Winds from the south and south- 

 east, which are generally experi- 

 enced in the summer months, approach 

 a majority of the Keys at a right 

 angle to the islands and the reef 

 tract (Enos 1977, Marszalek et al. 

 1977). This wind assists the flood 

 tide in pushing water masses in a 

 northwest direction across the reef 

 tract and through the passes and 

 island channels into Florida Bay and 

 the Gulf of Mexico (Ginsburg 1956). 

 Because of the buffering action of 

 the outer reefs and short distance 

 to the islands, the wind-generated 

 waves rarely exceed a moderate chop 

 (Enos 1977). This wind tends to 

 "pile" waters up on the seaward side 

 of the Keys, accelerating the south- 

 east to northwest lateral seepage of 

 waters through the permeable lime- 

 stone (Chesher 1974). Concurrently, 

 the waters of Florida Bay tend to be 

 pushed up toward the mainland 

 (Ginsburg 1956, Turney and Perkins 

 1972). 



A vivid demonstration of these 

 summer winds occurred during an oil 

 spill off the Marquesas Keys (Chan 

 1976). The spill occurred approxi- 

 mately 42 km (26 mi) south-southwest 

 of these islands when an oil tanker 

 discharged 1,500 to 3,000 barrels of 

 a crude oil emulsion "clingage" into 

 the western edge of the Florida Cur- 

 rent. The spill moved northeast 

 with the Florida Current and pre- 

 vailing winds from the southeast, 

 thus driving the oil slick ashore 

 along a 48 km (30 mi) stretch of the 

 lower Keys from Boca Chica Key to 

 Little Pine Key (Chan 1976). 



During spring and fall the 

 resultant winds are from the east- 

 northeast. At this time the arcuate 

 nature of the islands and reefs be- 

 comes a particularly critical factor 

 in localized currents. Relative to 

 prevailing winds, the orientation of 

 the islands and reef tract shifts 



from north-northeast at Key Largo to 

 east-northeast at Key West. In the 

 upper Keys the wind's approach is 

 nearly perpendicular to the reef 

 tract and generally onshore. Fur- 

 ther down the Keys, in the middle 

 Keys and particularly into the lower 

 Keys, the predominant winds run 

 nearly parallel to the islands. 

 This alignment promotes a longer 

 fetch along Hawk Channel, creating 

 larger waves and more turbid waters 

 due to resuspension of fine calcare- 

 ous sediments (Griffin 1974, Enos 

 1977). The easterly component of 

 these winds continues to supplement 

 the flood tide flow in the middle 

 and upper Key channels, while in the 

 lower Keys the elongated shoals 

 lying perpendicular to the resultant 

 winds reduce the wind-driven flow 

 through the islands (Hanson 1980). 

 The effect on Florida Bay and the 

 water on the gulf side of the middle 

 and lower Keys is to push waters to 

 the gulf or to the west-southwest 

 (Koczy et al. 1960, Rehrer et al. 

 1967, and Turney and Perkins 1972). 

 The distal islands of the Tortugas 

 and Marquesas Keys experience west- 

 southwest wind-driven currents 

 supplementing the more southerly 

 oceanic flow of the eastern edge of 

 the Gulf Loop Current (Koczy et al. 

 1960, Rehrer et al. 1967, and Jones 

 et al. 1973). 



During the remainder of the 

 year from December to February, and 

 even the later fall months, synop- 

 tic-scale cold fronts pass through 

 the area bringing winds of a variety 

 of directions and speeds (Enos 1977, 

 Marszalek et al. 1977). Northeast 

 and north-northeast winds generally 

 prevail. These prevailing winds run 

 parallel to the upper Keys causing a 

 similar resuspension of sediments 

 which the middle and lower Keys 

 experienced in the fall and spring 

 seasons (Enos 1977). Florida Bay 

 waters are pushed in two directions: 



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