Inception of a global atlas of Holocene sea levels

Abstract

Determining the rates, mechanisms and geographic variability of sea-level change is a priority science question for the next decade of ocean research. The HOLocene SEA-level variability (HOLSEA) working group is developing the first standardized global synthesis of Holocene relative sea-level that incorporates full consideration of vertical and temporal uncertainty for each sea-level index point, including uncertainties associated with the relationship of each indicator to past sea level and the methods used to date each indicator. HOLSEA aims to: (1) estimate the magnitudes and rates of global mean sea-level change during the Holocene; and (2) identify trends in spatial variability and decipher the processes responsible for geographic differences in relative sea-level change. The global atlas includes over 12,000 sea-level index points and limiting data from a range of different indicators across seven continents from the Last Glacial Maximum to present. The global atlas will be made available in a special issue of Quaternary Science Reviews and archived on NOAA’s National Centers for Environmental Information (NCEI). The global atlas now includes sea-level data from: 1. Near-field regions (Atlantic Canada, Greenland, the British Isles, the Russian Arctic, Antarctica); 2. Intermediate-field regions (Pacific, Gulf, Atlantic and Caribbean coasts of North America, western Europe, the Mediterranean, New Zealand); 3. Far-field regions (Atlantic South America, South Africa, India, Sri Lanka, the Maldives, Southeast Asia, China, Australia). Here we combine near-, intermediate-, and far-field data along a pole-to-pole transect (Greenland, North American Atlantic coast, Caribbean, South American Atlantic coast and Antarctica) to illustrate the advantages of applying a spatio-temporal empirical hierarchical statistical model to describe the spatial variability in relative sea level and its rates of change. By comparing these records across a transect that spans a range of ‘fingerprints’ from land-based ice sheets, we have the potential to isolate ice-sheet contributions to Holocene RSL changes