The lingering effects of deglaciation
27 March 2009
Our oceans may still be feeling the after effects of ‘chemical weathering’ from the last deglaciation, says Derek Vance from the University of Bristol.
Rivers are a dominant source of many elements and isotopes in the ocean, but this input from the continents is not perfectly balanced by the loss of these elements and isotopes from the ocean.
In a paper published in Nature, Vance and colleagues offer an explanation for the observed imbalance in marine geochemical budgets. Our modern-day estimates of river flux are broadly accurate, say the authors, but a pulse of rapid chemical weathering initiated at the last deglaciation that ‘feeds’ the riverine flux with elements and isotope,s has not yet decayed away.
They find that taking into account this suggested temporal variability in riverine fluxes largely resolves the long-standing chemical and isotopic mass imbalances in the ocean.
For further details see the full article.