Working Groups

Addressing the two dimensions of this project will require several working groups. The research activities of the different groups will be strongly inter-linked and there will be considerable cross-over. In particular, a major area of outreach will be to the modelling community. Under IGCP 437, and its predecessor IGCP 367, the sea-level community has worked hard at developing close research links with the geophysical modelling community and this has yielded significant advances in our understanding of ice sheet history, global to regional and local sea-level change, as well as earth rheology (in particular through our close collaboration with Professor Kurt Lambeck and Professor Dick Peltier and Dr Glenn Milne). Under this proposal, we will seek to develop these links further, but also to reach out to other areas of the modelling community who are motivated by a desire to understand the dynamics of the ocean, atmosphere and cryosphere. This new level of engagement will be essential if we are to address the full range of potential driving mechanisms behind vertical changes in sea level and lateral shifts in shoreline position.

Seven working groups are proposed that will address the two project dimensions (A and B). They will be subject to discussion and ratification at the first international meeting of the project:

A. The vertical dimension of sea-level change. Correlating sea level and coastal stratigraphic data with data derived from a variety of terrestrial (including ice core) and marine depositional records.

A.1 Quaternary sea-level change and ice-sheet volume

To determine the role of meltwater flux as a driving mechanism behind changes in Quaternary sea-level. This will be achieved by building on the well-developed links between the sea-level and geophysical modelling communities established under previous IGCP projects
To correlate Quaternary sea-level records with lengthy ocean and ice core records of ice sheet volume to understand better the linkages and driving mechanisms between these depositional environments
To develop and apply high resolution techniques of palaeoenvironmental reconstruction capable of resolving detailed local and regional sea-level histories that can be correlated with other climate proxies from terrestrial and oceanic realms. To explore the link between late Holocene sea-level change and climate, and thus provide a stronger basis for appreciating the spatial patterning, driving mechanisms, leads and lags, and the impacts of future sea-level rise
To investigate the influence of precipitation and temperature on coastal evolution in polar, temperate and low latitude coastal environments

A.2 Quaternary coastal evolution and fluvial archives of environmental change

To document and understand the interactions between changes in sea level and fluvial activity over a variety of spatial and temporal scales. To determine the role of fluvial processes and sediment influx as driving mechanisms behind shoreline evolution
To compare methods and results used by the sea-level and fluvial communities in their efforts to reconstruct Late Quaternary crustal motions
To explore the implications of improved sea-level records on the dynamics of fluvial systems over short (1000 a-1), and long-term (10,000 a-1) time periods by integrating field, laboratory and modelling approaches

A.3 Quaternary sea-level and ocean circulation

To link changes in ocean circulation with patterns of sea-level change and coastal evolution. To examine the synchroneity and impact of changes in ocean circulation on the physical and ecological evolution of coasts by comparing case studies completed in different global settings
To explore the potential of paired samples of terrestrial and marine microfossils, and other proxy indicators, from coastal deposits to establish the impact of changes in ocean circulation on terrestrial and coastal environments
To isolate abrupt changes in sea-level driven by local processes, such as earthquakes, from changes due to local and regional oceanic forcing

A.4 Global to local relative sea-level change during the last 1000 years

To develop high-resolution sea-level records from the last millennia that can be directly compared with historical documentation, and observational data from more recent climate, oceanographic, and geodetic surveys. The latter will include tide-gauge, GPS and levelling data, gravity surveys, as well as glacio-isostatic adjustment geophysical models. This work will provide important baseline information against which recent and future sea-level and coastal change can be assessed
To establish maps (at a variety of scales from regional to global) depicting spatial trends in relative sea-level change during the last 1000 years as a basis for comparing with trends identified in tide gauge records from the last 100-200 years. These maps will provide essential base-line data for calibrating predictive models of regional to global sea-level change, such as those be developed by the IPPC community

B. The lateral dimension of sea-level change. The role of terrestrial and oceanic processes in driving patterns of RSL change and coastal evolution.

B.1 Sediment fingerprinting in the coastal zone

To develop further and apply existing and new field and laboratory techniques to determine terrestrial versus marine sediment sources in coastal stratigraphic sequences
Using field-based case studies, to determine the relative importance of terrestrial (especially fluvial and aeolian) controls on Quaternary coastal evolution and hence test hypotheses regarding the relative importance of these realms in controlling RSL and coastal change
To quantify Quaternary sediment flux from terrestrial and marine environments across the coastal zone in a variety of polar, temperate and low latitude coastal settings
To develop and apply methods of sediment dating to coastal deposits (building on research completed under IGCP Project 437), paying particular focus to the dating of water-lain and aeolian minerogenic sediment sequences of Quaternary age
Where possible, to develop quantitative models which capture the processes involved in sediment flux to, and across, the coastal zone

B.2 Human impact on coastal evolution and sea-level change

To establish, through local, regional and national case studies, the role of humans as drivers of Quaternary coastal change. To focus in particular on prehistoric and recent changes in catchment processes (including land-use change) and how these influence the flux of sediment, water and nutrients from land to the coast and on into the oceans
To explore the benefits of collaborative research with archaeologists in both the coastal plain and coastal catchments
To compare longer-term quantitative estimates of sediment flux and coastal change with recent (20th century) observations to determine human impact on coastal sediment flux and shoreline change. Examples include the impact of dam construction and poldering
To develop tidal amplitude and wave models capable of determining changes in tidal range and wave climate caused by human activity, specifically the activities of land claim and sea defence and bridge construction, but also changes in freshwater discharge associated with upstream activities such as deforestation and water extraction. To apply this knowledge retrospectively to better understand patterns of Quaternary and Holocene sea-level change

B.3 The role of earthquakes, tsunamis and storms as driving mechanisms of Quaternary RSL change and coastal evolution

To quantify estimates of the impacts of earthquakes, tsunamis and storms on short – and longer-term fluxes of sediment between ocean, coast and the hinterland
To develop and apply techniques of palaeoenvironmental reconstruction that can determine rapidly deposited sediment layers or landform changes arising from earthquakes, tsunamis and storms to coastal stratigraphic sequences throughout the world
To develop a protocol for identifying such events in the stratigraphic record, based on detailed case studies from a range of tectonic settings experiencing variable patterns of pre-seismic, co-seismic and inter-seismic motions