below normal for most of the month. Intense frontal systems moved into the area Jan 
10 and 16, causing air temperature minima over Florida Bay of 2.2 and 5.3°C, 
respectively, and wind speeds in excess of 15 m sec' 1 at Key West. Florida Bay water 
reached temperatures of 9.0°C. The effects of the January 16 frontal passage on 
shallow bank and Bay environments is shown on a NOAA-6 satellite image. 
1981 
Walker, N. D., H. H. Roberts, L. J. Rouse, and O. K. Huh (1982) Thermal history of reef- 
associated environments during a record cold-air outbreak event. Coral Reefs . 1:83-7. 
Several polar continental air masses intruding into the south Florida/northern Bahama 
Bank region during January 1981 caused record low air temperatures and rapid chilling 
of extensive shallow-water carbonate systems. Numerous ‘coral kills' along the 
Florida reef tract and massive fish mortalities in Florida Bay were attributable to 
unusually cold waters generated at this time. Thermal evolution of Florida Bay/Florida 
reef tract and northern Bahama Bank waters from 8 to 21 January was assessed from 
thermal infrared data acquired by the NOAA-6 environmental satellite, in situ water 
temperatures, local meteorological data, and a computerized heat flux model. Field 
observations and laboratory experiments identify 16°C as a thermal stress threshold 
for most reef corals. Temperature corrected digital satellite data indicated that water 
temperatures below 16°C were generated in Florida Bay and on Little and Great Bahama 
Banks during a 10-day period in January. Lowest temperatures on the Florida reef 
tract resulted from offshelf transport of Florida Bay water through major tidal 
channels. Offshelf movement of bay water is driven primarily by strong northerly 
winds, density gradients, and tidal pumping. Absence of reef development opposite 
major tidal passes along the Florida reef tract and aperiodic coral kills along bank 
margins can be attributed to this process, which has probably had a limiting influence 
on Holocene reef development in these areas. 
1981 0 
Woodroffe, C. D. (1981) Mangrove swamp stratigraphy and Holocene transgression, Grand 
Cayman Island, West Indies. Mar. Geol. . 41 (3/4):271-94. 
[DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] The island of Grand Cayman, in 
the western Caribbean, has an extensive mangrove swamp vegetation. Numerous cores 
have been taken in and adjacent to these swamplands, and these reveal that the swamps 
are generally underlain by a transgressive sequence of sediments. The basal unit of this 
sequence consists of a laminated or non-laminated crust, formed in a subaerial 
environment. Locally, these crusts are overlain by plastic mud, deposited in 
seasonally-flooded environments. Mangrove peat forms the upper unit of the 
transgression within most of the swamplands, overlying the other units where these 
are found, and reaching thicknesses of more than 4 m. The final stage of marine 
incursion is recorded to the east of North Sound, where, in water depths of 10 - 200 
cm, shelly mud occurs overlying mangrove peat. In contrast to this, to the west of 
North Sound, there is a regressive sequence in which shelly marl underlies a localized 
sea grass peat and mangrove peat. This regressive sequence records local progradation 
of mangroves into marine environments. The transgressive sedimentary sequence on 
Grand Cayman is similar to transgressive sedimentary sequences described from the 
Florida Everglades-mangrove complex, Florida Bay and the Belize Shelf. On Grand 
Cayman, however, the stratigraphy is less complex because there are not extensive 
freshwater peat-forming environments, or intertidal and supratidal carbonate 
environments. Samples of mangrove peat were collected from the peat/bedrock 
interface along a surveyed profile across Barkers Peninsula on Grand Cayman. 
Radiometric dating of these implies that sea level was approximately 185 cm below the 
present level at least 2100 yrs BP. Comparison of these dates with dates on mangrove 
264 
