Gulf of America high-resolution oxygenation

We plan to collect new sediment cores from the northern Gulf of Mexico dead zone, with a focus on the dissolved oxygen gradient based on the annual shelf-wide dead zone survey ( http://www.gulfhypoxia.net ). Two sets of sediment cores will be collected on the eastern section of the dead zone (dominated by the Mississippi River influence) and the central section of the dead zone (dominated by the Atchafalaya River influence) to investigate likely different local oxygen responses under different river dynamics. With the new coring material, we aim to study the following research questions: 1. How has the northern GOM dead zone (intensity and frequencies) evolved on interannual to centennial timescales in the Common Era (last 2000 years)? 2. What is driving dissolved oxygen variations in the dead zone (e.g., productivity, ocean circulation, and/or stratification)? 3. How will the northern GOM dead zone respond to future climate change and river dynamics considering both natural and anthropogenic forcings (e.g., land use, Mississippi River delta evolution, and eutrophication) on a long term (e.g., multi-decadal to centennial timescales)?