SEA-LEVEL RESEARCH

My research produces relative sea-level reconstructions at a range of temporal and spatial scales to determine the driving mechanisms behind past, present, and future changes. Active research themes include:

  1. High-resolution (century and decimeter scale) relative sea-level reconstructions for the past ~3000 years
    Understanding of sea-level variability during this period is limited and the response to known palaeoclimate deviations such as the Medieval Climate Anomaly, Little Ice Age and 20th century warming is unknown. These records are a benchmark against which to compare recent trends and help to calibrate predictive models by connecting global mean sea-level change to global mean surface temperature.
  2. Holocene sea level change in Micronesia
    Geophysical models predict that far-field sites such as Micronesia experienced a mid-Holocene high stand and therefore relative sea level fall during the past ~5000 years. This pattern hinders efforts to produce detailed relative sea level reconstructions in the tropics. However, coastal sediment on basaltic islands in Micronesia records continuous relative sea level rise (as recognized by early work searching for an “ocean dipstick” by Art Bloom for example) because of ongoing subsidence. These islands therefore provide a unique opportunity to build detailed records of late Holocene sea level change and thermos-tectonic processes in the tropical Pacific.
  3. Paleocean dynamics
    Changes in the strength and/or position of ocean currents redistribute ocean water on timescales from hours to centuries. This driving mechanism results in a characteristic spatial pattern of regional sea-level change. I am using relative sea-level reconstructions in the North Atlantic Ocean to identify and quantify late Holocene trends in ocean circulation including changes in Atlantic Meridional Overturning Circulation.
  4. Urban sea-level change
    Sea-level rise poses a hazard to the intense concentrations of population and infrastructure that are increasingly located at the coast. However, almost all existing sea-level reconstructions come from rural locations. I am reconstructing sea-level changes in New York City and Boston to develop a paleoenvironmental history for these cities and local projections for future rise.
  5. Wetlands and sea-level rise
    Healthy wetlands (salt marshes and mangroves) make our coastline ecologically and economically resilient to the hazards posed by storms and extreme water-level events that occur on top of rising sea level. Furthermore, they are increasingly recognized as key sinks of "blue carbon". The sediment buried beneath coastal wetlands preserves a record not only of sea-level change, but also of how these valuable ecosystems responded to past changes in sea level and climate. This offers an insight into how our coastal wetlands might respond to the rates and amount of sea-level rise expected in coming decades and centuries.