PROJECT GOALS TITAN'S LAKES AND SEAS ARE IMPORTANT PARTS OF ITS HYDROCARBON CYCLE AND THEIR SIZE SHAPE AND GEOGRAPHIC DISTRIBUTION MAY ENCODE A HISTORY OF TITAN'S CLIMATE AND SURFACE GEOLOGY. AT PRESENT WE ARE UNABLE TO READ THIS HISTORY WELL BECAUSE WE DO NOT KNOW WHAT GEOLOGIC MECHANISMS HAVE SHAPED THE LAKES AND SEAS. IT HAS BEEN PROPOSED THAT TITAN'S LAKES ARE KARST FEATURES SHAPED BY DISSOLUTION OF SURFACE MATERIALS. THIS HYPOTHESIS IMPLIES A DOMINANT ROLE FOR CHEMICAL EROSION UNLIKE MOST COASTS ON EARTH. THIS PROJECT WILL TEST THE ALTERNATE HYPOTHESIS THAT WAVE-DRIVEN MECHANICAL EROSION AND SEDIMENTATION HAVE SHAPED TITAN'S LAKES AND SEAS BY APPLYING THE THEORY AND METHODS OF TERRESTRIAL COASTAL GEOMORPHOLOGY TO CASSINI DATA. WE WILL SEARCH FOR EVIDENCE OF WAVEDRIVEN COASTAL EROSION AND SEDIMENT TRANSPORT BY COMPARING COASTAL EVOLUTION MODELS WITH MEASUREMENTS OF TITAN'S LAKES. THESE COMPARISONS WILL BE INFORMED BY ANALYSES OF TERRESTRIAL REMOTE SENSING AND FIELD OBSERVATIONS. METHODS WE WILL TEST THREE PREDICTIONS ARISING FROM THE HYPOTHESIS THAT WAVE-DRIVEN COASTAL PROCESSES HAVE SHAPED TITAN'S LAKES. FIRST BASINS IN STEEP TOPOGRAPHY SHOULD BE SHAPED DOMINANTLY BY COASTAL CLIFF EROSION WHEREAS BASINS IN GENTLY SLOPING TOPOGRAPHY SHOULD BE MORE PRONE TO SEDIMENT DEPOSITION AND RESHAPING BY ALONGSHORE SEDIMENT TRANSPORT. USING COASTAL EVOLUTION MODELS (CEMS) NUMERICAL MODELS THAT SIMULATE THE TIME EVOLUTION OF COASTLINE POSITION THROUGH EROSION AND SEDIMENT TRANSPORT WE WILL QUANTIFY HOW THE EVOLUTION OF LAKE SHAPE DEPENDS ON TERRAIN RELIEF LAKE SIZE AND CUMULATIVE WAVE ACTION. WE WILL TEST THIS FRAMEWORK BY COMPARISON WITH FIELD SURVEYS OF EROSION-DOMINATED AND REWORKING-DOMINATED LAKES IN NEW ENGLAND AND REMOTE-SENSING STUDIES OF SUCH SYSTEMS ELSEWHERE ON EARTH. WE WILL THEN MEASURE TITAN SHORELINE SHAPES FROM CASSINI SAR IMAGES COMBINED WITH AVAILABLE TOPOGRAPHY TO ASSESS WHETHER TITAN'S LAKE MORPHOLOGY IS CONSISTENT WITH DOMINANTLY MECHANICAL SHORELINE MODIFICATION. SECOND ELONGATE LAKE SHORELINES AFFECTED BY ALONGSHORE TRANSPORT SHOULD DEVELOP CHARACTERISTIC DEPOSITIONAL COASTAL LANDFORMS SUCH AS CAPES AND SPITS EVEN AS OTHER PARTS OF THE SHORELINE BECOME SMOOTHER. WE WILL APPLY CEMS TO TITAN LAKES THAT APPEAR TO CONTAIN CAPES AND SPITS COMPARING MODEL RESULTS TO CASSINI SAR IMAGES TO TEST WHETHER MODELED FEATURES FORM IN SIMILAR LOCATIONS AND WITH SIMILAR ORIENTATIONS. AS A CHECK WE WILL PERFORM THE SAME ANALYSIS ON SATELLITE IMAGES OF TERRESTRIAL LAKES. THIRD LOCAL WIND DIRECTION SHOULD AFFECT LAKE SHORELINE RESHAPING: UPWIND-FACING SHORELINES EXPOSED TO MORE WAVE ENERGY SHOULD BE MEASURABLY SMOOTHER THAN LEEWARD-FACING SHORELINES. WE WILL MEASURE DIRECTIONALLY DEPENDENT SHORELINE ROUGHNESS ON TITAN WITH A WAVELET-BASED TECHNIQUE USING LAKE SHORELINES MAPPED FROM CASSINI SAR DATA TO CREATE A GLOBAL MAP OF SHORELINE ASYMMETRY. IF WE FIND REGIONALLY CONSISTENT ASYMMETRY THESE TRENDS WILL BE COMPARED WITH ATMOSPHERIC GENERAL CIRCULATION MODEL (GCM) CALCULATIONS OF WIND DIRECTION AND SPEED. FOR COMPARISON WE WILL USE GLOBAL METEOROLOGICAL DATA TO PERFORM THE SAME ANALYSIS ON SATELLITE IMAGES OF TERRESTRIAL LAKES.