Marine Sciences

Alicia Wilson 

University of South Carolina

Wind, submarine groundwater discharge, and biogeochemical inputs to the ocean

The field of submarine groundwater discharge (SGD) was launched in the 1990s by the remarkable discovery, via naturally-occurring isotopic tracers, that saline groundwater was discharging to the South Atlantic Bight in very large volumes. Subsequent studies confirmed that saline groundwater discharges to the Atlantic Ocean in volumes that rival river discharge, and it is now clear that the global nutrient contributions of saline submarine discharge exceed those of river discharge. Acceptance of the importance of these fluxes was slow in coming, however, because the mechanism and location for this saline discharge remained a mystery for more than 20 years. We used heat as a tracer to identify clear pulses of groundwater discharge much farther from shore (10-15 km) than described by conventional conceptual models. This work demonstrates that wind events are major drivers of seawater-groundwater exchange kilometers from the shoreline, and this exchange drives major exports of nutrients from saline submarine groundwater to the ocean. Isotopic analyses confirm that this exchange supplies “new” nitrogen to the ocean (i.e. it is not recycled from the water column). This work supports major rewrites of standard hydrologic cycle diagrams, conceptual models for coastal groundwater flow, and nutrient budgets for the coastal oceans.

Host: Julie Granger
Time & Date: 11:00 am, Friday, October 11, 2024
Place: Lowell Weicker Building, Seminar Room 103 (or WebEx)

Request Seminar Information

Cancellation & Additional Seminar Details

If you are an individual with a disability and need accommodations, please contact 860-405-9152 or email marinesciencesseminars@uconn.edu.

https://marinesciences.uconn.edu/seminar/brownbag1248/

Please email Katie for the link to join online. 

https://marinesciences.uconn.edu/seminar/brownbag1248/

Please email Katie for the link to join online.

Xingchen Tony Wang

Boston College

Ocean fertilization, carbon sequestration, and deoxygenation: From Miocene to Anthropocene

Ocean fertilization, which aims to enhance primary productivity by introducing limiting nutrients (such as iron, nitrogen, or phosphorus) into nutrient-poor surface waters, is currently being explored as a technology for ocean-based carbon dioxide removal. However, the efficacy of this approach in sequestering carbon in the deep ocean remains uncertain. In addition, the increased export of organic matter to subsurface waters could exacerbate deoxygenation, potentially expanding ‘dead zones’ where fish and animals cannot survive. In this presentation, I will discuss several historical case studies that may shed light on these issues, including: (1) ocean phosphorus fertilization and the origins of the largest ‘dead zones’ in the eastern Pacific Ocean eight million years ago; (2) ocean iron fertilization during the Pleistocene ice ages and its impact on atmospheric carbon dioxide; and (3) anthropogenic nitrogen fertilization and its effects on ‘dead zones’ in the northern Gulf of Mexico.

Host: Julie Granger
Time & Date: 11:00 am, Friday, October 25, 2024
Place: Lowell Weicker Building, Seminar Room 103 (or WebEx)

Request Seminar Information

Cancellation & Additional Seminar Details

If you are an individual with a disability and need accommodations, please contact 860-405-9152 or email marinesciencesseminars@uconn.edu.