Dr Sasha Montelli will deliver the ESE Departmental Seminar on Thursday the 1st of February 2024: “Past ice-ocean-bedrock interactions: geomorphological and numerical reconstructions from the Barents Sea and West Antarctica”.
Join us in room G41 – RSM Building – on Thursday 1st of February 2024 at 12h15.
Abstract
High-latitude regions contain important palaeoclimatic archives that can be used to reconstruct the interplay between ice sheets, the oceans surrounding them, and the bedrock beneath. This talk presents two case studies, offering reconstructions from marine and glacial domains. In the first example, we combine new observations from the Barents Sea with ice-sheet-hydrate modeling to show that during the Late Weichselian, ice decay led to the rapid destabilisation and full drainage of shallow hydrate reservoirs, along with permafrost thaw. This process caused glaciotectonism and craterisation, likely accompanied by large fluxes of carbon released into the water column. The second example demonstrates how englacial borehole temperature modelling and measurements from the Antarctic Ice Sheet can be used to infer the timing of past ice-shelf grounding. Sensitivity tests reveal that the past ocean temperature history and geothermal heat flux represent the dominant sources of uncertainty in dating ice rises, as well as the disintegration history of subglacial carbon pools.
About the speaker
Sasha is a geophysicist and glaciologist. His research combines marine geophysical data with sediment cores and numerical modelling to reconstruct past interactions between ice sheets, ocean and solid earth. He received his BSc and MSci from Saint Petersburg State University, Russia, and his PhD from the University of Cambridge, where he worked at the Scott Polar Research Institute. Before starting his current position as Lecturer in Environmental Change at UCL, Sasha was a Schmidt Science Fellow at Columbia University, and a Junior Research Fellow at Peterhouse, University of Cambridge.
Sasha’s current research interests encompass ice-sheet evolution and interactions between ice, ocean, atmosphere and solid earth on multiple temporal and spatial scales.
He uses interdisciplinary field- and laboratory-based approaches including the acquisition, processing and interpretation of high-resolution bathymetric, 2D and 3D seismic data; analysis of deep-drilling and sediment cores; and implementation of large-scale and targeted ice-sheet simulations.
The geography of Sasha’s projects span both hemispheres, including East and West Antarctica, the Eurasian Arctic and the subarctic Pacific.