PhD: Holocene sea-level change in south-central Chile

There is a paucity of relative sea-level data from Chile, and where data does exist there is a discrepancy between observations and models. Glacial isostatic adjustment models suggest relative sea-level has been falling along the Pacific coast of South America since the mid-Holocene, but there are field observations to suggest sea-level rise over the last millennium. Such sea-level data are necessary to constrain these models and to try to better understand the drivers of Holocene sea-level change.

There are a number of different causes of sea-level change in this area, including great earthquakes, ongoing tectonic deformation, isostatic response since the last glacial maximum, neoglacial forebulge migration and collapse, and global eustasy. We have identified sites for sea-level reconstruction that will potentially be able to provide some key constraints on models, on the timing and magnitude of the mid-Holocene highstand, as well as directing where evidence for historic great earthquakes may be preserved. The latter will form a key additional part of this project, working on reconstructing abrupt relative sea-level changes caused by great earthquakes.

Palaeoseismic research has advanced significantly in Chile since the 2010 Maule earthquake, but there are still relatively few sites where there are quantitative reconstructions of deformation for historic earthquakes. Such records are essential for providing long-term perspectives on the recurrence, magnitude and variability of earthquakes occurring along the Chilean megathrust.

You will use a range of approaches to develop a relative sea-level curve for south-central Chile, including tidal marsh sediments and raised marine deposits. The project will involve fieldwork to Chile, and will involve using a variety of field, microfossil (diatoms), laboratory, dating, and analytical techniques. Full training will be given.