[Triumf-seminars] TRIUMF Colloquium today at 14:00

[postmaster at admin.triumf.ca]

Date/Time: Thu 2009-11-19 at 14:00

Location:  Auditorium          

Speaker:   Diana Varela (University of Victoria)

Title:     Application of the radioactive silicon isotope 32Si for oceanographic research

Abstract: Diatoms, a group of aquatic microalgae, are one of the largest contributors to primary production in the ocean accounting for up to 40% of annual marine carbon fixation and responsible for ~20% of the carbon fixed through photosynthesis on Earth.  Because diatoms are the largest consumers of dissolved silicon (Si) in the oceans, they control the cycling of Si and, after they die and sink, contribute significantly to the downward flux of biogenic silica, nitrogen and carbon in most oceanic regions.

The development of the radioactive 32Si technique for the measurement of diatom production in the 1990s was revolutionary for oceanography since it allowed rapid and relatively uncomplicated measurements, it was suitable for work with diatom cultures, but most importantly it was the only practical methodology to be used onboard oceanographic ships. Unfortunately, 32Si is currently out of production. The availability of this isotope would have a tremendous impact on our understanding of carbon fixation, export and sequestration and modeling of biogeochemical cycles in the ocean.

Stimulants available 15 minutes before the talk.

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