When a hurricane approaches land, tremendous damage can occur to coastal cities and towns. Hurricanes impact natural environments along a coast too. Huge amounts of beach sand are moved from place to place. Even large boulders can be carried in the powerful surge of ocean water. High winds can topple trees. And low-lying areas are often flooded. The amount of damage depends on the strength of a storm and what it hits.
As a storm moves towards a coast, it can cause sea level to rise as much as 20 or 30 feet. Wind from the storm pushes ocean water towards the land. The low pressure of the storm also allows the water level to creep higher. The water piles up with nowhere to go but onto land when it gets to the coast. The rising water, called storm surge, can submerge low-lying areas and towns along the coast. Combined with the crashing waves of the storm, the storm surge can cause demolishing docks, houses, roads, and erode beaches. The floods from storm surge usually lasts for a short time, usually just a few hours, but can cause a tremendous amount of damage. When storm surge happens at high tide, there is even more flooding.
As a hurricane approaches a coastline, scientists use a computer model called SLOSH (Sea, Lake, and Overland Surges from Hurricanes) to try to predict how much storm surge will occur. The model takes into account important factors that affect storm surge include the speed of winds in the storm, the distance that those winds travel over the ocean, how the hurricane approaches the coast (whether it is a direct impact or hits at an angle), and the shape of the coast and the ocean floor.
After a hurricane hits a coastal area, it can travel inland. At this point, the storm has typically weakened, but it can still cause damage. Torrential rains from the storm can cause rivers to flood their banks and mudslides to form.
Around the world, about 10,000 people die each year in hurricanes and tropical storms. While hurricanes have intense winds, waves and even tornadoes, floodwaters are their most dangerous aspect. If a hurricane is approaching the area where you live, check for hurricane warnings. Evacuate to a safe location if it is recommended. If you live in an area prone to hurricanes, consider making a hurricane safety kit. The Hurricane Preparedness web site at the U.S. National Hurricane Center offers tips on how to prepare for a hurricane.
When a hurricane is over the ocean and far from land, they are still a hazard to boats at sea. Before modern weather forecasting, hurricanes were the cause of many shipwrecks including several in the Bermuda Triangle, an area known for disappearing ships. But with forecasting and warning systems, boats can steer clear of hurricanes. Unlike boats, oil and gas platforms over the water are unable to move out of harms way and can be damaged by the fierce wind and waves.