Radioglaciology

Last updated

Radioglaciology is the study of glaciers, ice sheets, ice caps and icy moons using ice penetrating radar. It employs a geophysical method similar to ground-penetrating radar and typically operates at frequencies in the MF, HF, VHF and UHF portions of the radio spectrum. [1] [2] [3] [4] This technique is also commonly referred to as "Ice Penetrating Radar (IPR)" or "Radio Echo Sounding (RES)".

Contents

Glaciers are particularly well suited to investigation by radar because the conductivity, imaginary part of the permittivity, and the dielectric absorption of ice are small at radio frequencies resulting in low loss tangent, skin depth, and attenuation values. This allows echoes from the base of the ice sheet to be detected through ice thicknesses greater than 4 km. [5] [6] The subsurface observation of ice masses using radio waves has been an integral and evolving geophysical technique in glaciology for over half a century. [7] [8] [9] [10] [11] [12] [13] [14] Its most widespread uses have been the measurement of ice thickness, subglacial topography, and ice sheet stratigraphy. [15] [8] [5] It has also been used to observe the subglacial and conditions of ice sheets and glaciers, including hydrology, thermal state, accumulation, flow history, ice fabric, and bed geology. [1] In planetary science, ice penetrating radar has also been used to explore the subsurface of the Polar Ice Caps on Mars and comets. [16] [17] [18] Missions are planned to explore the icy moons of Jupiter. [19] [20]

Measurements and applications

Radioglaciology uses nadir facing radars to probe the subsurface of glaciers, ice sheets, ice caps, and icy moons and to detect reflected and scattered energy from within and beneath the ice. [8] This geometry tends to emphasize coherent and specular reflected energy resulting in distinct forms of the radar equation. [21] [22] Collected radar data typically undergoes signal processing ranging from stacking (or pre-summing) to migration to Synthetic Aperture Radar (SAR) focusing in 1, 2, or 3 dimensions. [23] [24] [25] [22] This data is collected using ice penetrating radar systems which range from commercial (or bespoke) ground penetrating radar (GPR) systems [26] [27] to coherent, chirped airborne sounders [28] [29] [30] to swath-imaging, [31] multi-frequency, [32] or polarimetric [33] implementations of such systems. Additionally, stationary, phase-sensitive, and Frequency Modulated Continuous Wave (FMCW) radars [34] [35] [36] have been used to observe snow, [37] ice shelf melt rates, [38] englacial hydrology, [39] ice sheet structure, [40] and vertical ice flow. [41] [42] Interferometric analysis of airborne systems have also been demonstrated to measure vertical ice flow. [43] Additionally, radioglaciological instruments have been developed to operate on autonomous platforms, [44] on in-situ probes, [45] in low-cost deployments, [46] using Software Defined Radios, [47] and exploiting ambient radio signals for passive sounding. [48] [49]

The most common scientific application for radioglaciological observations is measuring ice thickness and bed topography. This includes interpolated "bed maps", [6] [50] [51] [52] widely used in ice sheet modeling and sea level rise projections, studies exploring specific ice-sheet regions, [53] [54] [55] [56] [57] and observations of glacier beds. [58] [59] [60] [61] The strength and character of radar echoes from the bed of the ice sheet are also used to investigate the reflectivity [62] [27] of the bed, the attenuation [63] [64] [65] of radar in the ice, and the morphology of the bed. [66] [67] [68] In addition bed echoes, radar returns from englacial layers [69] are used in studies of the radio stratigraphy of ice sheets [70] [71] [72] [73] [74] including investigations of ice accumulation, [75] [76] [77] [78] [79] flow, [80] [81] [82] [83] and fabric [84] [85] as well as absence or disturbances of that stratigraphy. [86] [87] [88] Radioglaciology data has also been used extensively to study subglacial lakes [89] [90] [91] [92] [93] [94] and glacial hydrology [95] including englacial water, [96] [97] [98] firn aquifers, [99] and their temporal evolution. [100] [39] [101] Ice penetrating radar data has also been used to investigate the subsurface of ice shelves including their grounding zones, [102] [103] melt rates, [104] [105] brine distribution, [106] and basal channels. [107]

Planetary exploration

There are currently two ice-penetrating radars orbiting Mars: MARSIS and SHARAD. [108] [109] [110] [111] [112] [113] [114] [115] [116] [117] An ice penetrating radar was also part of the ROSETTA mission to comet 67P/Churyumov–Gerasimenko. [17] Ice penetrating radars are also included in the payloads of two planned missions to the icy moons of Jupiter: JUICE and Europa Clipper. [19] [118] [119] [120] [121] [122] [123]

IGS symposia

The International Glaciological Society (IGS) holds a periodic series of symposia focused on radioglaciology. In 2008, the "Symposium on Radioglaciology and its Applications" was hosted at the Technical University of Madrid.  In 2013, the "Symposium on Radioglaciology" was hosted at the University of Kansas. In 2019, the "Symposium of Five Decades of Radioglaciology" was hosted at Stanford University.

Further reading

The following books and papers cover important topics in radioglaciology

Research institutions

Research and education in radioglaciology is undertaken at universities and research institutes around the world.  These groups found in institutions and departments that span physical geography, geophysics, earth science, planetary science, electrical engineering, and related disciplines.

Related Research Articles

<span class="mw-page-title-main">Ice sheet</span> Large mass of glacial ice

In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi). The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.

<span class="mw-page-title-main">West Antarctic Ice Sheet</span> Segment of Antarctic ice sheet

The West Antarctic Ice Sheet (WAIS) is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. It is classified as a marine-based ice sheet, meaning that its bed lies well below sea level and its edges flow into floating ice shelves. The WAIS is bounded by the Ross Ice Shelf, the Ronne Ice Shelf, and outlet glaciers that drain into the Amundsen Sea.

<span class="mw-page-title-main">Berkner Island</span> Ice rise in the British Antarctic Territory, Antarctica

Berkner Island is an Antarctic ice rise, where bedrock below sea level has caused the surrounding ice sheet to create a dome. If the ice cap were removed, the island would be underwater. Berkner Island is completely ice-covered and is about 320 kilometres (200 mi) long and 150 kilometres (93 mi) wide, with an area of 44,000 km2 (17,000 sq mi). It is surrounded by the Filchner-Ronne Ice Shelf. The northernmost point of the Berkner is about 20 kilometres (12 mi) from the open sea. It lies in the overlapping portion of the Argentine and the British Antarctic territorial claims.

<span class="mw-page-title-main">Marie Byrd Land</span> Unclaimed West Antarctic region

Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of 1,610,000 km2 (620,000 sq mi), it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century.

<span class="mw-page-title-main">Ground-penetrating radar</span> Geophysical method that uses radar pulses to image the subsurface

Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. It is a non-intrusive method of surveying the sub-surface to investigate underground utilities such as concrete, asphalt, metals, pipes, cables or masonry. This nondestructive method uses electromagnetic radiation in the microwave band of the radio spectrum, and detects the reflected signals from subsurface structures. GPR can have applications in a variety of media, including rock, soil, ice, fresh water, pavements and structures. In the right conditions, practitioners can use GPR to detect subsurface objects, changes in material properties, and voids and cracks.

<span class="mw-page-title-main">Subglacial lake</span> Lake under a glacier

A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where liquid water can exist above the lower melting point of ice under high pressure. Over time, the overlying ice gradually melts at a rate of a few millimeters per year. Meltwater flows from regions of high to low hydraulic pressure under the ice and pools, creating a body of liquid water that can be isolated from the external environment for millions of years.

<span class="mw-page-title-main">Denman Glacier</span> Glacier in Queen Mary Land, Antarctica

Denman Glacier is a glacier that is 11 to 16 km wide, descending north some 110 km (70 mi), which debouches into the Shackleton Ice Shelf east of David Island, Queen Mary Land. It was discovered in November 1912 by the Western Base party of the Australasian Antarctic Expedition under Sir Douglas Mawson. Mawson named the glacier for Lord Denman, Governor-General of Australia in 1911, a patron of the expedition.

<span class="mw-page-title-main">Pine Island Glacier</span> Large ice stream, fastest melting glacier in Antarctica

Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.

<span class="mw-page-title-main">Thwaites Glacier</span> Antarctic glacier

Thwaites Glacier is an unusually broad and vast Antarctic glacier located east of Mount Murphy, on the Walgreen Coast of Marie Byrd Land. It was initially sighted by polar researchers in 1940, mapped in 1959–1966 and officially named in 1967, after the late American glaciologist Fredrik T. Thwaites. The glacier flows into Pine Island Bay, part of the Amundsen Sea, at surface speeds which exceed 2 kilometres (1.2 mi) per year near its grounding line. Its fastest-flowing grounded ice is centered between 50 and 100 kilometres east of Mount Murphy. Like many other parts of the cryosphere, it has been adversely affected by climate change, and provides one of the more notable examples of the retreat of glaciers since 1850.

Photoclinometry, or shape-from-shading, is the process by which a 2-dimensional image of a surface is transformed into a surface map that represents different levels of elevation. It uses the shadows and light direction as reference points. It is used mostly to depict the surface of sculptures, to give an idea of how it would look in 3-dimensions. The techniques depend on very specific conditions, especially light direction.

<span class="mw-page-title-main">Totten Glacier</span> Glacier in Antarctica

Totten Glacier is a large glacier draining a major portion of the East Antarctic Ice Sheet, through the Budd Coast of Wilkes Land in the Australian Antarctic Territory. The catchment drained by the glacier is estimated at 538,000 km2 (208,000 sq mi), extending approximately 1,100 km (680 mi) into the interior and holds the potential to raise sea level by at least 3.5 m (11 ft). Totten drains northeastward from the continental ice but turns northwestward at the coast where it terminates in a prominent tongue close east of Cape Waldron. It was first delineated from aerial photographs taken by USN Operation Highjump (1946–47), and named by Advisory Committee on Antarctic Names (US-ACAN) for George M. Totten, midshipman on USS Vincennes of the United States Exploring Expedition (1838–42), who assisted Lieutenant Charles Wilkes with correction of the survey data obtained by the expedition.

<span class="mw-page-title-main">West Antarctic Rift System</span> Series of rift valleys between East and West Antarctica

The West Antarctic Rift System is a series of rift valleys between East and West Antarctica. It encompasses the Ross Embayment, the Ross Sea, the area under the Ross Ice Shelf and a part of Marie Byrd Land in West Antarctica, reaching to the base of the Antarctic Peninsula. It has an estimated length of 3,000 km (1,900 mi) and a width of approximately 700 km (430 mi). Its evolution is due to lithospheric thinning of an area of Antarctica that resulted in the demarcation of East and West Antarctica. The scale and evolution of the rift system has been compared to that of the Basin and Range Province of the Western United States.

Aurora Subglacial Basin is a large subglacial basin of Wilkes Land to the west of Dome Charlie and trending northwest toward the coast in the vicinity of Shackleton Ice Shelf. The basin was delineated by the SPRI-NSF-TUD airborne radio echo sounding program, 1967–79, and named after Aurora, the ship of the Australasian Antarctic Expedition, 1911–14, led by Douglas Mawson.

<span class="mw-page-title-main">Crane Glacier</span> Glacier in the Aristotle Mountains of the Antarctic Peninsula

Crane Glacier is a narrow glacier which flows 30 miles (50 km) in an east-northeasterly direction along the northwest side of Aristotle Mountains to enter Spillane Fjord south of Devetaki Peak, on the east coast of the Antarctic Peninsula. Sir Hubert Wilkins photographed this feature from the air in 1928 and gave it the name "Crane Channel", after C.K. Crane of Los Angeles, reporting that it appeared to be a channel cutting in an east-west direction across the peninsula. The name was altered to "Crane Inlet" following explorations along the west coast of the peninsula in 1936 by the British Graham Land Expedition, which proved that no through channel from the east coast existed as indicated by Wilkins. Comparison of Wilkins' photograph of this feature with those taken in 1947 by the Falkland Islands Dependencies Survey shows that Wilkins' "Crane Channel" is this glacier, although it lies about 75 miles (120 km) northeast of the position originally reported by Wilkins.

Fletcher Ice Rise, or Fletcher Promontory, is a large ice rise, 100 miles (160 km) long and 40 miles (64 km) wide, at the southwest side of the Ronne Ice Shelf, Antarctica. The feature is completely ice covered and rises between Rutford Ice Stream and Carlson Inlet. The ice rise was observed, photographed and roughly sketched by Lieutenant Ronald F. Carlson, U.S. Navy, in the course of a C-130 aircraft flight of December 14–15, 1961 from McMurdo Sound to this vicinity and returning. It was mapped in detail by the U.S. Geological Survey from Landsat imagery taken 1973–74, and was named by the Advisory Committee on Antarctic Names for Joseph O. Fletcher, director of the Office of Polar Programs, National Science Foundation, 1971–74.

Raymond Effect is a flow effect in ice sheets, occurring at flow divides, which gives rise to disturbances in the stratigraphy, showing unusual arches or anticlines called Raymond Arches. The stratigraphy is detected by radio-echo sounding. The Raymond Effect arises from the unusual flow properties of ice, as its viscosity decreases with stress. It is of importance because it provides field evidence for the flow properties of ice. In addition, it permits dating of changes in ice flow and the establishment of changes in ice thickness. The effect was first predicted by Charles F. Raymond. Raymond Arches and the Raymond Effect have been observed at numerous other ice divides e.g. Siple Dome, Fletcher Ice Rise, Berkner Island, Roosevelt Island, and Korff Ice Rise.

<span class="mw-page-title-main">Frank Pattyn</span> Belgian glaciologist

Frank Jean-Marie Léon Pattyn is a Belgian glaciologist and professor at the Université libre de Bruxelles. He is best known for developing ice-sheet models and leading model intercomparisons.

Martin J. Siegert is a British glaciologist, and Deputy Vice Chancellor (Cornwall) at the University of Exeter. He co-Chairs the Diversity in Polar Science Initiative, and has spoken about socio-economic inclusion in Polar Science and indeed broader society.

<span class="mw-page-title-main">Subglacial lakes on Mars</span>

Salty subglacial lakes are controversially inferred from radar measurements to exist below the South Polar Layered Deposits (SPLD) in Ultimi Scopuli of Mars' southern ice cap. The idea of subglacial lakes due to basal melting at the polar ice caps on Mars was first hypothesized in the 1980s. For liquid water to persist below the SPLD, researchers propose that perchlorate is dissolved in the water, which lowers the freezing temperature, but other explanations such as saline ice or hydrous minerals have been offered. Challenges for explaining sufficiently warm conditions for liquid water to exist below the southern ice cap include low amounts of geothermal heating from the subsurface and overlying pressure from the ice. As a result, it is disputed whether radar detections of bright reflectors were instead caused by other materials such as saline ice or deposits of minerals such as clays. While lakes with salt concentrations 20 times that of the ocean pose challenges for life, potential subglacial lakes on Mars are of high interest for astrobiology because microbial ecosystems have been found in deep subglacial lakes on Earth, such as in Lake Whillans in Antarctica below 800 m of ice.

An ice shelf basal channel is a type of subglacial meltwater channel that forms on the underside of floating ice shelves connected to ice sheets. Basal channels are generally rounded cavities which form parallel to ice sheet flow. These channels are found mainly around the Greenland and Antarctic ice sheets in places with relatively warm ocean water. West Antarctica in particular has the highest density of basal channels in the world. Basal channels can be tens of kilometers long, kilometers wide, and incise hundreds of meters up into an ice shelf. These channels can evolve and grow just as rapidly as ice shelves can, with some channels having incision rates approaching 22 meters per year. Basal channels are categorized based on what mechanisms created them and where they formed.

References

  1. 1 2 Schroeder, Dustin M.; Bingham, Robert G.; Blankenship, Donald D.; Christianson, Knut; Eisen, Olaf; Flowers, Gwenn E.; Karlsson, Nanna B.; Koutnik, Michelle R.; Paden, John D.; Siegert, Martin J. (April 2020). "Five decades of radioglaciology". Annals of Glaciology. 61 (81): 1–13. Bibcode:2020AnGla..61....1S. doi: 10.1017/aog.2020.11 . ISSN   0260-3055.
  2. ↑ Kulessa, B.; Booth, A. D.; Hobbs, A.; Hubbard, A. L. (2008-12-18). "Automated monitoring of subglacial hydrological processes with ground-penetrating radar (GPR) at high temporal resolution: scope and potential pitfalls". Geophysical Research Letters. 35 (24): L24502. Bibcode:2008GeoRL..3524502K. doi: 10.1029/2008GL035855 . hdl: 2160/7032 . ISSN   0094-8276.
  3. ↑ Bogorodsky, VV; Bentley, CR; Gudmandsen, PE (1985). Radioglaciology. D. Reidel Publishing.
  4. ↑ Pellikka, Petri; Rees, W. Gareth, eds. (2009-12-16). Remote Sensing of Glaciers: Techniques for Topographic, Spatial and Thematic Mapping of Glaciers (0 ed.). CRC Press. doi:10.1201/b10155. ISBN   978-0-429-20642-9. S2CID   129205832.
  5. 1 2 Bamber, J. L.; Griggs, J. A.; Hurkmans, R. T. W. L.; Dowdeswell, J. A.; Gogineni, S. P.; Howat, I.; Mouginot, J.; Paden, J.; Palmer, S.; Rignot, E.; Steinhage, D. (2013-03-22). "A new bed elevation dataset for Greenland". The Cryosphere. 7 (2): 499–510. Bibcode:2013TCry....7..499B. doi: 10.5194/tc-7-499-2013 . hdl: 1808/18762 . ISSN   1994-0424.
  6. 1 2 Fretwell, P.; Pritchard, H. D.; Vaughan, D. G.; Bamber, J. L.; Barrand, N. E.; et al. (28 February 2013). "Bedmap2: improved ice bed, surface and thickness datasets for Antarctica" (PDF). The Cryosphere. 7 (1): 390. Bibcode:2013TCry....7..375F. doi: 10.5194/tc-7-375-2013 . Retrieved 6 January 2014.
  7. ↑ Allen, Christopher (September 26, 2008). "A Brief History Of Radio – Echo Sounding Of Ice".
  8. 1 2 3 Dowdeswell, J A; Evans, S (2004-10-01). "Investigations of the form and flow of ice sheets and glaciers using radio-echo sounding". Reports on Progress in Physics. 67 (10): 1821–1861. Bibcode:2004RPPh...67.1821D. doi:10.1088/0034-4885/67/10/R03. ISSN   0034-4885. S2CID   250845954.
  9. ↑ Drewry, DJ (1983). Antarctica: Glaciological and Geophysical Folio, Vol. 2. University of Cambridge, Scott Polar Research Institute Cambridge.
  10. ↑ Gudmandsen, P. (December 1969). "Airborne Radio Echo Sounding of the Greenland Ice Sheet". The Geographical Journal. 135 (4): 548–551. Bibcode:1969GeogJ.135..548G. doi:10.2307/1795099. JSTOR   1795099.
  11. ↑ Robin, G. de Q. (1975). "Radio-Echo Sounding: Glaciological Interpretations and Applications". Journal of Glaciology. 15 (73): 49–64. doi: 10.3189/S0022143000034262 . ISSN   0022-1430.
  12. ↑ Steenson, BO (1951). Radar Methods for the Exploration of Glaciers (PhD). California Institute of Technology.
  13. ↑ Stern, W (1930). Principles, methods and results of electrodynamic thickness measurement of glacier ice. Zeitschrift für Gletscherkunde 18, 24.
  14. ↑ Turchetti, Simone; Dean, Katrina; Naylor, Simon; Siegert, Martin (September 2008). "Accidents and opportunities: a history of the radio echo-sounding of Antarctica, 1958–79". The British Journal for the History of Science. 41 (3): 417–444. doi:10.1017/S0007087408000903. hdl: 1842/2975 . ISSN   0007-0874. S2CID   55339188.
  15. ↑ Bingham, R. G.; Siegert, M. J. (2007-03-01). "Radio-Echo Sounding Over Polar Ice Masses". Journal of Environmental & Engineering Geophysics. 12 (1): 47–62. Bibcode:2007JEEG...12...47B. doi:10.2113/JEEG12.1.47. hdl: 2164/11013 . ISSN   1083-1363.
  16. ↑ Picardi, G. (2005-12-23). "Radar Soundings of the Subsurface of Mars". Science. 310 (5756): 1925–1928. Bibcode:2005Sci...310.1925P. doi: 10.1126/science.1122165 . ISSN   0036-8075. PMID   16319122.
  17. 1 2 Kofman, W.; Herique, A.; Barbin, Y.; Barriot, J.-P.; Ciarletti, V.; Clifford, S.; Edenhofer, P.; Elachi, C.; Eyraud, C.; Goutail, J.-P.; Heggy, E. (2015-07-31). "Properties of the 67P/Churyumov-Gerasimenko interior revealed by CONSERT radar". Science. 349 (6247): aab0639. Bibcode:2015Sci...349b0639K. doi: 10.1126/science.aab0639 . ISSN   0036-8075. PMID   26228153.
  18. ↑ Seu, Roberto; Phillips, Roger J.; Biccari, Daniela; Orosei, Roberto; Masdea, Arturo; Picardi, Giovanni; Safaeinili, Ali; Campbell, Bruce A.; Plaut, Jeffrey J.; Marinangeli, Lucia; Smrekar, Suzanne E. (2007-05-18). "SHARAD sounding radar on the Mars Reconnaissance Orbiter". Journal of Geophysical Research. 112 (E5): E05S05. Bibcode:2007JGRE..112.5S05S. doi: 10.1029/2006JE002745 . ISSN   0148-0227.
  19. 1 2 Blankenship, DD (2018). "Reasons for Europa". 42nd COSPAR Scientific Assembly. 42. and 5 others.
  20. ↑ Bruzzone, L; Alberti, G; Catallo, C; Ferro, A; Kofman, W; Orosei, R (May 2011). "Subsurface Radar Sounding of the Jovian Moon Ganymede". Proceedings of the IEEE. 99 (5): 837–857. doi:10.1109/JPROC.2011.2108990. ISSN   0018-9219. S2CID   12738030.
  21. ↑ Haynes, Mark S. (April 2020). "Surface and subsurface radar equations for radar sounders". Annals of Glaciology. 61 (81): 135–142. Bibcode:2020AnGla..61..135H. doi: 10.1017/aog.2020.16 . ISSN   0260-3055.
  22. 1 2 Peters, M.E.; Blankenship, D.D.; Carter, S.P.; Kempf, S.D.; Young, D.A.; Holt, J.W. (September 2007). "Along-Track Focusing of Airborne Radar Sounding Data From West Antarctica for Improving Basal Reflection Analysis and Layer Detection". IEEE Transactions on Geoscience and Remote Sensing. 45 (9): 2725–2736. Bibcode:2007ITGRS..45.2725P. doi:10.1109/TGRS.2007.897416. ISSN   0196-2892. S2CID   22808977.
  23. ↑ Ferro, A. (2019-06-18). "Squinted SAR focusing for improving automatic radar sounder data analysis and enhancement". International Journal of Remote Sensing. 40 (12): 4762–4786. Bibcode:2019IJRS...40.4762F. doi:10.1080/01431161.2019.1573339. ISSN   0143-1161. S2CID   133653325.
  24. ↑ Zhang, Qiuwang; Kandic, Ivana; Barfield, Jeffrey T.; Kutryk, Michael J. (2013). "Coculture with Late, but Not Early, Human Endothelial Progenitor Cells Up Regulates IL-1βExpression in THP-1 Monocytic Cells in a Paracrine Manner". Stem Cells International. 2013: 859643. doi: 10.1155/2013/859643 . ISSN   1687-966X. PMC   3872420 . PMID   24385987.
  25. ↑ Paden, John; Akins, Torry; Dunson, David; Allen, Chris; Gogineni, Prasad (2010). "Ice-sheet bed 3-D tomography". Journal of Glaciology. 56 (195): 3–11. Bibcode:2010JGlac..56....3P. doi: 10.3189/002214310791190811 . hdl: 1808/18879 . ISSN   0022-1430.
  26. ↑ Booth, Adam D.; Clark, Roger; Murray, Tavi (June 2010). "Semblance response to a ground-penetrating radar wavelet and resulting errors in velocity analysis". Near Surface Geophysics. 8 (3): 235–246. Bibcode:2010NSGeo...8..235B. doi:10.3997/1873-0604.2010008.
  27. 1 2 Tulaczyk, Slawek M.; Foley, Neil T. (2020-12-08). "The role of electrical conductivity in radar wave reflection from glacier beds". The Cryosphere. 14 (12): 4495–4506. Bibcode:2020TCry...14.4495T. doi: 10.5194/tc-14-4495-2020 . ISSN   1994-0416.
  28. ↑ Gogineni, S.; Tammana, D.; Braaten, D.; Leuschen, C.; Akins, T.; Legarsky, J.; Kanagaratnam, P.; Stiles, J.; Allen, C.; Jezek, K. (2001-12-27). "Coherent radar ice thickness measurements over the Greenland ice sheet". Journal of Geophysical Research: Atmospheres. 106 (D24): 33761–33772. Bibcode:2001JGR...10633761G. doi: 10.1029/2001JD900183 . hdl: 1808/15756 .
  29. ↑ Rodriguez-Morales, Fernando; Byers, Kyle; Crowe, Reid; Player, Kevin; Hale, Richard D.; Arnold, Emily J.; Smith, Logan; Gifford, Christopher M.; Braaten, David; Panton, Christian; Gogineni, Sivaprasad (May 2014). "Advanced Multifrequency Radar Instrumentation for Polar Research". IEEE Transactions on Geoscience and Remote Sensing. 52 (5): 2824–2842. Bibcode:2014ITGRS..52.2824R. doi:10.1109/TGRS.2013.2266415. ISSN   0196-2892. S2CID   7287473.
  30. ↑ Yan, J.; Gogineni, P.; O'Neill, C. (July 2018). "L-Band Radar Sounder for Measuing Ice Basal Conditions and Ice-Shelf Melt Rate". IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium. pp. 4135–4137. doi:10.1109/IGARSS.2018.8518210. ISBN   978-1-5386-7150-4. S2CID   53226141.
  31. ↑ Holschuh, N.; Christianson, K.; Paden, J.; Alley, R.B.; Anandakrishnan, S. (2020-03-01). "Linking postglacial landscapes to glacier dynamics using swath radar at Thwaites Glacier, Antarctica". Geology. 48 (3): 268–272. Bibcode:2020Geo....48..268H. doi:10.1130/G46772.1. ISSN   0091-7613. S2CID   213056337.
  32. ↑ Carrer, Leonardo; Bruzzone, Lorenzo (December 2017). "Solving for ambiguities in radar geophysical exploration of planetary bodies by mimicking bats echolocation". Nature Communications. 8 (1): 2248. Bibcode:2017NatCo...8.2248C. doi:10.1038/s41467-017-02334-1. ISSN   2041-1723. PMC   5740182 . PMID   29269728.
  33. ↑ Dall, Jorgen; Corr, Hugh F. J.; Walker, Nick; Rommen, Bjorn; Lin, Chung-Chi (July 2018). "Sounding the Antarctic ice sheet from space: A feasibility study based on airborne P-band radar data". IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium. Valencia: IEEE. pp. 4142–4145. doi:10.1109/IGARSS.2018.8518826. ISBN   978-1-5386-7150-4. S2CID   53229440.
  34. ↑ Brennan, Paul V.; Lok, Lai Bun; Nicholls, Keith; Corr, Hugh (2014). "Phase-sensitive FMCW radar system for high-precision Antarctic ice shelf profile monitoring". IET Radar, Sonar & Navigation. 8 (7): 776–786. doi: 10.1049/iet-rsn.2013.0053 . ISSN   1751-8792.
  35. ↑ Lok, L. B.; Brennan, P. V.; Ash, M.; Nicholls, K. W. (July 2015). "Autonomous phase-sensitive radio echo sounder for monitoring and imaging antarctic ice shelves". 2015 8th International Workshop on Advanced Ground Penetrating Radar (IWAGPR). pp. 1–4. doi:10.1109/IWAGPR.2015.7292636. ISBN   978-1-4799-6495-6. S2CID   23122115.
  36. ↑ Vaňková, Irena; Nicholls, Keith W.; Xie, Surui; Parizek, Byron R.; Voytenko, Denis; Holland, David M. (April 2020). "Depth-dependent artifacts resulting from ApRES signal clipping". Annals of Glaciology. 61 (81): 108–113. Bibcode:2020AnGla..61..108V. doi: 10.1017/aog.2020.56 . ISSN   0260-3055.
  37. ↑ Marshall, Hans-Peter; Koh, Gary (2008-04-01). "FMCW radars for snow research". Cold Regions Science and Technology. Research in Cryospheric Science and Engineering. 52 (2): 118–131. Bibcode:2008CRST...52..118M. doi:10.1016/j.coldregions.2007.04.008. ISSN   0165-232X.
  38. ↑ Corr, H. F. J.; Jenkins, A.; Nicholls, K. W.; Doake, C. S. M. (April 2002). "Precise measurement of changes in ice-shelf thickness by phase-sensitive radar to determine basal melt rates: ICE MELT RATES REVEALED BY RADAR". Geophysical Research Letters. 29 (8): 73–1–74-4. doi:10.1029/2001GL014618. S2CID   127638299.
  39. 1 2 Kendrick, A. K.; Schroeder, D. M.; Chu, W.; Young, T. J.; Christoffersen, P.; Todd, J.; Doyle, S. H.; Box, J. E.; Hubbard, A.; Hubbard, B.; Brennan, P. V. (2018-10-16). "Surface Meltwater Impounded by Seasonal Englacial Storage in West Greenland". Geophysical Research Letters. 45 (19): 10, 474. Bibcode:2018GeoRL..4510474K. doi: 10.1029/2018GL079787 . hdl: 10037/13937 . ISSN   0094-8276.
  40. ↑ Young, Tun Jan; Schroeder, Dustin M.; Christoffersen, Poul; Lok, Lai Bun; Nicholls, Keith W.; Brennan, Paul V.; Doyle, Samuel H.; Hubbard, Bryn; Hubbard, Alun (August 2018). "Resolving the internal and basal geometry of ice masses using imaging phase-sensitive radar". Journal of Glaciology. 64 (246): 649–660. Bibcode:2018JGlac..64..649Y. doi: 10.1017/jog.2018.54 . ISSN   0022-1430.
  41. ↑ Gillet-Chaulet, F.; Hindmarsh, R.C.A.; Corr, H.F.J.; King, E.C.; Jenkins, A. (2011). "In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar". Geophysical Research Letters . 38 (24): n/a. Bibcode:2011GeoRL..3824503G. doi: 10.1029/2011GL049843 .
  42. ↑ Kingslake, Jonathan; Hindmarsh, Richard C. A.; Aðalgeirsdóttir, Guðfinna; Conway, Howard; Corr, Hugh F. J.; Gillet-Chaulet, Fabien; Martín, Carlos; King, Edward C.; Mulvaney, Robert; Pritchard, Hamish D. (2014). "Full-depth englacial vertical ice sheet velocities measured using phase-sensitive radar". Journal of Geophysical Research: Earth Surface. 119 (12): 2604–2618. Bibcode:2014JGRF..119.2604K. doi: 10.1002/2014JF003275 . ISSN   2169-9011.
  43. ↑ Castelletti, D.; Schroeder, D. M.; Jordan, T. M.; Young, D. (2020). "Permanent Scatterers in Repeat-Pass Airborne VHF Radar Sounder for Layer-Velocity Estimation". IEEE Geoscience and Remote Sensing Letters. 18 (10): 1766–1770. doi: 10.1109/LGRS.2020.3007514 . hdl: 1983/f3fa4214-5e2f-4bc4-9591-adb549db9cd4 . ISSN   1558-0571.
  44. ↑ Arcone, Steven A.; Lever, James H.; Ray, Laura E.; Walker, Benjamin S.; Hamilton, Gordon; Kaluzienski, Lynn (2016-01-01). "Ground-penetrating radar profiles of the McMurdo Shear Zone, Antarctica, acquired with an unmanned rover: Interpretation of crevasses, fractures, and folds within firn and marine ice". Geophysics. 81 (1): WA21 –WA34. Bibcode:2016Geop...81A..21A. doi:10.1190/geo2015-0132.1. ISSN   0016-8033.
  45. ↑ Bagshaw, E. A.; Lishman, B.; Wadham, J. L.; Bowden, J. A.; Burrow, S. G.; Clare, L. R.; Chandler, D. (2014). "Novel wireless sensors for in situ measurement of sub-ice hydrologic systems". Annals of Glaciology. 55 (65): 41–50. Bibcode:2014AnGla..55...41B. doi: 10.3189/2014AoG65A007 . ISSN   0260-3055.
  46. ↑ Mingo, Laurent; Flowers, Gwenn E.; Crawford, Anna J.; Mueller, Derek R.; Bigelow, David G. (April 2020). "A stationary impulse-radar system for autonomous deployment in cold and temperate environments". Annals of Glaciology. 61 (81): 99–107. Bibcode:2020AnGla..61...99M. doi: 10.1017/aog.2020.2 . hdl: 10023/19604 . ISSN   0260-3055.
  47. ↑ Liu, Peng; Mendoza, Jesus; Hu, Hanxiong; Burkett, Peter G.; Urbina, Julio V.; Anandakrishnan, Sridhar; Bilen, Sven G. (March 2019). "Software-Defined Radar Systems for Polar Ice-Sheet Research". IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 12 (3): 803–820. Bibcode:2019IJSTA..12..803L. doi: 10.1109/JSTARS.2019.2895616 . ISSN   1939-1404.
  48. ↑ Peters, Sean T.; Schroeder, Dustin M.; Castelletti, Davide; Haynes, Mark; Romero-Wolf, Andrew (December 2018). "In Situ Demonstration of a Passive Radio Sounding Approach Using the Sun for Echo Detection". IEEE Transactions on Geoscience and Remote Sensing. 56 (12): 7338–7349. Bibcode:2018ITGRS..56.7338P. doi: 10.1109/TGRS.2018.2850662 . ISSN   0196-2892.
  49. ↑ Romero-Wolf, Andrew; Vance, Steve; Maiwald, Frank; Heggy, Essam; Ries, Paul; Liewer, Kurt (2015-03-01). "A passive probe for subsurface oceans and liquid water in Jupiter's icy moons". Icarus. 248: 463–477. arXiv: 1404.1876 . Bibcode:2015Icar..248..463R. doi:10.1016/j.icarus.2014.10.043. ISSN   0019-1035. S2CID   119234268.
  50. ↑ Bamber, J. L.; Griggs, J. A.; Hurkmans, R. T. W. L.; Dowdeswell, J. A.; Gogineni, S. P.; Howat, I.; Mouginot, J.; Paden, J.; Palmer, S.; Rignot, E.; Steinhage, D. (2013-03-22). "A new bed elevation dataset for Greenland". The Cryosphere. 7 (2): 499–510. Bibcode:2013TCry....7..499B. doi: 10.5194/tc-7-499-2013 . hdl: 1808/18762 . ISSN   1994-0416.
  51. ↑ MacKie, E. J.; Schroeder, D. M.; Caers, J.; Siegfried, M. R.; Scheidt, C. (2020). "Antarctic Topographic Realizations and Geostatistical Modeling Used to Map Subglacial Lakes". Journal of Geophysical Research: Earth Surface. 125 (3): e2019JF005420. Bibcode:2020JGRF..12505420M. doi: 10.1029/2019JF005420 . ISSN   2169-9011.
  52. ↑ Morlighem, M.; Rignot, E.; Seroussi, H.; Larour, E.; Dhia, H. Ben; Aubry, D. (2011). "A mass conservation approach for mapping glacier ice thickness". Geophysical Research Letters. 38 (19): n/a. Bibcode:2011GeoRL..3819503M. doi: 10.1029/2011GL048659 . ISSN   1944-8007.
  53. ↑ Bo, Sun; Siegert, Martin J.; Mudd, Simon M.; Sugden, David; Fujita, Shuji; Xiangbin, Cui; Yunyun, Jiang; Xueyuan, Tang; Yuansheng, Li (June 2009). "The Gamburtsev mountains and the origin and early evolution of the Antarctic Ice Sheet". Nature. 459 (7247): 690–693. Bibcode:2009Natur.459..690B. doi:10.1038/nature08024. ISSN   1476-4687. PMID   19494912. S2CID   4381263.
  54. ↑ King, Edward C. (April 2020). "The precision of radar-derived subglacial bed topography: a case study from Pine Island Glacier, Antarctica". Annals of Glaciology. 61 (81): 154–161. Bibcode:2020AnGla..61..154K. doi: 10.1017/aog.2020.33 . ISSN   0260-3055.
  55. ↑ Ross, Neil; Bingham, Robert G.; Corr, Hugh F. J.; Ferraccioli, Fausto; Jordan, Tom A.; Le Brocq, Anne; Rippin, David M.; Young, Duncan; Blankenship, Donald D.; Siegert, Martin J. (June 2012). "Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica". Nature Geoscience. 5 (6): 393–396. Bibcode:2012NatGe...5..393R. doi:10.1038/ngeo1468. ISSN   1752-0894.
  56. ↑ Vaughan, David G.; Corr, Hugh F. J.; Ferraccioli, Fausto; Frearson, Nicholas; O'Hare, Aidan; Mach, Dieter; Holt, John W.; Blankenship, Donald D.; Morse, David L.; Young, Duncan A. (2006). "New boundary conditions for the West Antarctic ice sheet: Subglacial topography beneath Pine Island Glacier". Geophysical Research Letters. 33 (9): L09501. Bibcode:2006GeoRL..33.9501V. doi:10.1029/2005GL025588. ISSN   1944-8007. S2CID   128406976.
  57. ↑ Young, Duncan A.; Wright, Andrew P.; Roberts, Jason L.; Warner, Roland C.; Young, Neal W.; Greenbaum, Jamin S.; Schroeder, Dustin M.; Holt, John W.; Sugden, David E.; Blankenship, Donald D.; van Ommen, Tas D. (June 2011). "A dynamic early East Antarctic Ice Sheet suggested by ice-covered fjord landscapes". Nature. 474 (7349): 72–75. Bibcode:2011Natur.474...72Y. doi:10.1038/nature10114. ISSN   1476-4687. PMID   21637255. S2CID   4425075.
  58. ↑ Clarke, G. K. C.; Cross, G. M.; Benson, C. S. (1987). "Airborne UHF Radar Measurements of Caldera Geometry and Volcanic History, Mount Wrangell, Alaska, U.S.A." Annals of Glaciology. 9: 236–237. Bibcode:1987AnGla...9R.236C. doi: 10.3189/S0260305500000707 . ISSN   0260-3055.
  59. ↑ Flowers, Gwenn E.; Clarke, Garry K. C. (1999). "Surface and bed topography of Trapridge Glacier, Yukon Territory, Canada: digital elevation models and derived hydraulic geometry". Journal of Glaciology. 45 (149): 165–174. doi: 10.3189/S0022143000003142 . ISSN   0022-1430.
  60. ↑ Maurer, Hansruedi; Hauck, Christian (2007). "Geophysical imaging of alpine rock glaciers". Journal of Glaciology. 53 (180): 110–120. Bibcode:2007JGlac..53..110M. doi: 10.3189/172756507781833893 . ISSN   0022-1430.
  61. ↑ Zamora, Rodrigo; Ulloa, David; Garcia, Gonzalo; Mella, Ronald; Uribe, José; Wendt, Jens; Rivera, Andrés; Gacitúa, Guisella; Casassa, Gino (2009). "Airborne radar sounder for temperate ice: initial results from Patagonia". Journal of Glaciology. 55 (191): 507–512. Bibcode:2009JGlac..55..507Z. doi: 10.3189/002214309788816641 . ISSN   0022-1430.
  62. ↑ Jacobel, Robert W.; Welch, Brian C.; Osterhouse, David; Pettersson, Rickard; MacGregor, Joseph A. (2009). "Spatial variation of radar-derived basal conditions on Kamb Ice Stream, West Antarctica". Annals of Glaciology. 50 (51): 10–16. Bibcode:2009AnGla..50...10J. doi: 10.3189/172756409789097504 . ISSN   0260-3055.
  63. ↑ Matsuoka, Kenichi (2011-03-16). "Pitfalls in radar diagnosis of ice-sheet bed conditions: Lessons from englacial attenuation models: RADAR DIAGNOSIS OF ICE-SHEET BEDS". Geophysical Research Letters. 38 (5): n/a. doi: 10.1029/2010GL046205 .
  64. ↑ Pettinelli, Elena; Cosciotti, Barbara; Di Paolo, Federico; Lauro, Sebastian Emanuel; Mattei, Elisabetta; Orosei, Roberto; Vannaroni, Giuliano (September 2015). "Dielectric properties of Jovian satellite ice analogs for subsurface radar exploration: A review: JOVIAN ICY MOONS DIELECTRIC PROPERTIES". Reviews of Geophysics. 53 (3): 593–641. doi:10.1002/2014RG000463. hdl: 11590/283398 . S2CID   128925940.
  65. ↑ Stillman, David E.; MacGregor, Joseph A.; Grimm, Robert E. (March 2013). "The role of acids in electrical conduction through ice: CONDUCTION OF ACIDS IN ICE". Journal of Geophysical Research: Earth Surface. 118 (1): 1–16. doi: 10.1029/2012JF002603 .
  66. ↑ Muto, Atsuhiro; Alley, Richard B.; Parizek, Byron R.; Anandakrishnan, Sridhar (December 2019). "Bed-type variability and till (dis)continuity beneath Thwaites Glacier, West Antarctica". Annals of Glaciology. 60 (80): 82–90. Bibcode:2019AnGla..60...82M. doi: 10.1017/aog.2019.32 . ISSN   0260-3055.
  67. ↑ Rippin, D.M.; Bingham, R.G.; Jordan, T.A.; Wright, A.P.; Ross, N.; Corr, H.F.J.; Ferraccioli, F.; Le Brocq, A.M.; Rose, K.C.; Siegert, M.J. (June 2014). "Basal roughness of the Institute and Möller Ice Streams, West Antarctica: Process determination and landscape interpretation". Geomorphology. 214: 139–147. Bibcode:2014Geomo.214..139R. doi: 10.1016/j.geomorph.2014.01.021 . hdl: 20.500.11820/8da22cbd-e80b-4989-bd2c-477ae6a8463c .
  68. ↑ Попов, С. В. (2017-04-18). "Flow-Lines Computation and Their Use in Subglacial Geomorphology and Glacial Erosion Modeling: The Princess Elizabeth Land (East Antarctica) Case Study". Geomorphology Ras (in Russian) (1): 46–54. doi: 10.15356/0435-4281-2017-1-46-54 . Retrieved 2021-03-04.
  69. ↑ Fujita, Shuji; Maeno, Hideo; Uratsuka, Seiho; Furukawa, Teruo; Mae, Shinji; Fujii, Yoshiyuki; Watanabe, Okitsugu (1999). "Nature of radio echo layering in the Antarctic Ice Sheet detected by a two-frequency experiment". Journal of Geophysical Research: Solid Earth. 104 (B6): 13013–13024. Bibcode:1999JGR...10413013F. doi: 10.1029/1999JB900034 . ISSN   2156-2202.
  70. ↑ Campbell, Seth; Balco, Greg; Todd, Claire; Conway, Howard; Huybers, Kathleen; Simmons, Christopher; Vermeulen, Michael (2013). "Radar-detected englacial stratigraphy in the Pensacola Mountains, Antarctica: implications for recent changes in ice flow and accumulation". Annals of Glaciology. 54 (63): 91–100. Bibcode:2013AnGla..54...91C. doi: 10.3189/2013AoG63A371 . ISSN   0260-3055.
  71. ↑ NEEM community members (January 2013). "Eemian interglacial reconstructed from a Greenland folded ice core". Nature. 493 (7433): 489–494. Bibcode:2013Natur.493..489N. doi:10.1038/nature11789. hdl: 21.11116/0000-0006-BC16-E . ISSN   0028-0836. PMID   23344358. S2CID   4420908.
  72. ↑ Hindmarsh, Richard C. A.; Leysinger Vieli, Gwendolyn J.-M. C.; Raymond, Mélanie J.; Gudmundsson, G. Hilmar (2006). "Draping or overriding: The effect of horizontal stress gradients on internal layer architecture in ice sheets". Journal of Geophysical Research. 111 (F2): F02018. Bibcode:2006JGRF..111.2018H. doi:10.1029/2005JF000309. ISSN   0148-0227. S2CID   21709437.
  73. ↑ Karlsson, Nanna B.; Binder, Tobias; Eagles, Graeme; Helm, Veit; Pattyn, Frank; Van Liefferinge, Brice; Eisen, Olaf (2018-07-25). "Glaciological characteristics in the Dome Fuji region and new assessment for "Oldest Ice"". The Cryosphere. 12 (7): 2413–2424. Bibcode:2018TCry...12.2413K. doi: 10.5194/tc-12-2413-2018 . ISSN   1994-0424.
  74. ↑ MacGregor, Joseph A.; Fahnestock, Mark A.; Catania, Ginny A.; Paden, John D.; Prasad Gogineni, S.; Young, S. Keith; Rybarski, Susan C.; Mabrey, Alexandria N.; Wagman, Benjamin M.; Morlighem, Mathieu (February 2015). "Radiostratigraphy and age structure of the Greenland Ice Sheet". Journal of Geophysical Research: Earth Surface. 120 (2): 212–241. Bibcode:2015JGRF..120..212M. doi:10.1002/2014JF003215. ISSN   2169-9003. PMC   4508962 . PMID   26213664.
  75. ↑ Cavitte, Marie G. P.; Parrenin, Frédéric; Ritz, Catherine; Young, Duncan A.; Van Liefferinge, Brice; Blankenship, Donald D.; Frezzotti, Massimo; Roberts, Jason L. (2018-04-17). "Accumulation patterns around Dome C, East Antarctica, in the last 73 kyr". The Cryosphere. 12 (4): 1401–1414. Bibcode:2018TCry...12.1401C. doi: 10.5194/tc-12-1401-2018 . ISSN   1994-0424.
  76. ↑ Kohler, Jack; Moore, John; Kennett, Mike; Engeset, Rune; Elvehøy, Hallgeir (1997). "Using ground-penetrating radar to image previous years' summer surfaces for mass-balance measurements". Annals of Glaciology. 24: 355–360. Bibcode:1997AnGla..24..355K. doi: 10.3189/S0260305500012441 . ISSN   0260-3055.
  77. ↑ Koutnik, Michelle R.; Fudge, T. J.; Conway, Howard; Waddington, Edwin D.; Neumann, Thomas A.; Cuffey, Kurt M.; Buizert, Christo; Taylor, Kendrick C. (2016). "Holocene accumulation and ice flow near the West Antarctic Ice Sheet Divide ice core site". Journal of Geophysical Research: Earth Surface. 121 (5): 907–924. Bibcode:2016JGRF..121..907K. doi: 10.1002/2015JF003668 . ISSN   2169-9011.
  78. ↑ Medley, B.; Joughin, I.; Smith, B. E.; Das, S. B.; Steig, E. J.; Conway, H.; Gogineni, S.; Lewis, C.; Criscitiello, A. S.; McConnell, J. R.; van den Broeke, M. R. (2014-07-31). "Constraining the recent mass balance of Pine Island and Thwaites glaciers, West Antarctica, with airborne observations of snow accumulation". The Cryosphere. 8 (4): 1375–1392. Bibcode:2014TCry....8.1375M. doi: 10.5194/tc-8-1375-2014 . hdl: 1808/18740 . ISSN   1994-0424.
  79. ↑ Waddington, Edwin D.; Neumann, Thomas A.; Koutnik, Michelle R.; Marshall, Hans-Peter; Morse, David L. (2007). "Inference of accumulation-rate patterns from deep layers in glaciers and ice sheets". Journal of Glaciology. 53 (183): 694–712. Bibcode:2007JGlac..53..694W. doi: 10.3189/002214307784409351 . ISSN   0022-1430.
  80. ↑ Eisen, Olaf (2008). "Inference of velocity pattern from isochronous layers in firn, using an inverse method". Journal of Glaciology. 54 (187): 613–630. Bibcode:2008JGlac..54..613E. doi: 10.3189/002214308786570818 . ISSN   0022-1430.
  81. ↑ Fahnestock, Mark; Abdalati, Waleed; Joughin, Ian; Brozena, John; Gogineni, Prasad (2001-12-14). "High Geothermal Heat Flow, Basal Melt, and the Origin of Rapid Ice Flow in Central Greenland". Science. 294 (5550): 2338–2342. Bibcode:2001Sci...294.2338F. doi:10.1126/science.1065370. ISSN   0036-8075. PMID   11743197. S2CID   19844250.
  82. ↑ Vieli, G. J.-M. C. Leysinger; Hindmarsh, R. C. A.; Siegert, M. J. (2007). "Three-dimensional flow influences on radar layer stratigraphy". Annals of Glaciology. 46 (1): 22–28. Bibcode:2007AnGla..46...22L. doi: 10.3189/172756407782871729 . ISSN   0260-3055.
  83. ↑ Pettit, Erin C.; Waddington, Edwin D.; Harrison, William D.; Thorsteinsson, Throstur; Elsberg, Daniel; Morack, John; Zumberge, Mark A. (2011). "The crossover stress, anisotropy and the ice flow law at Siple Dome, West Antarctica". Journal of Glaciology. 57 (201): 39–52. Bibcode:2011JGlac..57...39P. doi: 10.3189/002214311795306619 . ISSN   0022-1430.
  84. ↑ Jordan, Thomas M.; Schroeder, Dustin M.; Castelletti, Davide; Li, Jilu; Dall, Jorgen (November 2019). "A Polarimetric Coherence Method to Determine Ice Crystal Orientation Fabric From Radar Sounding: Application to the NEEM Ice Core Region". IEEE Transactions on Geoscience and Remote Sensing. 57 (11): 8641–8657. Bibcode:2019ITGRS..57.8641J. doi:10.1109/TGRS.2019.2921980. ISSN   0196-2892. S2CID   198442821.
  85. ↑ Martín, Carlos; Gudmundsson, G. Hilmar; Pritchard, Hamish D.; Gagliardini, Olivier (2009-10-14). "On the effects of anisotropic rheology on ice flow, internal structure, and the age-depth relationship at ice divides". Journal of Geophysical Research. 114 (F4): F04001. Bibcode:2009JGRF..114.4001M. doi:10.1029/2008JF001204. ISSN   0148-0227. S2CID   129357387.
  86. ↑ Bell, R. E.; Ferraccioli, F.; Creyts, T. T.; Braaten, D.; Corr, H.; Das, I.; Damaske, D.; Frearson, N.; Jordan, T.; Rose, K.; Studinger, M. (2011-03-25). "Widespread Persistent Thickening of the East Antarctic Ice Sheet by Freezing from the Base". Science. 331 (6024): 1592–1595. Bibcode:2011Sci...331.1592B. doi:10.1126/science.1200109. ISSN   0036-8075. PMID   21385719. S2CID   45110037.
  87. ↑ Drews, R.; Eisen, O.; Weikusat, I.; Kipfstuhl, S.; Lambrecht, A.; Steinhage, D.; Wilhelms, F.; Miller, H. (2009-08-25). "Layer disturbances and the radio-echo free zone in ice sheets". The Cryosphere. 3 (2): 195–203. Bibcode:2009TCry....3..195D. doi: 10.5194/tc-3-195-2009 . ISSN   1994-0416.
  88. ↑ Winter, Kate; Woodward, John; Ross, Neil; Dunning, Stuart A.; Hein, Andrew S.; Westoby, Matthew J.; Culberg, Riley; Marrero, Shasta M.; Schroeder, Dustin M.; Sugden, David E.; Siegert, Martin J. (2019). "Radar-Detected Englacial Debris in the West Antarctic Ice Sheet". Geophysical Research Letters. 46 (17–18): 10454–10462. Bibcode:2019GeoRL..4610454W. doi: 10.1029/2019GL084012 . hdl: 10044/1/72891 . ISSN   1944-8007.
  89. ↑ Carter, Sasha P.; Blankenship, Donald D.; Peters, Matthew E.; Young, Duncan A.; Holt, John W.; Morse, David L. (March 2007). "Radar-based subglacial lake classification in Antarctica: ANTARCTIC SUBGLACIAL LAKES". Geochemistry, Geophysics, Geosystems. 8 (3): n/a. doi: 10.1029/2006GC001408 . S2CID   134827447.
  90. ↑ Ilisei, Ana-Maria; Khodadadzadeh, Mahdi; Ferro, Adamo; Bruzzone, Lorenzo (June 2019). "An Automatic Method for Subglacial Lake Detection in Ice Sheet Radar Sounder Data". IEEE Transactions on Geoscience and Remote Sensing. 57 (6): 3252–3270. Bibcode:2019ITGRS..57.3252I. doi:10.1109/TGRS.2018.2882911. ISSN   0196-2892. S2CID   127129493.
  91. ↑ Oswald, G. K. A.; Robin, G. De Q. (October 1973). "Lakes Beneath the Antarctic Ice Sheet". Nature. 245 (5423): 251–254. Bibcode:1973Natur.245..251O. doi:10.1038/245251a0. ISSN   0028-0836. S2CID   4271414.
  92. ↑ Palmer, Steven J.; Dowdeswell, Julian A.; Christoffersen, Poul; Young, Duncan A.; Blankenship, Donald D.; Greenbaum, Jamin S.; Benham, Toby; Bamber, Jonathan; Siegert, Martin J. (2013). "Greenland subglacial lakes detected by radar". Geophysical Research Letters. 40 (23): 6154–6159. Bibcode:2013GeoRL..40.6154P. doi: 10.1002/2013GL058383 . hdl: 10871/30231 . ISSN   1944-8007.
  93. ↑ Rutishauser, Anja; Blankenship, Donald D.; Sharp, Martin; Skidmore, Mark L.; Greenbaum, Jamin S.; Grima, Cyril; Schroeder, Dustin M.; Dowdeswell, Julian A.; Young, Duncan A. (2018-04-01). "Discovery of a hypersaline subglacial lake complex beneath Devon Ice Cap, Canadian Arctic". Science Advances. 4 (4): eaar4353. Bibcode:2018SciA....4.4353R. doi:10.1126/sciadv.aar4353. ISSN   2375-2548. PMC   5895444 . PMID   29651462.
  94. ↑ Siegert, Martin J. (2018). "A 60-year international history of Antarctic subglacial lake exploration". Geological Society, London, Special Publications. 461 (1): 7–21. Bibcode:2018GSLSP.461....7S. doi: 10.1144/SP461.5 . ISSN   0305-8719.
  95. ↑ Wolovick, Michael J.; Bell, Robin E.; Creyts, Timothy T.; Frearson, Nicholas (2013). "Identification and control of subglacial water networks under Dome A, Antarctica". Journal of Geophysical Research: Earth Surface. 118 (1): 140–154. Bibcode:2013JGRF..118..140W. doi:10.1029/2012JF002555. ISSN   2169-9011. S2CID   31518000.
  96. ↑ Björnsson, Helgi; Gjessing, Yngvar; Hamran, Svein-Erik; Hagen, Jon Ove; LiestøL, Olav; Pálsson, Finnur; Erlingsson, Björn (1996). "The thermal regime of sub-polar glaciers mapped by multi-frequency radio-echo sounding". Journal of Glaciology. 42 (140): 23–32. doi: 10.3189/S0022143000030495 . ISSN   0022-1430.
  97. ↑ Bradford, John H.; Harper, Joel T. (2005). "Wave field migration as a tool for estimating spatially continuous radar velocity and water content in glaciers". Geophysical Research Letters. 32 (8): L08502. Bibcode:2005GeoRL..32.8502B. doi: 10.1029/2004GL021770 . ISSN   1944-8007.
  98. ↑ Murray, Tavi; Stuart, Graham W.; Fry, Matt; Gamble, Nicola H.; Crabtree, Mike D. (2000). "Englacial water distribution in a temperate glacier from surface and borehole radar velocity analysis". Journal of Glaciology. 46 (154): 389–398. Bibcode:2000JGlac..46..389M. doi: 10.3189/172756500781833188 . ISSN   0022-1430.
  99. ↑ Forster, Richard R.; Box, Jason E.; van den Broeke, Michiel R.; Miège, Clément; Burgess, Evan W.; van Angelen, Jan H.; Lenaerts, Jan T. M.; Koenig, Lora S.; Paden, John; Lewis, Cameron; Gogineni, S. Prasad (February 2014). "Extensive liquid meltwater storage in firn within the Greenland ice sheet". Nature Geoscience. 7 (2): 95–98. Bibcode:2014NatGe...7...95F. doi:10.1038/ngeo2043. ISSN   1752-0908. S2CID   128970359.
  100. ↑ Chu, W.; Schroeder, D. M.; Siegfried, M. R. (2018-11-16). "Retrieval of Englacial Firn Aquifer Thickness From Ice-Penetrating Radar Sounding in Southeastern Greenland". Geophysical Research Letters. 45 (21): 11, 770–11, 778. Bibcode:2018GeoRL..4511770C. doi: 10.1029/2018GL079751 .
  101. ↑ Kulessa, B.; Booth, A. D.; Hobbs, A.; Hubbard, A. L. (2008). "Automated monitoring of subglacial hydrological processes with ground-penetrating radar (GPR) at high temporal resolution: scope and potential pitfalls". Geophysical Research Letters. 35 (24): L24502. Bibcode:2008GeoRL..3524502K. doi: 10.1029/2008GL035855 . hdl: 2160/7032 . ISSN   1944-8007.
  102. ↑ Catania, G. A.; Conway, H.; Raymond, C. F.; Scambos, T. A. (2006). "Evidence for floatation or near floatation in the mouth of Kamb Ice Stream, West Antarctica, prior to stagnation". Journal of Geophysical Research: Earth Surface. 111 (F1): F01005. Bibcode:2006JGRF..111.1005C. doi: 10.1029/2005JF000355 . ISSN   2156-2202.
  103. ↑ Greenbaum, J. S.; Blankenship, D. D.; Young, D. A.; Richter, T. G.; Roberts, J. L.; Aitken, A. R. A.; Legresy, B.; Schroeder, D. M.; Warner, R. C.; van Ommen, T. D.; Siegert, M. J. (April 2015). "Ocean access to a cavity beneath Totten Glacier in East Antarctica". Nature Geoscience. 8 (4): 294–298. Bibcode:2015NatGe...8..294G. doi:10.1038/ngeo2388. ISSN   1752-0894.
  104. ↑ Khazendar, Ala; Rignot, Eric; Schroeder, Dustin M.; Seroussi, Helene; Schodlok, Michael P.; Scheuchl, Bernd; Mouginot, Jeremie; Sutterley, Tyler C.; Velicogna, Isabella (December 2016). "Rapid submarine ice melting in the grounding zones of ice shelves in West Antarctica". Nature Communications. 7 (1): 13243. Bibcode:2016NatCo...713243K. doi:10.1038/ncomms13243. ISSN   2041-1723. PMC   5093338 . PMID   27780191.
  105. ↑ Pattyn, F.; Matsuoka, K.; Callens, D.; Conway, H.; Depoorter, M.; Docquier, D.; Hubbard, B.; Samyn, D.; Tison, J. L. (2012). "Melting and refreezing beneath Roi Baudouin Ice Shelf (East Antarctica) inferred from radar, GPS, and ice core data". Journal of Geophysical Research: Earth Surface. 117 (F4): n/a. Bibcode:2012JGRF..117.4008P. doi: 10.1029/2011JF002154 . hdl: 1983/ec278bf6-949a-441d-be03-007ac7e5611b . ISSN   2156-2202.
  106. ↑ Grima, Cyril; Greenbaum, Jamin S.; Lopez Garcia, Erika J.; Soderlund, Krista M.; Rosales, Arami; Blankenship, Donald D.; Young, Duncan A. (2016-07-16). "Radar detection of the brine extent at McMurdo Ice Shelf, Antarctica, and its control by snow accumulation: BRINE EXTENT AT MCMURDO ICE SHELF". Geophysical Research Letters. 43 (13): 7011–7018. doi: 10.1002/2016GL069524 .
  107. ↑ Le Brocq, Anne M.; Ross, Neil; Griggs, Jennifer A.; Bingham, Robert G.; Corr, Hugh F. J.; Ferraccioli, Fausto; Jenkins, Adrian; Jordan, Tom A.; Payne, Antony J.; Rippin, David M.; Siegert, Martin J. (November 2013). "Evidence from ice shelves for channelized meltwater flow beneath the Antarctic Ice Sheet". Nature Geoscience. 6 (11): 945–948. Bibcode:2013NatGe...6..945L. doi:10.1038/ngeo1977. ISSN   1752-0894.
  108. ↑ Campbell, Bruce A.; Schroeder, Dustin M.; Whitten, Jennifer L. (January 2018). "Mars radar clutter and surface roughness characteristics from MARSIS data". Icarus. 299: 22–30. Bibcode:2018Icar..299...22C. doi:10.1016/j.icarus.2017.07.011.
  109. ↑ Holt, John W.; Safaeinili, Ali; Plaut, Jeffrey J.; Head, James W.; Phillips, Roger J.; Seu, Roberto; Kempf, Scott D.; Choudhary, Prateek; Young, Duncan A.; Putzig, Nathaniel E.; Biccari, Daniela (2008-11-21). "Radar Sounding Evidence for Buried Glaciers in the Southern Mid-Latitudes of Mars". Science. 322 (5905): 1235–1238. Bibcode:2008Sci...322.1235H. doi:10.1126/science.1164246. ISSN   0036-8075. PMID   19023078. S2CID   36614186.
  110. ↑ Lalich, D. E.; Holt, J. W. (2017-01-28). "New Martian climate constraints from radar reflectivity within the north polar layered deposits". Geophysical Research Letters. 44 (2): 657–664. Bibcode:2017GeoRL..44..657L. doi: 10.1002/2016GL071323 . ISSN   0094-8276.
  111. ↑ Lauro, Sebastian Emanuel; Pettinelli, Elena; Caprarelli, Graziella; Guallini, Luca; Rossi, Angelo Pio; Mattei, Elisabetta; Cosciotti, Barbara; Cicchetti, Andrea; Soldovieri, Francesco; Cartacci, Marco; Di Paolo, Federico (January 2021). "Multiple subglacial water bodies below the south pole of Mars unveiled by new MARSIS data". Nature Astronomy. 5 (1): 63–70. arXiv: 2010.00870 . Bibcode:2021NatAs...5...63L. doi:10.1038/s41550-020-1200-6. ISSN   2397-3366. S2CID   222125007.
  112. ↑ Nerozzi, Stefano; W. Holt, John (July 2018). "Earliest accumulation history of the north polar layered deposits, Mars from SHARAD". Icarus. 308: 128–137. Bibcode:2018Icar..308..128N. doi:10.1016/j.icarus.2017.05.027. S2CID   125836984.
  113. ↑ Orosei, R.; Lauro, S. E.; Pettinelli, E.; Cicchetti, A.; Coradini, M.; Cosciotti, B.; Paolo, F. Di; Flamini, E.; Mattei, E.; Pajola, M.; Soldovieri, F. (2018-08-03). "Radar evidence of subglacial liquid water on Mars". Science. 361 (6401): 490–493. arXiv: 2004.04587 . Bibcode:2018Sci...361..490O. doi: 10.1126/science.aar7268 . ISSN   0036-8075. PMID   30045881.
  114. ↑ Plaut, Jeffrey J.; Safaeinili, Ali; Holt, John W.; Phillips, Roger J.; Head, James W.; Seu, Roberto; Putzig, Nathaniel E.; Frigeri, Alessandro (2009). "Radar evidence for ice in lobate debris aprons in the mid-northern latitudes of Mars". Geophysical Research Letters. 36 (2): n/a. Bibcode:2009GeoRL..36.2203P. doi: 10.1029/2008GL036379 . ISSN   1944-8007. S2CID   17530607.
  115. ↑ Putzig, Nathaniel E.; Smith, Isaac B.; Perry, Matthew R.; Foss, Frederick J.; Campbell, Bruce A.; Phillips, Roger J.; Seu, Roberto (2018-07-01). "Three-dimensional radar imaging of structures and craters in the Martian polar caps". Icarus. Mars Polar Science VI. 308: 138–147. Bibcode:2018Icar..308..138P. doi:10.1016/j.icarus.2017.09.023. ISSN   0019-1035. PMC   5937288 . PMID   29749975.
  116. ↑ Seu, Roberto; Phillips, Roger J.; Biccari, Daniela; Orosei, Roberto; Masdea, Arturo; Picardi, Giovanni; Safaeinili, Ali; Campbell, Bruce A.; Plaut, Jeffrey J.; Marinangeli, Lucia; Smrekar, Suzanne E. (2007). "SHARAD sounding radar on the Mars Reconnaissance Orbiter". Journal of Geophysical Research: Planets. 112 (E5): E05S05. Bibcode:2007JGRE..112.5S05S. doi: 10.1029/2006JE002745 . ISSN   2156-2202.
  117. ↑ Smith, I. B.; Putzig, N. E.; Holt, J. W.; Phillips, R. J. (2016-05-27). "An ice age recorded in the polar deposits of Mars". Science. 352 (6289): 1075–1078. Bibcode:2016Sci...352.1075S. doi: 10.1126/science.aad6968 . ISSN   0036-8075. PMID   27230372.
  118. ↑ Bruzzone, L.; Alberti, G.; Catallo, C.; Ferro, A.; Kofman, W.; Orosei, R. (May 2011). "Subsurface Radar Sounding of the Jovian Moon Ganymede". Proceedings of the IEEE. 99 (5): 837–857. doi:10.1109/JPROC.2011.2108990. ISSN   1558-2256. S2CID   12738030.
  119. ↑ Heggy, Essam; Scabbia, Giovanni; Bruzzone, Lorenzo; Pappalardo, Robert T. (March 2017). "Radar probing of Jovian icy moons: Understanding subsurface water and structure detectability in the JUICE and Europa missions". Icarus. 285: 237–251. Bibcode:2017Icar..285..237H. doi:10.1016/j.icarus.2016.11.039.
  120. ↑ McKinnon, W (2005). "Radar sounding of convecting ice shells in the presence of convection: application to Europa, Ganymede, and Callisto". Workshop on Radar Investigations of Planetary and Terrestrial Environments, Houston, TX: 53. Bibcode:2005ript.work...53M.
  121. ↑ Scanlan, Kirk M.; Grima, Cyril; Steinbrügge, Gregor; Kempf, Scott D.; Young, Duncan A.; Blankenship, Donald D. (2019-11-15). "Geometric determination of ionospheric total electron content from dual frequency radar sounding measurements". Planetary and Space Science. 178: 104696. Bibcode:2019P&SS..17804696S. doi:10.1016/j.pss.2019.07.010. ISSN   0032-0633. S2CID   199677922.
  122. ↑ Schmidt, B. E.; Blankenship, D. D.; Patterson, G. W.; Schenk, P. M. (November 2011). "Active formation of 'chaos terrain' over shallow subsurface water on Europa". Nature. 479 (7374): 502–505. Bibcode:2011Natur.479..502S. doi:10.1038/nature10608. ISSN   0028-0836. PMID   22089135. S2CID   4405195.
  123. ↑ Steinbrügge, G.; Schroeder, D. M.; Haynes, M. S.; Hussmann, H.; Grima, C.; Blankenship, D. D. (2018-01-15). "Assessing the potential for measuring Europa's tidal Love number h2 using radar sounder and topographic imager data". Earth and Planetary Science Letters. 482: 334–341. Bibcode:2018E&PSL.482..334S. doi:10.1016/j.epsl.2017.11.028. ISSN   0012-821X.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.