GSNZ Wellington branch event
School of Geography, Environment and Earth Sciences PhD Seminar Series - All Welcome
The subglacial landscape and hydrology of Antarctica mapped from space
Speaker: Wei Ji Leong
To narrow uncertainties in the Antarctic ice sheet's contribution to sea level rise, we present a collection of novel machine learning and automated satellite remote sensing methods which use ice surface observations to infer the subglacial nature of Antarctica.
A superresolution deep neural network called DeepBedMap was designed and trained to produce a high-resolution (250m) bed elevation model of Antarctica called DeepBedMap_DEM that preserves bed roughness details useful for catchment-to-continent-scale ice sheet modelling. This DeepBedMap_DEM is compared with a smoother, medium-resolution (500m) BedMachine topography in a basal inversion experiment over Pine Island Glacier, with results motivating more research into the interacting roles of subglacial hydrology which influences skin drag and high resolution bed topographies which influences form drag. Active subglacial lakes in Antarctica were mapped using an unsupervised density-based classification method on ICESat-2 point cloud data from 2018-2020, yielding 195 active subglacial lakes, including 36 new lakes in the 86-88°S area not detected by the previous ICESat (2003-2009) mission.
This thesis showcases both the rich diversity in subglacial landscapes and the dynamic nature of subglacial hydrology in Antarctica, forming a foundation enabling the accurate modelling of overland ice flow in critical regions of the vulnerable West Antarctic Ice Sheet.
This event will be available live via zoom.