Relative sea-level changes from near-, intermediate- and far-field locations and their implications for geophysical modeling and 20th century ice sheet-ocean interactions

The goal of this research is to synthesize a database of sea-level observations in a systematic and rigorous fashion for the Atlantic coast of North America, Bermuda and the Caribbean for the last 20,000 years. The database will facilitate the interpretation of relative sea-level (RSL) change on a regional scale and enable the tuning and refinement of Earth system models that focus on predicting RSL change and its spatial variability. The database consists of 60 study locations, permitting a suite of geophysical parameters to be constrained. Earth?s lower mantle viscosity will be defined by near-field and ice-margin RSL data from the Atlantic coast of Canada and northeastern United States while the upper mantle viscosity will be reliant on intermediate-field RSL data from the mid Atlantic. Far-field RSL data from the southern United States and Caribbean will constrain ice-equivalent meltwater input. The database will be further used to decontaminate 20th century rates of sea-level rise from tides gauges to reveal spatial variability related to ocean mass and volume changes.

At the heart of this project is a database of sea level from North America (the Atlantic coast of Canada and the United States) and the Caribbean that stretches back 20,000 years. This will be significant to a number of disciplines in the Earth sciences. For example, careful reconstruction of sea levels from the past will reveal the contribution from land-based ice to sea-level change during deglaciation after the last ice age. In addition, the data will provide vital constraints on key parameters in geophysical models of the Earth that are used in a variety of other applications (e.g., plate tectonics, glaciology and paleoclimate). Overall, the observations will extend the time range of comparisons with historical and present-day changes. Consequently, this research promises to increase our understanding of the driving mechanisms of sea level change and enhance our predictions of 21st century sea-level rise. The research will also provide an important and unique contribution to the assessment of national hazards with respect to sea-level rise and coastal responses.