An investigation of the possibility of non-Laurentide ice stream contributions to Heinrich event 3

2020 ◽  
pp. 1-13
Author(s):  
Jesse Velay-Vitow ◽  
W. Richard Peltier ◽  
Gordan R. Stuhne
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Barents Sea ◽  
High Amplitude ◽  
Irish Sea ◽  
Ice Streams ◽  
Atlantic Sector ◽  
Heinrich Event ◽  
Ice Stream ◽  
The Irish Sea

Abstract The ocean floor sedimentological signature of Heinrich event 3 (H3) is markedly different from that of other Heinrich events that are known to have originated in Hudson Strait. It has therefore been suggested that the H3 contribution to iceberg flux may have been delivered by ice streams located in the eastern sector of the North Atlantic, from the Fennoscandian or British Isles ice sheets. To investigate this possibility and whether the instability involved may have been tidally induced, as seems to have been the case for H1, we consider several eastern Atlantic sector possibilities: a hypothetical Barents Sea ice stream, the Norwegian ice stream, and the Irish Sea ice stream. We find that the extremely high amplitude of the M2 tidal constituent in the western North Atlantic that appears to have forced H1 did not exist in the northeastern Atlantic. This suggests that, with one possible exception, if destabilized ice streams in this region did contribute to H3, tidal forcing was most probably not the cause. The single exception to this general conclusion may be the Irish Sea ice stream, and we comment on the probability of a contribution to H3 from this source.

scholarly journals Rapid marine deglaciation: asynchronous retreat dynamics between the Irish Sea Ice Stream and terrestrial outlet glaciers

2013 ◽  
Vol 1 (1) ◽  
pp. 277-309
Author(s):  
H. Patton ◽  
A. Hubbard ◽  
T. Bradwell ◽  
N. F. Glasser ◽  
M. J. Hambrey ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Irish Sea ◽  
Swath Bathymetry ◽  
Ice Stream ◽  
Non Linear ◽  
Polar Ice Sheets ◽  
The Irish Sea ◽  
Short Time

Abstract. Understanding the retreat behaviour of past marine-ice sheets provides vital context to accurate assessment of the present stability and long-term response of contemporary polar-ice sheets to climate and oceanic warming. Here new multibeam swath-bathymetry data and sedimentological analysis are combined with high resolution ice-sheet modelling to reveal complex landform assemblages and process-dynamics associated with deglaciation of the British-Celtic Ice Sheet (BCIS) within the Irish Sea Basin. Our reconstruction indicates a non-linear relationship between the rapidly receding Irish Sea Ice Stream, the largest draining the BCIS, and the retreat of outlet glaciers draining the adjacent, terrestrially based ice sheet centred over Wales. Retreat of Welsh ice was episodic; superimposed over low-order oscillations of its margin are asynchronous outlet re-advances driven by catchment-wide mass balance variations that are amplified through migration of the ice cap's main ice-divide. Formation of large, linear ridges which extend at least 12.5 km offshore (locally known as sarns) and dominate the regional bathymetry are attributed to repeated frontal and medial morainic deposition associated with the re-advancing phases of these outlet glaciers. Our study provides new insight into ice-sheet extent, dynamics and non-linear retreat across a major palaeo-ice stream confluence zone, and has ramifications for the interpretation of recent fluctuations observed by satellites over short-time scales across marine-sectors of the Greenland and Antarctic ice sheets.

Bayesian modelling the retreat of the Irish Sea Ice Stream

2013 ◽  
Vol 28 (2) ◽  
pp. 200-209 ◽  
Author(s):  
Richard C. Chiverrell ◽  
Ian M. Thrasher ◽  
Geoffrey S. P. Thomas ◽  
Andreas Lang ◽  
James D. Scourse ◽  
...  
Keyword(s):  
Sea Ice ◽  
Irish Sea ◽  
Bayesian Modelling ◽  
Ice Stream ◽  
The Irish Sea

scholarly journals Rapid marine deglaciation: asynchronous retreat dynamics between the Irish Sea Ice Stream and terrestrial outlet glaciers

2013 ◽  
Vol 1 (1) ◽  
pp. 53-65 ◽  
Author(s):  
H. Patton ◽  
A. Hubbard ◽  
T. Bradwell ◽  
N. F. Glasser ◽  
M. J. Hambrey ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Irish Sea ◽  
Swath Bathymetry ◽  
Ice Cap ◽  
Ice Stream ◽  
Non Linear ◽  
Polar Ice Sheets ◽  
The Irish Sea

Abstract. Understanding the retreat behaviour of past marine-based ice sheets provides vital context for accurate assessments of the present stability and long-term response of contemporary polar ice sheets to climate and oceanic warming. Here new multibeam swath bathymetry data and sedimentological analysis are combined with high resolution ice-sheet modelling to reveal complex landform assemblages and process dynamics associated with deglaciation of the Celtic ice sheet within the Irish Sea Basin. Our reconstruction indicates a non-linear relationship between the rapidly receding Irish Sea Ice Stream and the retreat of outlet glaciers draining the adjacent, terrestrially based ice cap centred over Wales. Retreat of Welsh ice was episodic; superimposed over low-order oscillations of its margin are asynchronous outlet readvances driven by catchment-wide mass balance variations that are amplified through migration of the ice cap's main ice divide. Formation of large, linear ridges which extend at least 12.5 km offshore (locally known as sarns) and which dominate the regional bathymetry are attributed to repeated frontal and medial morainic deposition associated with the readvancing phases of these outlet glaciers. Our study provides new insight into ice-sheet extent, dynamics and non-linear retreat across a major palaeo-ice stream confluence zone, and has ramifications for the interpretation of recent fluctuations observed by satellites over short timescales across marine sectors of the Greenland and Antarctic ice sheets.

scholarly journals Bed erosion during fast ice streaming regulated the retreat dynamics of the Irish Sea Ice Stream

2020 ◽  
Vol 245 ◽  
pp. 106526 ◽  
Author(s):  
Katrien J.J. Van Landeghem ◽  
Richard C. Chiverrell
Keyword(s):  
Sea Ice ◽  
Irish Sea ◽  
Ice Stream ◽  
Bed Erosion ◽  
Fast Ice ◽  
The Irish Sea

scholarly journals Advance and retreat of the marine-terminating Irish Sea Ice Stream into the Celtic Sea during the Last Glacial: Timing and maximum extent

2019 ◽  
Vol 412 ◽  
pp. 53-68 ◽  
Author(s):  
James Scourse ◽  
Margot Saher ◽  
Katrien J.J. Van Landeghem ◽  
Edward Lockhart ◽  
Catriona Purcell ◽  
...  
Keyword(s):  
Sea Ice ◽  
Irish Sea ◽  
Maximum Extent ◽  
Last Glacial ◽  
Ice Stream ◽  
Celtic Sea ◽  
The Last Glacial

scholarly journals The link between the Barents Sea and ENSO events simulated by NEMO model

Ocean Science ◽  
2012 ◽  
Vol 8 (6) ◽  
pp. 971-982 ◽  
Author(s):  
V. N. Stepanov ◽  
H. Zuo ◽  
K. Haines
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Barents Sea ◽  
Southern Oscillation ◽  
Similar Response ◽  
Enso Events ◽  
Ice Volume ◽  
The North ◽  
The Barents Sea ◽  
The North Atlantic

Abstract. An analysis of observational data in the Barents Sea along a meridian at 33°30' E between 70°30' and 72°30' N has reported a negative correlation between El Niño/La Niña Southern Oscillation (ENSO) events and water temperature in the top 200 m: the temperature drops about 0.5 °C during warm ENSO events while during cold ENSO events the top 200 m layer of the Barents Sea is warmer. Results from 1 and 1/4-degree global NEMO models show a similar response for the whole Barents Sea. During the strong warm ENSO event in 1997–1998 an anomalous anticyclonic atmospheric circulation over the Barents Sea enhances heat loses, as well as substantially influencing the Barents Sea inflow from the North Atlantic, via changes in ocean currents. Under normal conditions along the Scandinavian peninsula there is a warm current entering the Barents Sea from the North Atlantic, however after the 1997–1998 event this current is weakened. During 1997–1998 the model annual mean temperature in the Barents Sea is decreased by about 0.8 °C, also resulting in a higher sea ice volume. In contrast during the cold ENSO events in 1999–2000 and 2007–2008, the model shows a lower sea ice volume, and higher annual mean temperatures in the upper layer of the Barents Sea of about 0.7 °C. An analysis of model data shows that the strength of the Atlantic inflow in the Barents Sea is the main cause of heat content variability, and is forced by changing pressure and winds in the North Atlantic. However, surface heat-exchange with the atmosphere provides the means by which the Barents sea heat budget relaxes to normal in the subsequent year after the ENSO events.

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