Climate change and warming have been linked to enhanced coastal erosion in the arctic. Specifically, permafrost is believed to be thawing at greater rates, and wave dynamics are expected to increase in intensity. As a result, thermokarst activity, which includes the occurrence of retrogressive thaw slumps, will be more frequent along arctic coasts. / The availability of airborne and spaceborne imagery in the arctic over the last fifty years has made possible the temporal analysis of permafrost and ground ice-related erosion. The objectives of this thesis are (1) the creation of a large scale database for horizontal coastal retreat on Herschel Island for the 1952-2000 timespan, (2) the investigation of retrogressive thaw slump activity over the same period and its relation to coastal erosion, and (3) the elaboration of stereophotogrammetric techniques to investigate retrogressive thaw slump activity volumetrically. Herschel Island, located on the northern coast of the Yukon Territory, was chosen as the study site for this research, because of the widespread presence of retrogressive thaw slumps and the lack of data for coastal erosion during the last fifty years. / Photogrammetric tools were used to create orthorectified and stereo-images of the Island for the years 1952, 1970, 2000 and 2004 from airphoto archives and Ikonos (1 m resolution) imagery. Coastal erosion was found to be stable or declining on Herschel Island except in the vicinity of retrogressive thaw slumps. In addition, retrogressive thaw slumps were identified on the imagery and observed to have increased in frequency for the 1952-2000 period. / Stereophotogrammetric analysis of two retrogressive thaw slumps showed that eroded sediment volumes from these landforms are considerable and should be included in future assessments of sediment release from arctic coasts to the oceanic shelves.

The Orcadian coastline is characterised by a high energy paraglacial environment, where remobilisation of abundant glacigenic sediment has favoured the building of numerous barriers. To date, there has been little work on either patterns of relative sea-level change or coastal processes affecting Orkney during the Flandrian. The present research provides an understanding of Flandrian coastal environmental changes in three areas of Mainland Orkney. Detailed morphological, lithostratigraphical and biostratigraphical work was undertaken and has revealed distinctive back-barrier sequences which illustrate the diversity of coastal responses to complex interactions between relative sea-level trends, sediment supply and coastal configuration. Scapa Bay provides direct evidence of relative sea-level rise and coastal retreat during the early Flandrian. There, a freshwater marsh was flooded by the sea c.8.5 kyrs BP at c.-5.4 m 0.0. Abundant sediment supply from nearby drift cliffs was remobilised inland by wave refraction before c.7 kyrs BP, and led to the formation and rapid progradation of swash-aligned barriers (SAB) across the valley mouth. By c.6.6 kyrs BP, direct marine influence was restricted in the back-barrier area, although saltmarshes persisted until c.5 kyrs BP. The enclosed lagoon was then progressively infilled by terrestrial sediments and a freshwater marsh was formed. The multiple barrier complex at Scapa Bay demonstrates land progradation against the backdrop of long-term rising relative sea level. This was facilitated by continuous sediment supply in a sheltered embayment. At the Bay of Carness, a single SAB was built during the early Flandrian. Between c.6.5 and 5.4 kyrs BP, marine influence was at its highest and a saltmarsh formed between c.-3.2 and -2.57 m 0.0. No direct marine flooding has, however, been recorded at the site. Later, a brackish lagoon occupied the coastal depression indicating a rising water table. This lagoon was gradually infilled by terrestrial sediments as soil erosion occurred in the the catchment. Slow inland migration of the SAB during the late Flandrian has been related to complex barrier and lagoon interactions in a context of sediment starvation. The sheltered setting of the site enabled the barrier to keep cohesiveness throughout its inland translocation. However, its present morphology shows clear signs of instability. The Bay of Skaill is the most exposed and dynamic coastal environment of the sites investigated. Abundant sand supply led to the building of a dune ridge during the middle Flandrian and to the pending of a freshwater loch in the back-dune area. By c.6.1 kyrs BP, aeolian processes became dominant and the dune ridge progressively migrated landward, while machair developed inland. After c.4.4 kyrs BP, the bay was gradually formed as the dune ridge retreated to its present position. Moreover, a SAB developed and eroded the seaward dune edge. At present, the SAB is migrating rapidly inland due to sediment starvation and exposure to storm activity. The Flandrian vegetational history around the three sites was also investigated. This accorded with that already established for the islands. Herbaceous vegetation was initially dominant, although a Betula-Corylus woodland, including Salix, Alnus and possibly Quercus, developed during the early Flandrian. This reached its maximum extent c.5 kyrs BP. Anthropogenic impact from Neolithic onwards is believed to have significantly affected the landscape studied, primarily via woodland clearance and mixed farming practices. Between c.4 and 2.5 kyrs BP, a combination of natural and anthropogenic factors led to the spreading of heathland and to a possible decline of anthropogenic activities.

Thesis (Ph. D.)--Utrecht University, 2007. / Afterword and vita in both English and Dutch. Includes bibliographical references (p. 115-120).

Thesis (M.Sc. Earth and Ocean Sciences)--University of Waikato, 2008. / Title from PDF cover (viewed September 18, 2008) Includes bibliographical references (p. 121-123)

Thesis (Ph. D.)--University of California, Santa Cruz, 1995. / Typescript. Includes bibliographical references.

Thesis (Ph. D.)--Uppsala University, 1990. / One map on folded sheet in pocket. Includes bibliographical references (p. 134-136).

Thesis (Ph. D.)--Australian National University, 1980. / Includes bibliographical references (leaves 343-357).

Thesis (Ph. D.)--Oregon State University, 2006. / Printout. Includes bibliographical references. Also available online.

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