GPS determination of the velocity and strain-rate fields on Schirmacher Glacier, central Dronning Maud Land, Antarctica

Sunil, P. S.; Reddy, C. D.; Ponraj, Mohanadoss; Dhar, Ajay; Jayapaul, D.

doi:10.3189/002214307784409199

Cited by 23 publications

(14 citation statements)

References 27 publications

(36 reference statements)

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“…Global positioning system (GPS) campaigns were conducted during summer seasons to obtain insight into the velocity and strain-rate distribution on Schirmacher Glacier, central Dronning Maud Land, East Antarctica. GPS data were collected at 21 sites and analysed to estimate the site coordinates, baselines and velocities (Sunil et al, 2007). The velocity and strain-rate distributions across the GPS network in Schirmacher Glacier were spatially correlated with topography, subsurface undulations, fracture zones/crevasses and the partial blockage of the flow by Nunataks and the Schirmacher Oasis (Fig.…”

Section: High-resolution Satellite Data Applicationsmentioning

confidence: 99%

Polar Ice Sheet and Glacier Studies-Indian Efforts in last Five Years

Thakur

2017

Proceedings of the Indian National Science Academy

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Indian scientists have been involved in studies of cryosphere in Polar Regions from past 35 years. For continuous monitoring and expanding research in the fields of atmospheric science, geosciences, glaciology, environmental sciences, etc. specific to these regions, the ESSO -National Centre for Antarctic and Ocean Research (ESSO-NCAOR) has established three permanent research stations in Antarctica. This paper addresses efforts by Indian scientists in last five years in cryospheric studies on the Antarctica using remote sensing data. Inventories of Antarctic glaciers and ice sheet features prepared by Indian researchers have facilitated for detailed long-term studies on glacier dynamics, sea ice, fluctuations of the continental ice margin and snouts of glaciers. For safe and optimal navigation of ships, a sea ice advisory has been also set up. This paper also addresses recent efforts of using high-resolution earth observation satellite data which were acquired for geospatial mapping of cryospheric features and glacial landforms and for delineation of wind induced snow deposition zones in part of the Antarctica. Spatiotemporal dynamics of surface melting over Antarctic was further studied by using moderate resolution satellite data.

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Section: High-resolution Satellite Data Applicationsmentioning

confidence: 99%

Polar Ice Sheet and Glacier Studies-Indian Efforts in last Five Years

Thakur

2017

Proceedings of the Indian National Science Academy

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“…The principal strain rates provide a quantitative measurement of extension rates, which range from (0.04±0.02) x 10 -3 to (0.96±0.16) x 10 -3 a -1 . The velocity and strain rate distributions across the GPS network in Schirmacher Glacier were spatially correlated with topography, subsurface undulations, fracture zones/ crevasses and the partial blockage of the flow by nunataks and the Schirmacher Oasis (Sunil et al, 2007).…”

Section: Gps Measurements For Crustal Deformation Mass Balance and Imentioning

confidence: 99%

“…A magnetic survey of Bharati promontory was carried out to compile a magnetic anomaly map of the area (Reddy and Dhar, 2007). It is observed that the high magnetic field anomaly regions are concentrated over some pockets which are located on high ridges.…”

Section: Magnetic Anomaly Map Of Bharati Promontorymentioning

confidence: 99%

India's Contribution to Geomagnetism and Allied Studies in Antarctica-A Review

Sinha

2017

Proceedings of the Indian National Science Academy

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In this paper, we review the progress in Geomagnetism and allied areas based on the past thirty five Indian Antarctic expeditions and summarize the scientific results obtained in the last decade. Various dynamic processes in the near-Earth space environment, driven by the transient changes in geomagnetic field such as storms and substorms, severely affect the space weather over the Polar Regions. Magnetopsheric substorms lead to the intensification of ionospheric currents and auroral outbursts within the auroral oval, causing energetic charged particles in the auroral region to come down to D-region ionosphere, which is reflected as Cosmic Noise Absorption (CNA) as monitored by imaging RIOmeter at Indian Antarctic station, Maitri (Geog. 70.75 o S, 11.73 o E; Geom. 66.84 o S, 56.29 o E). A systematic rapid decline in The Earth's complex main magnetic field at Maitri (~110 nT/yr) is important for monitoring the evolution of reverse magnetic flux patches due to physical processes occurring in the outer core of the Earth. The Global Electric Circuit (GEC) studies were started to understand the solar-terrestrial relationship and associated changes in surface weather and the near-earth electrical environment. Schumann resonances (SRs), the AC part of GEC reveal a strong UT variation of amplitude in seasonal as well as yearly time scales. The observed diurnal variation is explained in terms of the dominant thunderstorm activity centered over the three convectively active regions, viz. Asia/Maritime Continent (Indonesia), South America and Africa.The velocity and strain distribution of Schirmarchaer Glacier was investigated during two GPS campaigns in the year 2003 and 2004. The studies indicate that the horizontal velocity is in the range of 1.89-10.88 ma -1 with an average velocity of 6.21 ma -1 .

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“…The principal strain rates provide a quantitative measurement of extension rates, which range from (0.11±0.01) & times 10-3 to (1.48±0.85) × 10-3 a-1, and shortening rates, which range from (0.04±0.02) × 10-3 to (0.96±0.16) × 10-3 a-1. The velocity and strain-rate distributions across the GPS network in the ice sheet, south of Schirmacher Oasis are spatially correlated with topography, subsurface undulations, fracture zones/crevasses and the partial blockage of the flow by nunataks and the Schirmacher Oasis (Sunil et al, 2007(Sunil et al, , 2010.…”

Section: Ice Sheet Dynamicsmentioning

confidence: 99%

“…The calculation of the shifting of stakes located on the Polar ice sheet with the help of hand-held GPS shows that the Polar ice sheet is moving very slowly by 2.5 m per year towards N33E, as observed in the period between 2010-11 and 2014-2015(Swain and Raghuram, 2015.…”

Section: Snow Accumulation/aablation On Ice Sheetmentioning

confidence: 99%

Antarctic Glacier Monitoring

Shrivastava

2017

Proceedings of the Indian National Science Academy

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Polar ice is an important component of the natural system, affecting global climate on large as well as small scale. The Antarctic ice sheet has undergone significant changes in the past and governed the earth's climatic system. This ice sheet appears to have been very dynamic and yet, not much is known about the processes involved for this dynamism.Glaciological studies in parts of Central Donning Maud Land (cDML) of East Antarctica include monitoring the changes of Antarctic ice sheet overriding the Schirmacher Oasis, measurement of snow accumulation on the ice sheet, study of subsurface topography and ice sheet dynamics. In the last three decades, Dakshin Gangotri (DG) glacier snout, which is a part of East Antarctic Ice sheet (EAIS) overriding Schirmacher Oasis shows continuous recession. There are major peaks of recession in every five year cycle. The higher average annual surface air temperature leads to the greater recession in the next year. Interestingly, this recessional trend of DG snout does not show perfect correlation with the meteorological parameters (such as surface air temperature, ground temperature, wind speed, etc.) of this area. This all reflect towards the existence of very complex equation for the recession of ice sheet and snow and ice characterization in this part of Antarctica. The vector component of ice sheet shows differential movement all along the southern edge of Schirmacher Oasis. The average annual recession of snout has shown positive correlation with the mean annual runoff and negative correlation with annual mass balance of the area.

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GPS determination of the velocity and strain-rate fields on Schirmacher Glacier, central Dronning Maud Land, Antarctica

Cited by 23 publications

References 27 publications

Polar Ice Sheet and Glacier Studies-Indian Efforts in last Five Years

Polar Ice Sheet and Glacier Studies-Indian Efforts in last Five Years

India's Contribution to Geomagnetism and Allied Studies in Antarctica-A Review

Antarctic Glacier Monitoring

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