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Sea-Level Rise Due to Climate Change
Published in Saeid Eslamian, Faezeh Eslamian, Flood Handbook, 2022
There is an absence of a thorough understanding of the processes that control ice sheet behavior and limited observations on how glaciers and ice sheets respond to climate change. Paleo-climatic data showed that the warming during 1951–2000 was unusual in the past 1,300 years. The last time the Polar Regions were significantly warmer than the present for an extended period of about 125,000 years ago. Otto-Bliesner et al. (2006) used a global climate model, a dynamic ice sheet model, and paleo-climatic data to evaluate the warming in the Northern Hemisphere and its impact on the Arctic ice fields during the Last Interglaciation (LIG), ~116,000–130,000 years ago. Their simulated climate matches paleo-climatic observations of past warming, and the combination of physically based climate and ice-sheet modeling with ice-core constraints indicated that the GIS and other circum-Arctic ice fields contributed 2.2 to 3.4 meters of SLR during the LIG. Overpeck et al. (2006) using a similar method concluded that under a present scenario, similar areas of Greenland could melt causing an SLR of several meters by 2100.
Recent Advances in Seismo-Geophysical Studies for the Arctic Region under Climate Change Scenario
Published in Neloy Khare, Climate Change in the Arctic, 2022
O. P. Mishra, Priya Singh, Neloy Khare
On the basis of the numerical modelling of a realistic ice sheet model, it was inferred that the near-surface seismic source produced a very characteristic wave train with a group velocity smaller than the S-wave speed in the ice treated as an ice sheet guided. S-wave developed by the superposition of post-critical reflections between the free surface and the ice bed, is referred to as Le, analogous to Lg wave, a crustally guided wave (Toyokuni et al. 2015). The analyses showed that the crustal Sg-coda wave has variability from 3.1 to 2.6 km/s and that corresponds to the characteristics waveform observed from the Greenland ice sheet.
Dynamics of a retreating ice sheet: a LiDAR study in Värmland, SW Sweden
Published in GFF, 2020
Alastair Goodship, Helena Alexanderson
The dynamics of ice margins over millennial to centennial scales are reasonably well established but the decadal to annual pattern of ice movement is less well understood. Monitoring of present day ice sheets shows annual variation in seasonal advance and retreat more rapid than previously thought possible (Truffer & Fahnestock 2007). There is a need to understand ice sheet margin dynamics on human scales from annual up to centennial due to the influence the retreating Greenland and Antarctic ice sheets will have on sea levels and climate in the immediate future. Ice-sheet modelling is a key tool to analyse dynamics on this scale, but this relies on input of reliable data both from present day observations across Greenland and Antarctica and from patterns of ice sheet retreat determined from the geological record. Thus, linking of current ice-sheet dynamics and annual to decadal observations to the larger scale pattern of retreat during the termination of the last glaciation is a key area of research. Attaining a more detailed model of retreat of former ice-sheets will allow better calibration of ice-sheet models focussed on Greenland and Antarctica.
Melting ice and rising seas – connecting projected change in Antarctica’s ice sheets to communities in Aotearoa New Zealand
Published in Journal of the Royal Society of New Zealand, 2023
Richard Levy, Timothy Naish, Daniel Lowry, Rebecca Priestley, Rachelle Winefield, Alanna Alevropolous-Borrill, Emory Beck, Rob Bell, Graeme Blick, Ruzica Dadic, Tasman Gillies, Nicholas Golledge, Zoe Heine, Stefan Jendersie, Judy Lawrence, Katherine O’Leary, Ryan Paulik, Ceridwyn Roberts, Mike Taitoko, Natalie Trayling
First, there remains a critical need to enhance our understanding of the physical processes that drive ice sheet retreat (and advance) to improve our climate and ice sheet models and Antarctic Ice Sheet projections (Colleoni et al. 2022). In this paper, we summarise the current state of numerical climate and ice sheet modelling and future projections. We analyse results from Ice Sheet Model Intercomparison Project 6 (ISMIP6) and highlight new work to couple ice sheet and ocean models, which represents a step forward in our ability to project the future response of Antarctica’s ice shelves and consequences for grounded ice.