Robert Aller, Ph.D
Stony Brook University, School of Marine and Atmospheric Sciences
Worms' World: Biogeochemical Heterogeneity and Dynamics of the Seafloor as Revealed by 2-D Optical Sensors
Wednesday - February 18, 2009
Pacific Forum – 3:00 p.m.
Despite its rather ordinary appearance, the muddy seafloor plays a central role in oceanic biogeochemical cycling. The activities of its inhabitants, such as worms and molluscs, create highly dynamic and geometrically complex reaction patterns, and promote exchange of nutrients and metals between the seabed and overlying water. Planar optical sensors provide a means to reveal and quantify the time-dependent, heterogeneous distributions of solutes within sediments in 2 and 3 dimensions. We have developed a suite of planar optodes (presently pH, carbon dioxide (CO2), hydrogen sulfide (H2S), oxygen (O2), iron 2+ ion (Fe2+)) suitable for environmental and experimental applications. As shown by a range of examples from both laboratory microcosms and in situ, these sensors allow unprecedented insights into biogeochemical processes in sedimentary deposits.