Radio-Echo Sounding: Glaciological Interpretations and Applications

Robin, G. de Q.

doi:10.3189/s0022143000034262

Cited by 22 publications

(19 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To investigate subsurface properties of the large ice masses, radar sounding techniques have been used for several decades at frequencies between a few and several hundred megahertz as a powerful tool [Bogorodskiy et al, 1985;Robin et al, 1969]. Reflections of radio waves from within the ice are caused by sudden changes in complex dielectric permittivity of layers in the ice sheets.…”

Section: Introductionmentioning

confidence: 99%

Nature of radio echo layering in the Antarctic Ice Sheet detected by a two‐frequency experiment

Fujita¹,

Maeno²,

Uratsuka³

et al. 1999

J. Geophys. Res.

194

259

View full text Add to dashboard Cite

Abstract. A two-frequency radio echo sounding experiment was carried out at Dome Fuji, the second highest dome in East Antarctica, and along a 1150-km-long traverse line from the dome to the coast. The goal was to determine the dominant causes of the radio echo internal reflections and to investigate their possible changes with depth ranges and regions. From the two-frequency (60 MHz and 179 MHz) radio echo responses at various sites, we distinguished four zones. Each of the zones is characterized by a dominant cause of radio echo internal reflection as follows. In the "PD" zone, changes in dielectric permittivity are mainly due to density fluctuations; in the "PcoF" zone, changes in dielectric permittivity are mainly due to changes in crystal-orientation fabrics; and in the "CA" zone, changes in electrical conductivity are mainly due to changes in acidity induced by past volcanic eruptions. In each of these three zones, the changes occur commonly along isochrones. In addition, a basal echo-free zone, the fourth zone, was found to appear always below the PCOF zone. These four zones and their distribution suggested variations of the physical conditions within the ice sheet.

show abstract

Section: Introductionmentioning

confidence: 99%

Nature of radio echo layering in the Antarctic Ice Sheet detected by a two‐frequency experiment

Fujita¹,

Maeno²,

Uratsuka³

et al. 1999

J. Geophys. Res.

194

259

View full text Add to dashboard Cite

show abstract

“…Scientific studies have to try less expensive methods, such as hot-water drilling (e . g. Iken and others, 1977), geophysical soundings (Susstrunk, 1951;Rothlisberger, 1967;Robin, 1975) observations with bore-hole cameras (Engelhardt and others, 1978), or observations in ice tunnels (Boulton, 1979). All these methods furnish information of limited accuracy or point information only.…”

Section: Introductionmentioning

confidence: 99%

Electrical Resistivity Soundings of Glacier Beds: A Test Study on Grubengletscher, Wallis, Swiss Alps

Haeberli¹,

Fisch²

1984

J. Glaciol.

View full text Add to dashboard Cite

ABSTRA CT . Elec tri cal res isti vity sounding, usin g electrodes whic h are lowered direc tl y to th e ice-rock interface in bore holes, is proposed as a technique for stud ying the exact position of glacier beds, as well as their lithologica l ch a rac teristics. A test study is d escribed on G rubeng letscher, a pa rtially cold Alpin e glacier in Switzerl a nd. Res ul ts of so undings a long a 400 m long p rofil e indicate that previo us depth determina ti o ns, based on radio echo -soundings, were in gene ral accura te to w ithin less than 50/ 0 of the ac tu al ice thic kness. The resu lts also sho w th at the glacie r rests o n nonconsolid a ted sedimen ts of considera ble thi ckness. The proposed me thod could add substa nti al inform ati o n a bo ut g lacie r sliding a nd g la cier e rosion, if a pplied al o ngsid e conve ntional d ee p drilling projec ts. I NTRODUCTI ONThe beds of existing glaciers are characterized by a wide variety of morphological and lithological conditions . These beds may be rough or smooth depending on the scale considered, and they may consist of rock or unconsolidated sediments. Sediments at glacier beds mayor may not be frozen, and they mayor may not contain ground-water. To know what conditions exist at the glacier bed in a specific case is important for several reasons.Practical applications in connection with the planning and operation of Alpine hydroelectric power stations, such as the installation of subglacial water intakes or rock galleries for water adduction, may require the exact position and the lithological characteristics of glaCier beds (e.g . Bezinge and others, 1973;Vivian and Zumstein, 1973; Wold and 0strem, 1979). From a scientific point of view, knowledge about glacier bed characteristics is essentially relevant to studies done on glacier sliding, (Ll iboutry, 1979;Weertman, 1979;Iken, 1981; Iken and others, 1983) and to those which deal with processe~ of glacier erosion (Boulton, 1979;Collins, 1979;Rothlisberger and Iken, 1981).Commercial projects mainly utilize core drillings, either from the glacier surface downwards or from already existing rock galleries upwards, to probe the glaCier bed. Scientific studies have to try less expensive methods, such as hot-water drilling (e . g. Iken and others, 1977), geophysical soundings (Susstrunk, 1951;Rothlisberger, 1967;Robin, 1975) observations with bore-hole cameras (Engelhardt and others, 1978), or observations in ice tunnels (Boulton, 1979). All these methods furnish information of limited accuracy or point information only. This paper proposes a method by which it is hoped to be able partially to fill this gap: electrical resistivity soundings of glacier beds . Elektrisc he Widerstandssondierunge n mit El e ktrod en, di e in Bohrloche rn direkt a n d e r Eisunte rg re nze in stallie rt we rde n, wcrd en fU r die U nte rsuc hung d er genau en Lage und der lithologischen Charakteristik von G letscherbetten vorgeschl agen. Eine T estmess ung am G rubengletsche r, einem teil weise ka lte n Gletsche r der Schwe...

show abstract

“…The spectacular success of ice sounding from the air in polar regions (e.g. Robin, 1974) led us to try airborne ice sounding for temperate ice. The biggest challenge was the design of adequate antennas for the low frequencies that are used in sounding temperate ice.…”

Section: The Airborne Systemmentioning

confidence: 99%

Systems for Measuring Thickness of Temperate and Polar Ice from the Ground or from the Air

Watts

Wright

1981

J. Glaciol.

View full text Add to dashboard Cite

ABSTRACT. Equipment has been designed and tested for ground-based and airborne sounding of temperate glaciers. The transmitter is a free-running pulse generator that uses avalanche-mode transistor breakdown to create high-voltage pulses. The transmit and receive antennas are resistively loaded dipoles; for the airborne system, a twin-lead transmit element and a three-layer coaxial receive element are used on the inboard end of the respective antennas. The sounders are broad band systems; oscilloscopes are used for receivers. ' The oscilloscope trace is recorded photographically in the ground-based systems. A sampling oscilloscope is used in the airborne system-the sampling process strobes the waveform to audio frequencies so that it can be recorded on magnetic tape. Echoes have been obtained from ice depths of 550 m using the airborne system and about I 000 m using the ground-based system. REsuME.

show abstract

Radio-Echo Sounding: Glaciological Interpretations and Applications

Cited by 22 publications

References 28 publications

Nature of radio echo layering in the Antarctic Ice Sheet detected by a two‐frequency experiment

Nature of radio echo layering in the Antarctic Ice Sheet detected by a two‐frequency experiment

Electrical Resistivity Soundings of Glacier Beds: A Test Study on Grubengletscher, Wallis, Swiss Alps

Systems for Measuring Thickness of Temperate and Polar Ice from the Ground or from the Air

Contact Info

Product

Resources

About