Tiltmeter Observations From Doake Ice Rumples, Ronne Ice Shelf, Antarctica (Abstract)

Content Provider	Scilit
Author	Smith, A. M.
Copyright Year	1988
Description	New tiltmeter data from Doake Ice Rumples on Ronne Ice Shelf are presented. The tiltmeters detected flexing of the ice shelf close to the grounding line, due to tidal forces. In earlier studies on Rutford Ice Stream, flow was from grounded ice into the floating ice shelf. In contrast, the area studied on Ronne Ice Shelf exhibits flow from the ice shelf on to grounded ice rumples. The data span 5 km of the up-stream ice shelf and much of the grounded ice. Approximately 30 d of continuous tilt data are available for one site on the ice shelf. Analysis of this record can determine the dominant tidal frequencies present. A number of shorter records cover periods normally of a few days. These were obtained from sites both up-stream and down-stream of the long-term site. They have been used to investigate the variation in tilt amplitude with distance from the grounding line. The approximate position of the grounding line was located from the position of strand cracks and by using surface-elevation and ice-thickness data. The tiltmeters helped to confirm this position. Over grounded ice, tidal flexing is clearly present up to about 2 km from the grounding line. Beyond this it appears to be absent. The signal recorded by tiltmeters on grounded ice farther than 2 km from the grounding line is attributed, at present, to a temperature dependency of the tiltmeters. The flexing of ice shelves at tidal frequencies has previously been treated as an elastic problem. Available models which use beam theory require the use of a time-dependent function and a reduced “effective” ice thickness in the elastic modulus. On preliminary analysis, data from the ice shelf and grounding line of Doake Ice Rumples appear to be consistent with these theories. More detailed analysis and interpretation is required in order to confirm the level of agreement and to determine possible variations due to the “reversed” nature of the flow direction.
Related Links	https://www.cambridge.org/core/services/aop-cambridge-core/content/view/8AC537B1FA3E84AB50DEA954623D4D47/S0260305500006868a.pdf/div-class-title-tiltmeter-observations-from-doake-ice-rumples-ronne-ice-shelf-antarctica-abstract-div.pdf
Ending Page	222
Page Count	1
Starting Page	222
ISSN	02603055
e-ISSN	17275644
DOI	10.1017/S0260305500006868
Journal	Annals of Glaciology
Volume Number	11
Language	English
Publisher	Cambridge University Press (CUP)
Publisher Date	1988-01-01
Access Restriction	Open
Subject Keyword	Annals of Glaciology Marine Engineering Shelf and Grounding Ice Shelf On To Grounded
Content Type	Text
Resource Type	Synopsis
Subject	Earth-Surface Processes