What causes a storm surge?

A storm surge is primarily caused by the combination of air pressure changes and strong winds during storms, particularly hurricanes and tropical storms. When a storm approaches, it creates low atmospheric pressure in the center of the storm. This decrease in pressure allows the sea surface to rise. Concurrently, the strong winds associated with the storm push water towards the coastline. The combination of these factors results in elevated water levels, which can lead to significant inundation in coastal areas.

Heavy rainfall combined with high tide, the option that suggests another possibility, can contribute to flooding but does not specifically create a storm surge. Earthquakes under the ocean are responsible for tsunamis rather than storm surges. Melting ice caps in polar regions contribute to long-term sea level rise, but they do not directly factor into the phenomenon of storm surge, which occurs due to immediate atmospheric and wind conditions during a storm event. Understanding these dynamics is crucial for effective floodplain management and disaster preparedness.