Byrd Center Seminar:
Dating ice cores with time-varying atmospheric gases
Prof. Jeffrey Severinghaus, Scripps Institution of Oceanography, UC San Diego
Friday, July 9, 2021, 11 AM
Scott Hall Room 177 (The Learning Center)
Register to attend via Zoom
Abstract:
The atmosphere is well-mixed on timescales longer than a year. This means that gases and their isotopes should be the same at any point on Earth, for a given age. Air bubbles in ice cores typically contain atmosphere that was trapped over timescales of decades, ensuring that the bubble gas compositions represent samples the well-mixed atmosphere. Stable isotopes of atmospheric O2 and methane concentrations are two well-known gases often used for dating ice cores. However, melting and refreezing on the surface of low-latitude glaciers, along with respiratory consumption of O2 by microbes in the snow, can bias the ages obtained. He will discuss recent progress in making corrections for respiration and melt in the Guliya summit record.
