Abstract ID: 28.7342 | Accepted as Poster | Poster | 2025-02-27 13:00 - 14:30 | Ágnes‐Heller‐Haus/Small Lecture Room

The archives of over 30,000 aerial photographs from the Antarctic Peninsula (AP) acquired since 1940s are the sole direct observations available over the last century to reconstruct past glacier surface elevations. In this study, we explore the photogrammetric aerial survey by Institut für Angewandte Geodäsie (IfAG) in 1989 on southwest Antarctic Peninsula glaciers. We chose Pourquois Pas Island (PPI) as a calibration site which is situated on western Antarctic Peninsula, 50 km east of Rothera station containing varied terrain types typical of the entire Antarctic Peninsula. We tested Historical Structure from Motion (HSfM) workflow on 27 images with manually geolocated image centers from PPI. Using a multi-stage coregistration approach with Iterative Closest Point (ICP) method, we aligned the historical DSMs generated, with the reference elevation data from REMA 2m strip DEM from 2017. Despite only having rough orientation parameters available as input to the bundle adjustment, average RMS reprojection error for all models obtained was within 1 pixel. Hypsometric analysis show increasing elevation loss rates in lower elevations suggesting glacier dynamics playing key role in mass change. Future study will include further investigations on drivers of these longterm glacial changes and applying the method on other archival images from AP