Collaborative research: Sea-level variability during the Common Era

Harvard University, Cambridge MA

Investigators

Abstract

Part 1 The research to be performed will help inform projections of regional and global mean sea-level rise as well as contribute to the climate change impacts assessment. The investigators will reconstruct the relative sea-level variability during the Common Era (~ last 2000 years) along the Atlantic coasts of Newfoundland and Florida and the Florida Gulf coast at higher resolution and in greater detail than is now available. The investigators will work with the National Estuarine Research Reserves Coastal Training Program, the Rutgers Climate and Environmental Change Initiative, and Rutgers Cooperative Extension program to develop applied use of the information from this project. The project seeks to offer an Earthwatch IGNITE project to high school students to provide them with the opportunity to participate in field trips and experience the scientific research firsthand. Results will be showcased to the local community at Tufts Research Days and Rutgers Day, annual events held on campus which will allow the public to engage with the researchers. Undergraduate students will be involved in the research, in both field work and laboratory analysis. Two early-career investigators will be supported by this work and partial support will be provided for postdoctoral scientists from Rutgers University and Tufts University and for graduate students at Rutgers University and the University of Rhode Island. Part 2 The proposed work will use geological proxies to reconstruct Common Era relative sea level variability along the Atlantic coasts of Newfoundland and Florida and the Florida Gulf coast at ~<0.2m vertical resolution and decadal-to-centennial temporal resolution. To estimate global mean sea level and the spatio-temporal field of eastern North American Common Era relative sea level, the new relative sea level reconstructions will be combined with existing relative sea level reconstructions and tide gauge measurements in an empirical Bayesian statistical framework. The data and statistical model would be used to test the following research questions: 1) whether sea level along the North American Atlantic and Gulf coasts has varied as a direct consequence of a warmer climate during the Medieval Climate Anomaly and cooler climate during the Little Ice Age; 2) whether spatial variability of sea level during the Common Era can be attributed to static-equilibrium effects of land ice changes and/or ocean dynamics; 3) whether Earth models with depth-varying Earth structure are sufficient to capture the spatio-temporal geometry of Glacial Isostatic Adjustment along the east coast of North America; and 4) whether the rate of sea-level rise since ~1850 in eastern North America has been greater than any other centennial trend during the previous two millennia. The proposed work is of significant societal relevance as it will provide more accurate data for use in the projections of regional and global mean sea-level rise as well as contribute to the climate change impacts assessment.