The Finger Lakes region of Upstate New York is characterized by eleven long, narrow, and deep lakes. The question of which one is the largest often arises, but the answer depends entirely on the metric used for comparison. Two lakes, Seneca and Cayuga, dominate the region. The misconception that one lake is definitively the biggest stems from the fact that they each hold different records for size.
How Is “Largest” Determined
The size of any lake is measured using three primary metrics: surface area, maximum depth, and total water volume. Surface area is the two-dimensional measure of a lake’s length and width, indicating how much land it covers. Maximum depth measures the deepest point from the surface to the lake floor. Total volume, often considered the most comprehensive measure, combines surface area and depth to calculate the total amount of water held within the basin. Different lakes hold the record for each measurement, meaning a lake can be long but shallow, or short but deep, resulting in varying volumes.
Seneca Lake The Deepest and Highest Volume
Seneca Lake holds the record for the largest overall size due to its substantial water volume. It is estimated to contain approximately 4.2 trillion gallons of water, which is roughly half of all the water found in the eleven Finger Lakes combined. This immense volume is a direct result of its profound depth, which reaches a maximum of 618 feet. The lake floor extends 200 feet below sea level, making it the deepest lake entirely within New York State. This great depth and volume give Seneca Lake a massive heat-storage capacity, which helps moderate the surrounding air temperature and supports the region’s vast wine industry.
Cayuga Lake The Longest and Widest
Cayuga Lake is the longest of the Finger Lakes, stretching just under 40 miles. Its surface area, at approximately 66.41 square miles, is marginally smaller than Seneca Lake’s 66.9 square miles, making it the second largest by surface coverage. Despite its impressive length, Cayuga Lake is significantly shallower than its neighbor. Its maximum depth is 435 feet, which is notably less than Seneca’s maximum depth. Because it is shallower, its total water volume is the second largest in the region, falling far short of the amount of water held by Seneca Lake.
The Glacial Origin of the Finger Lakes
The distinct, elongated shape and profound depth of the Finger Lakes resulted from massive ice sheets during the Pleistocene glaciation. Millions of years ago, the area consisted of northward-flowing rivers and V-shaped valleys. Continental glaciers advanced southward, carving and scouring the existing river valleys, deepening and widening them into characteristic U-shaped troughs. The deepest parts of these troughs, such as the basins of Seneca and Cayuga, were cut hundreds of feet into the bedrock. As the glaciers retreated, they left behind piles of debris called terminal moraines, which acted as natural dams, blocking the flow of pre-glacial rivers and allowing the valleys to fill with meltwater.