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Author Topic: Hazard Analysis for the FRIS/RIS in the 2012 to 2060 Timeframe  (Read 27175 times)

AbruptSLR

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Re: Hazard Analysis for the FRIS/RIS in the 2012 to 2060 Timeframe
« Reply #50 on: February 17, 2018, 07:16:33 PM »
The linked article cites new research indicating that the underside of the RIS is thermally insulated by cold fresh meltwater on its underside.  This raises the question of what would happen to the RIS in the future if climate change causes ocean currents to flow under the RIS and displace this meltwater.

Kornei, K. (2018), Fresh insights into what protects Antarctica’s Ross Ice Shelf, Eos, 99, https://doi.org/10.1029/2018EO093057.

https://eos.org/articles/fresh-insights-into-what-protects-antarcticas-ross-ice-shelf?utm_source=eos&utm_medium=email&utm_campaign=EosBuzz021618

Extract: "The team found that a layer of fresh, cold water that melts off the bottom of the ice shelf acts like insulation, protecting the underside of the shelf from melting further."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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AbruptSLR

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Re: Hazard Analysis for the FRIS/RIS in the 2012 to 2060 Timeframe
« Reply #51 on: March 14, 2018, 05:12:00 PM »
The linked reference indicates that the RIS will slowly continue to thin with or without ocean warming:

Adam J. Campbell, Christina L. Hulbe & Choon-Ki Lee (11 January 2018), "Ice Stream Slowdown Will Drive Long-Term Thinning of the Ross Ice Shelf, With or Without Ocean Warming", Geophysical Research Letters, DOI: 10.1002/2017GL075794

http://onlinelibrary.wiley.com/doi/10.1002/2017GL075794/full

Abstract: "As time series observations of Antarctic change proliferate, it is imperative that mathematical frameworks through which they are understood keep pace. Here we present a new method of interpreting remotely sensed change using spatial statistics and apply it to the specific case of thickness change on the Ross Ice Shelf. First, a numerical model of ice shelf flow is used together with empirical orthogonal function analysis to generate characteristic patterns of response to specific forcings. Because they are continuous and scalable in space and time, the patterns allow short duration observations to be placed in a longer time series context. Second, focusing only on changes that are statistically significant, the synthetic response surfaces are used to extract magnitude and timing of past events from the observational data. Slowdown of Kamb and Whillans Ice Streams is clearly detectable in remotely sensed thickness change. Moreover, those past events will continue to drive thinning into the future."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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AbruptSLR

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Re: Hazard Analysis for the FRIS/RIS in the 2012 to 2060 Timeframe
« Reply #52 on: July 26, 2018, 07:17:45 PM »
Seawater percolation into below sea level layers of the firn in Antarctic ice shelves is not a good thing, and is more widespread than previously assumed:

Cook, S., Galton-Fenzi, B. K., Ligtenberg, S. R. M., and Coleman, R.: Brief Communication: Widespread potential for seawater infiltration on Antarctic ice shelves, The Cryosphere Discuss., https://doi.org/10.5194/tc-2018-146, in review, 2018.

https://www.the-cryosphere-discuss.net/tc-2018-146/

Abstract. Antarctica's future contribution to sea level change depends on the fate of its fringing ice shelves. One variable which may affect the rates of iceberg calving from ice shelves is the presence of liquid water, including the percolation of seawater into permeable firn layers. Here, we present evidence that most ice shelves around Antarctica have regions where permeable firn exists below sea level. The findings indicate that seawater infiltration onto ice shelves may be much more widespread in Antarctica than previously recognised. Our results present the most likely locations for seawater infiltration to occur, and may be used as an indicator of where future radar studies might be focussed.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

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Re: Hazard Analysis for the FRIS/RIS in the 2012 to 2060 Timeframe
« Reply #53 on: October 17, 2018, 07:04:38 PM »
For those who are interested, the linked reference discusses a means to use seismological monitoring to continually monitor the near-surface conditions of the Ross and other ice shelves.

Chaput, J., Aster, R. C., McGrath, D., Baker,M.,Anthony,R.E.,Gerstoft,P., et al. (2018). Near-surface environmentally forced changes in the Ross Ice Shelf observed with ambient seismic noise. Geophysical Research Letters, 45. https://doi.org/10.1029/2018GL079665

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2018GL079665

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson