The influence of the Laurentian Great Lakes on the climate of surrounding regions is significant, especially in leeward settings where lake-effect snowfall occurs. Heavy lake-effect snow represents a potential natural hazard and plays important roles in winter recreational activities, agriculture, and regional hydrology. Changes in lake-effect snowfall may represent a regional-scale manifestation of hemispheric-scale climate change, such as that associated with global warming. This study examines records of snowfall from several lake-effect and non-lake-effect sites throughout most of the twentieth century in order to 1) determine whether differences in snowfall trends exist between these settings and 2) offer possible linkages between lake-effect snow trends and records of air temperature, water temperature, and ice cover. A new, historic record of oxygen isotope [␦ 18 O ] data from the sediments of three eastern Finger Lakes in central New York is presented as a means (CaCO ) 3 of independently assessing changes in Great Lakes lake-effect snowfall. Results reveal a statistically significant increasing trend in snowfall for the lake-effect sites, whereas no trend is observed in the non-lake-effect settings. The Finger Lake oxygen isotope record reflects this increase in lake-effect snow through a statistically significant trend toward lower ␦ 18 O values. Records of air temperature, water temperature, and lake ice suggest that (CaCO ) 3 the observed lake-effect snow increase during the twentieth century may be the result of warmer Great Lakes surface waters and decreased ice cover, both of which are consistent with the historic upward trend in Northern Hemispheric temperature due to global warming. Given projected increases in future global temperature, areas downwind of the Great Lakes may experience increased lake-effect snowfall for the foreseeable future.

Repeat geodetic surveys show uplift of the Monroe and Wiggins anticlines in Louisiana and Mississippi. There are deformed Quaternary terraces, which indicate long-term deformation in the valleys of the alluvial rivers that cross these structures, and there are floodplain and channel convexities that provide evidence of modern deformation. In addition, the channels show significant variations of morphology (sinuosity, gradient, and depth) and behavior appropriate to reaches of increased and decreased valley slope. These alluvial rivers are adjusting to modern deformation and their adjustment confirms two geodetic leveling anomalies.

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Oxygen isotope values of meteoric precipitation (δ18O) are strongly influenced by water vapor source and trajectory history, and can therefore be used as a tool for the reconstruction of atmospheric circulation. However, this approach requires an understanding of how differing patterns of atmospheric circulation influence precipitation δ18O. This study examines the relationship between atmospheric circulation and winter precipitation δ18O in central New York State. Circulation back trajectories, weather maps, and δ18O values for 132 precipitation samples were examined to determine the circulation type for each event. Lake‐effect precipitation, which generated the lowest δ18O values, featured low pressure over New England and northwesterly flow over the Great Lakes. Events with the highest δ18O values were associated with low pressure north of New York and strong southerly flow within the warm sector. Less frequent were the Atlantic coastal and warm frontal overrunning events, both of which yielded relatively depleted precipitation.