The sediment budget of Great Bahama Bank—Earth’s largest modern carbonate platform

Melding remote sensing, field sampling, and seismic data, we broadly quantify the sediment budget of Great Bahama Bank (GBB). This isolated carbonate platform is unique in the modern world because of its immense size and its abundance of non-skeletal sediments, making it an analog for the giant platforms of the geologic past. Whereas previous studies focused on singular aspects of the budget, such as sediment production, export, or accumulation, we reconcile all three. We contend that annually, GBB produces 0.93−7.81 × 1013 g of sediment, exports 0.74−8.79 × 1013 g, and accumulates 2.24−57.31 × 1013 g. Cores and seismic data confirm that GBB has tracked rising sea level since flooding 6.7 k.y. ago, necessitating, at minimum and on average, a balanced budget. To perform as such, we contend that the sediment producers atop GBB must have produced at, or near, their maximum modern-day capacity. Our study therefore challenges the notion that non-reefal platforms grossly overproduce sediment. The budget of the Holocene GBB is apparently more precariously balanced than previously thought and may conceivably fail to track future sea-level rise if impeded by changing climate.