, the glacier may have been thicker at the coast due to buttressing, but may have been no thicker, perhaps even thinner upstream due to reduced accumulation. This is in contrast to the view that glaciers feeding the Ross Sea would have been larger during the LGM due to increased accumulation, and the ice shelf smaller. The Koettlitz Ice Tongue lies along

960-443: Is calculated to be sufficient to survive the heat it will encounter on its mission. There is an entire branch of spaceflight research involving the search for new fireproofing materials to achieve the best ablative performance; this function is critical to protect the spacecraft occupants and payload from otherwise excessive heat loading. The same technology is used in some passive fire protection applications, in some cases by

1020-419: Is capable of providing surface finishing for a wide range of exotic and widely used metals and alloys, including: titanium, stainless steel, niobium, chromium–cobalt, Inconel , aluminium, and a range of widely available steels and alloys. Electro-ablation is very effective at achieving high levels of surface finishing in holes, valleys and hidden or internal surfaces on metallic workpieces (parts). The process

1080-402: Is carried away from the spacecraft by the gases generated by the ablative process, and never penetrates the surface material, so the metallic and other sensitive structures they protect, remain at a safe temperature. As the surface burns and disperses into space, the remaining solid material continues to insulate the craft from ongoing heat and superheated gases. The thickness of the ablative layer

1140-406: Is often used in the context of laser ablation , a process in which a laser dissolves a material's molecular bonds . For a laser to ablate tissues, the power density or fluence must be high, otherwise thermocoagulation occurs, which is simply thermal vaporization of the tissues. Rotablation is a type of arterial cleansing that consists of inserting a tiny, diamond-tipped, drill-like device into

1200-500: Is particularly applicable to components produced by additive manufacturing process, such as 3D-printed metals. These components tend to be produced with roughness levels well above 5–20 micron. Electro-ablation can be used to quickly reduce the surface roughness to less than 0.8 micron, allowing the post-process to be used for volume production surface finishing. In glaciology and meteorology , ablation—the opposite of accumulation—refers to all processes that remove snow, ice, or water from

1260-413: Is potentially a much more efficient method of removing unwanted cells, such as tumor cells, because large numbers of animals lacking specific cells could be generated. Genetically ablated lines can be maintained for a prolonged period of time and shared within the research community. Researchers at Columbia University report of reconstituted caspases combined from C. elegans and humans, which maintain

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1320-405: Is the dominant cause of snow ablation (e.g., if air temperatures are low under clear skies), characteristic ablation textures such as suncups and penitentes may develop on the snow surface. Ablation can refer to mass loss from the upper surface of a glacier or ocean-driven melt and calving on the face of a glacier terminus. Ablation can refer either to the processes removing ice and snow or to

1380-410: Is the removal of a component of an AI system. The term is by analogy with biology: removal of components of an organism. Biological ablation is the removal of a biological structure or functionality. Genetic ablation is another term for gene silencing , in which gene expression is abolished through the alteration or deletion of genetic sequence information. In cell ablation, individual cells in

1440-438: Is to put enough of this material in the way of the fire that a level of fire-resistance rating can be maintained, as demonstrated in a fire test . Ablative materials usually have a large concentration of organic matter that is reduced by fire to ashes. In the case of silicone, organic rubber surrounds very finely divided silica dust (up to 380 m of combined surface area of all the dust particles per gram of this dust ). When

1500-541: Is to remove skin spots, aged skin , wrinkles , thus rejuvenating it. Surface ablation is also employed in otolaryngology for several kinds of surgery, such as the one for snoring . Radiofrequency ablation (RFA) is a method of removing aberrant tissue from within the body via minimally invasive procedures, it is used to cure a variety of cardiac arrhythmia such as supraventricular tachycardia , Wolff–Parkinson–White syndrome (WPW), ventricular tachycardia , and more recently as management of atrial fibrillation . The term

1560-579: The heat of atmospheric reentry and the Kestrel second stage rocket engine designed for exclusive use in an environment of space vacuum since no heat convection is possible. In a basic sense, ablative material is designed so that instead of heat being transmitted into the structure of the spacecraft, only the outer surface of the material bears the majority of the heating effect. The outer surface chars and burns away – but quite slowly, only gradually exposing new fresh protective material beneath. The heat

1620-459: The NW slopes of Mount Morning on the south margin of upper Koettlitz Glacier. Named by US-ACAN in 1994 after Roger A. Barlow, USGS cartographer, a member of the satellite surveying team at South Pole Station, winter party 1992. 78°25′S 162°43′E  /  78.417°S 162.717°E  / -78.417; 162.717 . A rocky spur 3 nautical miles (5.6 km; 3.5 mi) long, lying at

1680-586: The Royal Society Range toward Walcott Bay. Named by Taylor of the BrAE (1910-13), presumably for Charles Doolittle Walcott , Director of the U.S. Geological Survey (1894-1907) and Secretary of the Smithsonian Institution, 1907-28. 78°12′S 163°22′E  /  78.200°S 163.367°E  / -78.200; 163.367 . Glacier between the Ward and Walcott Glaciers, on the east side of

1740-782: The Royal Society Range. Discovered by a party led by Griffith Taylor of the BrAE (1910-13) and named for Prof. W. Howchin, geologist of Adelaide. 78°13′00″S 163°25′00″E  /  78.2166667°S 163.4166667°E  / -78.2166667; 163.4166667 . A meltwater stream draining from the south side of Howchin Glacier. It flows eastward into Howchin Lake southward of Howchin North Stream. Named by New Zealand Geographic Board (NZGB) (1994) in association with Howchin Glacier. 78°12′00″S 163°25′00″E  /  78.2°S 163.4166667°E  / -78.2; 163.4166667 }. Description: A meltwater stream draining from

1800-451: The ablation rate can produce long-lived protection from the deleterious effects of biofouling. Firestopping and fireproofing products can be ablative in nature. This can mean endothermic materials, or merely materials that are sacrificial and become "spent" over time while exposed to fire , such as silicone firestop products. Given sufficient time under fire or heat conditions, these products char away, crumble, and disappear. The idea

1860-399: The affected artery to remove fatty deposits or plaque. The procedure is used in the treatment of coronary heart disease to restore blood flow. Microwave ablation (MWA) is similar to RFA but at higher frequencies of electromagnetic radiation. High-intensity focused ultrasound (HIFU) ablation removes tissue from within the body noninvasively. Bone marrow ablation is a process whereby

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1920-421: The buildup of microorganisms and other animals, such as barnacles for the bottom hull surfaces of recreational, commercial and military sea vessels. Ablative paints are often utilized for this purpose to prevent the dilution or deactivation of the antifouling agent. Over time, the paint will slowly decompose in the water, exposing fresh antifouling compounds on the surface. Engineering the antifouling agents and

1980-467: The case in certain clusters , e.g. in the Trapezium cluster . Since massive stars tend to collapse through supernovae at the end of their lives, research is now investigating what role the shockwave of such an explosion, and the resulting supernova remnant (SNR), would play if it occurred in the line of fire of a protoplanetary disk. According to computationally modelled simulations, a SNR striking

2040-416: The catchment area of the Koettlitz Glacier are listed below. Some may not contribute to the Koettlitz Glacier. 78°27′S 163°00′E  /  78.45°S 163°E  / -78.45; 163 A roughly circular névé about 7 nautical miles (13 km; 8.1 mi) wide at the head of Koettlitz Glacier. The névé is bounded to the west and south by Mount Talmadge , Mount Rees and Mount Cocks; to

2100-627: The center of the group and the Xanadu Hills , 820 metres (2,690 ft) high at the southern end. The principal glaciers ( Hobbs , Blackwelder , Salmon , Garwood , Joyce , Rivard , Miers , Adams , Ward ) flow east but have receded, leaving several dry valleys. The Denton Hills were discovered and roughly mapped by the British National Antarctic Expedition, 1901–04 , under Robert Falcon Scott . The hills were mapped in detail by United States Antarctic Research Program (USARP) and New Zealand Antarctic Research Programme (NZARP) personnel in

2160-568: The colder mid-plane of the disk from dust grains and ices sticking together. These small accretions grow from pebbles to rocks to early baby planets, called planetesimals , then protoplanets , and eventually, full planets . As it is believed that massive stars may play a role in actively triggering star formation (by introducing gravitational instabilities amongst other factors), it is plausible that young, smaller stars with disks may be living relatively nearby to older, more massive stars. This has already been confirmed through observations to be

2220-1185: The east by Mount Morning . Named by United States Advisory Committee on Antarctic Names (US-ACAN) (1994) in association with Koettlitz Glacier. 78°24′S 162°50′E  /  78.400°S 162.833°E  / -78.400; 162.833 . A glacier in the Royal Society Range, 4 nautical miles (7.4 km; 4.6 mi) south of Mount Kempe, flowing southeast into the Koettlitz Glacier. Named by US-ACAN in 1963 for Major James Foster, United States Marine Corps (USMC), assistant air operations officer for U.S. Navy Task Force 43 in Antarctica, 1960. 78°22′S 163°08′E  /  78.367°S 163.133°E  / -78.367; 163.133 . A steep glacier flowing southeast from Mount Dromedary into Koettlitz Glacier. Mapped by United States Geological Survey (USGS) from ground surveys and U.S. Navy air photos, 1956-62. Named by US-ACAN for Lt. Garland Renegar, USN, R4D aircraft pilot at McMurdo Station, 1960. Not: Renagar Glacier. 78°18′S 163°10′E  /  78.300°S 163.167°E  / -78.300; 163.167 . A small alpine glacier occupying

2280-474: The east side of Mount Huggins . Together with Glimpse Glacier it joins the Radian Glacier where that stream meets the north arm of Dismal Ridge . Its surface is marked by innumerable bands of moraine reminiscent of pipecleaners. Named by New Zealand VUWAE, 1960-61. 78°16′S 162°46′E  /  78.267°S 162.767°E  / -78.267; 162.767 . An alpine glacier composed of two segments, separated by an icefall, which flow northeast from

2340-464: The east side of Koettlitz Glacier. Mapped by USGS from ground surveys and Navy air photos. Named by US-ACAN in 1963 for Cdr. James Hahn, USN, public information officer on the staff of the Commander, U.S. Naval Support Force, Antarctica, for several years preceding 1963. 77°56′S 164°35′E  /  77.933°S 164.583°E  / -77.933; 164.583 . Small, dark cape forming

2400-644: The east side of the Koettlitz Glacier. Mapped by USGS from ground surveys and Navy air photos. Named in 1963 by US-ACAN in association with Mount Morning. 78°14′S 163°37′E  /  78.233°S 163.617°E  / -78.233; 163.617 . A bay indenting the coast of Victoria Land between Walcott Glacier and Heald Island. Named by the BrAE (1910-13) in association with Walcott Glacier. 78°15′S 163°49′E  /  78.250°S 163.817°E  / -78.250; 163.817 . An island, 3 nautical miles (5.6 km; 3.5 mi) long and 555 metres (1,821 ft) high, which projects through

2460-602: The expedition. The Koettlitz Glacier appears to have been smaller during the Last Glacial Maximum (LGM) than it is today, while the Ross Ice Shelf was larger. There is evidence that during the LGM the mouth of the Pyramid Trough was blocked by grounded Ross Sea ice until at least 11,000 years ago. In the last 3,000 years the glacier has advanced, and today the mouth of ice-free Pyramid Trough

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2520-430: The glacier body. It is noted that if the slope of a glacier is too high then the debris will continue to move along the glacier to a further location. The sizes and locations of glaciers vary around the world, so depending on the climate and physical geography the varieties of debris can differ. The size and magnitude of the debris is dependent on the area of glacier and can vary from dust-size fragments to blocks as large as

2580-405: The heat digested by the debris-covered area and is calculated. The calculations are dependent on the area and net absorbed heat amounts in regards to the entire debris-covered zones. These types of calculations are done to various glaciers to understand and analyze future patterns of melting. Moraine (glacial debris) is moved by natural processes that allow for down-slope movement of materials on

2640-558: The human bone marrow cells are eliminated in preparation for a bone marrow transplant . This is performed using high-intensity chemotherapy and total body irradiation . As such, it has nothing to do with the vaporization techniques described in the rest of this article. Ablation of brain tissue is used for treating certain neurological disorders , particularly Parkinson's disease , and sometimes for psychiatric disorders as well. Recently, some researchers reported successful results with genetic ablation. In particular, genetic ablation

2700-533: The ice of the Koettlitz Glacier just east of Walcott Bay. Discovered and named by the BrNAE (1901-04) for Seaman William L. Heald, a member of the expedition who saved the life of Ferrar when the latter was suffering from scurvy in 1902. 78°15′S 164°58′E  /  78.250°S 164.967°E  / -78.250; 164.967 . Island 1 nautical mile (1.9 km; 1.2 mi) long, lying 7 nautical miles (13 km; 8.1 mi) north of Mount Discovery, on

2760-409: The importance of long-term availability of water resources and assess glacier response to climate change . Natural resource availability is a major drive behind research conducted in regards to the ablation process and overall study of glaciers. Laser ablation is greatly affected by the nature of the material and its ability to absorb energy, therefore the wavelength of the ablation laser should have

2820-526: The north side of Howchin Glacier in Denton Hills, Scott Coast. It flows eastward into Howchin Lake northward of Howchin South Stream. Named by New Zealand Geographic Board (NZGB) (1994) in association with Howchin Glacier. 78°13′S 163°00′E  /  78.217°S 163.000°E  / -78.217; 163.000 . A glacier on the east side of the Royal Society Range, descending from

2880-533: The north. Walcott Bay is fed by Walcott Glacier and Howchin Glacier. Walcott Glacier in turn is fed by Radian Glacier, Pipecleaner Glacier and Glimpse Glacier. Past is grounding line it flows past Hahn Island at the foot of Mount Discovery. It enters the McMurdo Ice Shelf past Brown Peninsula and Bratina Island to the east. Cape Chocolate is to the west of its mouth, and McMurdo Station and Ross Island are opposite its mouth. Glaciers and streams in

2940-552: The northern side of Koettlitz Glacier, Scott Coast. It rises from Koettlitz ice at the upper end of Pyramid Trough and from south to north includes Pyramid Ponds, Trough Lake, Walcott Lake, Howchin Lake, and Alph Lake. The portion north of Pyramid Trough was explored and named in February 1911 by the British Antarctic Expedition (BrAE) Western Journey Party led by Thomas Griffith Taylor . He reported that

3000-411: The organic rubber is exposed to fire, it burns to ash and leaves behind the silica dust with which the product started. Protoplanetary disks are rotating circumstellar disks of dense gas and dust surrounding young, newly formed stars. Shortly after star formation , stars often have leftover surrounding material that is still gravitationally bound to them, forming primitive disks that orbit around

3060-498: The planetary systems that later form. In spacecraft design, ablation is used to both cool and protect mechanical parts and/or payloads that would otherwise be damaged by extremely high temperatures. Two principal applications are heat shields for spacecraft entering a planetary atmosphere from space and cooling of rocket engine nozzles . Examples include the Apollo Command Module that protected astronauts from

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3120-447: The quantity of ice and snow removed. Debris-covered glaciers have also been shown to greatly impact the ablation process. There is a thin debris layer that can be located on the top of glaciers that intensifies the ablation process below the ice. The debris-covered parts of a glacier that is experiencing ablation are sectioned into three categories which include ice cliffs, ponds, and debris. These three sections allow scientists to measure

3180-570: The south part of the Royal Society Range. It stands at the head of Koettlitz Glacier and forms a part of the divide between the Koettlitz and the lower Skelton Glacier . Discovered by the BrNAE (1901-04) which named it for E.L. Somers Cocks, then Treasurer of the Royal Geographical Society. 78°29′S 163°24′E  /  78.483°S 163.400°E  / -78.483; 163.400 . A group of rocks standing below

3240-457: The south side of Foster Glacier in the Royal Society Range. Named by US-ACAN in 1963 for Lt. Benjamin F. Hooper, helicopter pilot with U.S. Navy Squadron VX-6, who wintered at McMurdo Station in 1960. 78°21′S 163°53′E  /  78.350°S 163.883°E  / -78.350; 163.883 . An ice lake, nearly 2 nautical miles (3.7 km; 2.3 mi) long, lying 9 nautical miles (17 km; 10 mi) north of Mount Morning along

3300-755: The south side of Salmon Bay on the coast of Victoria Land. It is made up of morainic material from the west margin of the Koettlitz Glacier. Discovered by the BrNAE (1901-04) under Scott, and probably so named because of the color of the morainic material. Ablation Ablation ( Latin : ablatio – removal) is the removal or destruction of something from an object by vaporization , chipping, erosive processes, or by other means. Examples of ablative materials are described below, including spacecraft material for ascent and atmospheric reentry , ice and snow in glaciology , biological tissues in medicine and passive fire protection materials. In artificial intelligence (AI), especially machine learning , ablation

3360-532: The star's equator – not too dissimilarly from the rings of Saturn . This occurs because the decrease in the protostellar material's radius during formation increases angular momentum , which means that this remaining material gets whipped into a flattened circumstellar disk around the star. This circumstellar disk may eventually mature into what is referred to as a protoplanetary disk: a disk of gas, dust, ice and other materials from which planetary systems may form. In these disks, orbiting matter starts to accrete in

3420-627: The stream continues north a considerable distance under moraine and ultimately subglacially beneath Koettlitz Glacier to the Ross Sea. This led to the name from a passage in Samuel Taylor Coleridge ’s poem Kubla Khan : “Where Alph the sacred river ran, Through caverns measureless to man, Down to a sunless sea.” 78°14′S 163°15′E  /  78.233°S 163.250°E  / -78.233; 163.250 . Glacier between Radian and Howchin Glaciers, descending eastward from

3480-497: The tongue. As of 2017 only two of these islands are still connected to the ice tongue. The glacier forms to the northeast of Mount Cocks and runs northeast to the north of the Mount Discovery massif. To the north of Hooper Crags it is joined from the west by Foster Glacier and then by Reneger Glacier, below Dromedary Glacier. It continues northeast past Lake Lake Morning to the south and past Walcott Bay and Heald Island to

3540-578: The west shore of McMurdo Sound. It is of major scientific interest due to the unique collection of fish and marine invertebrates on its ablating surface. Between 1910 and 1994 it has retreated significantly. In 1910-13 the ice front was 5 kilometres (3.1 mi) in front of the Dailey Islands . Since then at least 300 square kilometres (120 sq mi) of ice has calved off the ice tongue. A break-out of ice in 1979 or 1980 caused about 80 square kilometres (31 sq mi) of ice to be lost from

3600-857: The years following the International Geophysical Year , 1957–58. The hills were named by the United States Advisory Committee on Antarctic Names (US-ACAN; 1999) after Professor George H. Denton of the Department of Geological Sciences and the Institute for Quaternary Studies, University of Maine , who conducted geological research in the Transantarctic Mountains and Victoria Land (including work in these hills), 1958–99, making more than 25 visits to Antarctica. Denton Glacier

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