Abstract
High-resolution surface velocity measurements and passive seismic observations from Rutford Ice Stream, West Antarctica, 40km upstream from the grounding line are presented. These measurements indicate a complex relationship between the ocean tides and currents, basal conditions and ice-stream flow. Both the mean basal seismicity and the velocity of the ice stream are modulated by the tides. Seismic activity increases twice during each semi-diurnal tidal cycle. The tidal analysis shows the largest velocity variation is at the fortnightly period, with smaller variations superimposed at diurnal and semi-diurnal frequencies. The general pattern of the observed velocity is two velocity peaks during each semi-diurnal tidal cycle, but sometimes three peaks are observed. This pattern of two or three peaks is more regular during spring tides, when the largest-amplitude velocity variations are observed, than during neap tides. This is the first time that velocity and level of seismicity are shown to correlate and respond to tidal forcing as far as 40km upstream from the grounding line of a large ice stream.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 715-724 |
| Number of pages | 10 |
| Journal | Journal of Glaciology |
| Volume | 54 |
| Issue number | 187 |
| State | Published - 2008 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Earth-Surface Processes
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Tidal influence on Rutford Ice Stream, West Antarctica : Observations of surface flow and basal processes from closely spaced GPS and passive seismic stations. / Adalgeirsdóttir, Gua; Smith, A. M.; Murray, T.; King, M. A.; Makinson, K.; Nicholls, K. W.; Behar, A. E.
In: Journal of Glaciology, Vol. 54, No. 187, 2008, p. 715-724.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Tidal influence on Rutford Ice Stream, West Antarctica
T2 - Observations of surface flow and basal processes from closely spaced GPS and passive seismic stations
AU - Adalgeirsdóttir, Gua
AU - Smith, A. M.
AU - Murray, T.
AU - King, M. A.
AU - Makinson, K.
AU - Nicholls, K. W.
AU - Behar, A. E.
PY - 2008
Y1 - 2008
N2 - High-resolution surface velocity measurements and passive seismic observations from Rutford Ice Stream, West Antarctica, 40km upstream from the grounding line are presented. These measurements indicate a complex relationship between the ocean tides and currents, basal conditions and ice-stream flow. Both the mean basal seismicity and the velocity of the ice stream are modulated by the tides. Seismic activity increases twice during each semi-diurnal tidal cycle. The tidal analysis shows the largest velocity variation is at the fortnightly period, with smaller variations superimposed at diurnal and semi-diurnal frequencies. The general pattern of the observed velocity is two velocity peaks during each semi-diurnal tidal cycle, but sometimes three peaks are observed. This pattern of two or three peaks is more regular during spring tides, when the largest-amplitude velocity variations are observed, than during neap tides. This is the first time that velocity and level of seismicity are shown to correlate and respond to tidal forcing as far as 40km upstream from the grounding line of a large ice stream.
AB - High-resolution surface velocity measurements and passive seismic observations from Rutford Ice Stream, West Antarctica, 40km upstream from the grounding line are presented. These measurements indicate a complex relationship between the ocean tides and currents, basal conditions and ice-stream flow. Both the mean basal seismicity and the velocity of the ice stream are modulated by the tides. Seismic activity increases twice during each semi-diurnal tidal cycle. The tidal analysis shows the largest velocity variation is at the fortnightly period, with smaller variations superimposed at diurnal and semi-diurnal frequencies. The general pattern of the observed velocity is two velocity peaks during each semi-diurnal tidal cycle, but sometimes three peaks are observed. This pattern of two or three peaks is more regular during spring tides, when the largest-amplitude velocity variations are observed, than during neap tides. This is the first time that velocity and level of seismicity are shown to correlate and respond to tidal forcing as far as 40km upstream from the grounding line of a large ice stream.
UR - http://www.scopus.com/inward/record.url?scp=57049102320&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57049102320&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:57049102320
VL - 54
SP - 715
EP - 724
JO - Journal of Glaciology
JF - Journal of Glaciology
SN - 0022-1430
IS - 187
ER -