IMPACTS OF HURRICANE-ANDREW ON CARBONATE PLATFORM ENVIRONMENTS, NORTHERN GREAT-BAHAMA-BANK

The northern (most energetic) quadrant of Hurricane Andrew (August 199 2) passed over leeward-margin sand waves, bank-top sand shoals, reefs, and low islands of Great Bahama Bank for which an extensive prestorm data base exists. A reconnaissance survey seven weeks after Hurricane Andrew evaluated storm impacts on these bank-top settings. Resurveyed seismic profiles showed that positions, dimensions, and orientations o f platform sand bodies were unchanged relative to fixed bedrock featur es. Surveys of reef communities indicated only minor storm-related dis turbance. Coral bleaching may be due to storm-induced environmental st ress. In addition, storm-wave plucking of boulders from emergent rocky cays resulted in localized crushing of reef biota. On low islands, be ach erosion and storm surge were insignificant, and storm damage to Ca suarina forests was minor and substrate-specific. Observed minimal hur ricane impacts on northern Great Bahama Bank environments lying 10-75 km from the hurricane eye are reconciled by analysis of meteorological data, which show significant weakening of the storm (expressed as a r ise in central barometric pressure of approximately 20 mbar) during pa ssage across the bank-top. This study demonstrates the importance of s pecific dynamic aspects of hurricanes (e.g., varying intensity, streng th, size, forward speed, duration) which influence their geologic pote ntial, even over relatively short distances along the storm track of a n individual hurricane.