Final answer:
Warm ocean currents, the latent heat of fusion, and the ocean's high heat capacity collectively work to prevent harbors from freezing by moderating coastal temperatures and slowing down temperature changes.
Step-by-step explanation:
Summer temperatures in the 60s, winter temperatures well below freezing, and warm ocean currents work together to prevent harbors from freezing due to several geophysical factors. First, the oceans are tremendous reservoirs of heat energy, which they distribute via currents. These warm currents, moving from warmer to cooler regions, can moderate the climate of coastal areas and prevent sudden drops in temperature.
Furthermore, the latent heat of fusion of water plays a critical role in maintaining temperatures above the freezing point. As water cools and begins to freeze, it releases heat, which helps to keep the surrounding air and water temperature from plummeting rapidly. This slow decrease in temperature protects harbors and coastal regions from harsh freezing conditions.
Lastly, due to the high heat capacity of water compared to land, oceans heat and cool more slowly. This 'heat inertia' means that coastal areas can enjoy milder winter temperatures as the ocean slowly releases heat absorbed during the summer. Inland areas, on the other hand, lack this moderating influence and experience more extreme temperature variations. Similarly, coastal environments benefit from this effect, leading to more moderate climates compared to interior regions.