Global Carbonate

To interface with whole-earth scale models, such as climate and circulation models, ocean substrates data has been synthesized from dbSEABED at the global scale. The resolution however, is low (best, 0.1 degrees) - as for most of the models. A parameter of high interest is the carbonate content of the bottom. However, a global synthesis of any main dbSEABED parameter or component/feature is now possible (see lists HERE).

The carbonate synthesis follows early work by Archer (1996, "An atlas of the distribution of calcium carbonate in sediments of the deep sea." Global Biogeochemical Cycles 10, 159-174), but has a number of changes: (i) the amount of data available is much greater; (ii) the core-top criterion is relaxed (based on arguments involving bioturbation, erosion, managment of core overpenetrations in underlying database); (iii) rock areas bare of sediment (such as the spreading ridges) and Fe-Mn nodule areas are accounted for;  (iv) shallow-water areas - which also play a role in ocean carbonate chemistry (see Andersson, AJ & Mackenzie FT.  2012.  "Revisiting four scientific debates in ocean acidification research", Biogeosciences. 9, 893-905) are mapped. Prime amongst the shallow water areas is the "Coral Triangle" area of SE-Asia, Indonesia. Some geographic data on the regional distributions of skeletal carbonate types and mineralogies are also available from the project.

The mapping suggests lower carbonate contents overall than mapped in earlier works. This may affect modeled budgets for earth-system carbon dioxide and outcomes for ocean acidification.

The synthesised data are rapidly being extended, and can be generated on request from the latest version of the full dbSEABED data holdings.

Graphic: Global-scale carbonate contents, interpolated using Radial Basis Function methods. Deep blue to dark red, 0 to 100%. (Dated Aug 2014)