Thirty years on from the first IGCP coastal project, the global sea-level community is now well-equipped to develop local, regional and global records of relative sea-level (RSL) change. It is also increasingly able to describe linkages between terrestrial, coastal and marine environments through the application of new techniques of sediment finger-printing, dating, as well as quantitative models of coastal change, sea-level change and sediment flux.
However, we have so far been less successful in determining the driving mechanisms of the patterns we observe and reconstruct. This contrasts with many other areas of Quaternary science where, motivated by the emerging climate records from ice sheets and oceans, research scientists are eagerly pursuing the driving mechanisms of climate change or ocean circulation through hypothesis testing and model building.
In this project, we aim to redress this gap by refocusing the efforts of the coastal research community on establishing the driving mechanisms behind Quaternary sea-level change and coastal evolution. Our focus is primarily on the coastal zone, where a rich sediment and landform archive provides a superb opportunity for studying interactions and determining driving mechanisms over a range of spatial (global to local) and temporal (millennia to years) scales. The work will result in fundamental new knowledge regarding the driving mechanisms that influence land-ocean interactions of wide interest to the Quaternary, earth science, and marine scientists. Its strong applied component will be directly relevant to coastal managers concerned with coastal forecasting and future sea-level change.
The work will have two dimensions: the vertical dimension of RSL change and the lateral dimension of changing shoreline position. These changes in the coastal zone result from external forces (such as sea-level and climate change) and internal forces (including the coastal sedimentary budget), both of which we will address through hypothesis testing and model building.
Under the first dimension, IGCP495 will develop high-resolution (centimeter to meter scale vertical resolution and annual to centennial scale age resolution) records of vertical changes in RSL that can be meaningfully compared with other local, regional and global environmental records derived from terrestrial and marine environments. The project will develop new quantitative models of RSL change based on a range of fossil indicators, as well as a more standardised approach to data collection and analysis to facilitate international correlation. A key objective here will be to test hypotheses regarding the driving mechanisms behind vertical changes in sea-level over different spatial and temporal scales, including the influences of ocean circulation, climate change and neotectonics.
The second dimension will use a combination of geological and archaeological data to better understand the interaction of terrestrial and marine processes in controlling lateral changes in shoreline position. This will require close co-operation with workers in related disciplines, including those focused on fluvial and nearshore environments. It will, importantly, require collaboration with archaeologists interested in documenting and understanding the history of human impact on the coastal zone. This latter synergy will open the project to a new discipline area, something that hitherto has been rather overlooked by previous IGCP coastal projects. In particular, it will provide important new insights into the timing, controls and magnitudes of sediment flux to the coast, and the longer-term impacts of human action on coastal and nearshore environments. It will also yield new information regarding the magnitude and timing of RSL change (which can often be accurately reconstructed using archaeological data).
The project seeks to promote international co-operation in research concerned with land-ocean interactions and the driving mechanisms behind RSL change and coastal evolution. It is strongly interdisciplinary and will involve collaboration between physical geographers, geologists, archaeologists and geophysicists, as well as researchers in marine sciences, fluvial hydrology and atmospheric sciences. As such, it is central to the aims of the IGCP in several ways:
- It seeks to promote an increase in knowledge of geological processes and concepts through correlating studies completed at a wide range of sites throughout the world
- It will improve the standards of research methods and techniques used in examining RSL and coastal evolution over a range of temporal and spatial scales. An important element of the project will be the development of a manual for the collection and analysis of sea-level data and coastal evolution, as well as the development and dissemination of best practice through training workshops associated with the annual field meetings
- It will enhance our understanding of the links between the land and the oceans. It will have a strong applied aspect regarding sea-level rise and coastal forecasting. As such, the work will contribute to a better understanding of the global environment and thereby to an improvement in human living conditions, especially for those at risk from coastal flooding