Monday, 29 October 2012 08:27
The wind is howling and the trees are swaying, but Amy and I are safe and sound, waiting for Hurricane Sandy to hit the New Jersey coast. We have met some wonderful, friendly families who have invited us into their homes to weather the storm. The first family that we met was forced to evacuate their home because of the threat of flooding, so we have moved in with another family that lives on high ground several miles from the ocean. The hurricane is not predicted to arrive for another 12 hours, but many homes and businesses have already been flooded and damaged. The storm is predicted to cause over a billion dollars in damage, many people’s houses will be destroyed and millions of people will be negatively impacted by Hurricane Sandy. However, through our journey across North America we have learned that looking for the positive things in all situations is important. So, the question we are trying to answer in this week’s Notes From the Trail is, why do hurricanes happen and what are the benefits of a hurricane.
The predicted path of Hurricane Sandy. Image by U.S. National Oceanic and Atmospheric Administration
What is a hurricane and how do they form?
A hurricane is an intense, rotating storm that forms in tropical oceans. The winds in a hurricane are 75 miles per hour or more. Hurricanes are generally smaller than storms in mid-latitudes, typically about 300 miles in diameter. Hurricanes form over really warm ocean water of 80°F or warmer. Plus, the wind must be blowing in the same direction and at the same speed to force air upward from the ocean surface. Winds flow outward above the storm allowing the air below to rise. The air cools off very quickly as it rises above the warm ocean. Hurricanes usually form between 5 to 15 degrees latitude north and south of the equator. The Coriolis Force is needed to create the spin in the hurricane and it becomes too weak near the equator, so hurricanes can never form very close to the equator.
What are the benefits of hurricanes?
The East Coast is lined with barrier islands, from Long Island, near New York City, all the way to Florida. The barrier Islands are made of sand. Over time the wind and waves cause the islands to form, move, and disappear. Homes and communities on the barrier islands often see the most damage from flooding and high winds when a hurricane hits. However, James Pilkey, a Geology Professor at Duke University explained how the barrier islands are positively affected by hurricanes. "Barrier islands need hurricanes for their survival, especially at times of rising sea levels such as now. It's during hurricanes that islands get higher and wider," he said. "From a purely natural standpoint hurricanes are a blessing for islands, even though they're a curse for people who live there." (http://today.duke.edu/2004/09/hurricane_tip_0904.html)
There are a few other benefits that come from hurricanes. They bring rainfall to areas. While too much rain can be catastrophic, there are some areas that depend on the rain from hurricanes. For example, Japan gets about half of its rainfall from typhoons. A hurricane churns up cool water from below the surface. This causes cooler surface water and air temperatures.
There are also many birds like the Piping Plover, which benefit from hurricanes. Piping Plover, and other shore birds lay their eggs on big sand beaches. They nest in areas that do not have grass or other vegetation. Hurricanes change the barrier islands and form the large sand beaches that Piping Plovers need to nest. A hurricane is like a forest fire. It causes a lot of destruction, but it also benefits some habitats, like the beaches that many shore birds depend on.
Hurricanes can be horribly destructive and there are many, many negative effects. We would never wish for a hurricane to happen, but we wanted look into some of the positive effects of this natural disaster. Hurricanes are sort of like forest fires. They can cause a lot of destruction, but they are a natural process.
Satellite image of Hurricane Sandy. Photo by NASA
Live updates about Hurricane Sandy from the New York Times: http://www.nytimes.com/interactive/2012/10/28/nyregion/hurricane-sandy.html
Tracking Hurricane Sandy at the National Hurricane Center: http://www.nhc.noaa.gov/blog comments powered by Disqus