The PhD defence and trial lecture will be held in Auditorium 1 in The Geology Building. In some cases, it will be possible to attend the trial lecture and dissertation digitally, in that case a link to Zoom will be posted.
Trial lecture
Tuesday 21 may, 13:15-14:00, Aud 1, The Geology Building:
Cryosphere and Earth System Science – Importance and challenges of integrative approaches
Conferral summary (in Norwegian)
Permafrost og sesongfrost kan i stor grad påvirke landskapet. I avhandlingen er det undersøkt ulike konsepter innen landskapsutvikling i kalde regioner ved hjelp av modellering av permafrost og frostforvitring, samt satellittbårne- og bakkebaserte fjernmålingsteknikker. Studien viser at permafrost både i Norge og Island er svært følsom for atmosfærisk oppvarming. Videre demonstreres det hvordan bakketemperaturen styrer frostforvitring, og at frostforvitret materiale trolig har bidratt til dannelse av spesielle landformer i Norge og Island. Avhandlingen viser også at jordsiget øker i områder med lavere bakketemperatur, og at steinsprangaktivitet øker om sommeren i fjellvegger med permafrost. Samlet sett bidrar doktorgradsarbeidet til økt forståelse av bakketemperaturens betydning for skråningsprosesser i fjellområder.
Main research findings
Popular scientific article about Czekirda’s dissertation:
Ground thermal regime and periglacial slope processes in Norway and Iceland
The occurrence of perennially (permafrost) and seasonally frozen ground substantially influences slope processes in the mountains of Norway and Iceland. Ground temperatures are increasing as part of ongoing global climate change, potentially leading to an increased number of landslides in areas underlain by thawing permafrost. Moreover, the relationships between ground temperature and slope processes such as frost weathering or slow mass movements have various implications for the evolution of landforms and landscapes. This thesis aims to gain a better understanding of these relationships.
This work uses a variety of techniques, including various GIS and remote sensing methods, modelling of permafrost and frost weathering, as well as statistical modelling. Slow movement of landforms is measured using satellite radar interferometry (InSAR). In addition, high-resolution snow mapping based on remote sensing products is conducted. Finally, erosion rates are computed using point cloud differencing and sediment volume estimation.
Permafrost modelling results revealed that relatively shallow permafrost in Iceland, as well as rock wall permafrost in Norway, are susceptible to the atmospheric warming that has been lasting since the 1980s. The thesis also presents several examples highlighting the significance of ground temperature for slope processes in mountainous regions: 1) ground temperature controls frost weathering, and frost-weathered material likely contributed to the formation of certain landforms in Norway and Iceland, 2) slow downslope movement of soil mainly occurs in sparsely vegetated areas with lower ground temperatures, 3) rockfall activity increases in permafrost rock walls during the summer.
Photo and other information:
Other photo material: Photo with description and credit as specified in the article above, size 2000px.
