40 research outputs found
Flux of Suspended Calcium Carbonate (CaCO3), Fanning Island Lagoon
A plume of turbid, CaCO3-laden water (0.24 mg/liter) is expelled
from English Harbor, Fanning Atoll, on outgoing tides. On incoming tides, the
concentration is 0.36 mg CaCO3/liter. At the two other passes of the atoll, incoming
CaCO3 concentrations also are higher than outgoing concentrations. Lagoon waters
contain 1 mg CaCO3/liter in the clear central portion of the lagoon and 4 mg
CaCO3/liter elsewhere. Offshore concentrations out of the plume area are 0.03 mg
CaCO3/liter. The lagoon and plume CaCO3 material is reef-derived detritus (aragonite
and high-Mg calcite). Offshore CaCO3 particles are primarily coccoliths
(low-Mg calcite).
During a 24-hour survey 10 tons of suspended CaCO3 were transported into the
lagoon. It is likely that the English Harbor plume represents little or no sediment
loss from the lagoon.
The plume debris is interpreted to be material produced on the outside fringing
reefs, sucked into the lagoon on incoming tides, and subsequently expelled. Production
of CaCO3 in the lagoon may be filling the lagoon faster than sea level is rising
Fanning Island expedition, July and August 1972
"Prepared for NATIONAL SCIENCE FOUNDATION UNDER GRANT GA313111