Natural Disasters PDF

Natural Disasters No matter where you live, it is likely that you have experienced a natural disaster at some point in your life. Natural disasters are catastrophic events caused by nature. They can be extremely hazardous and can cause major damage to communities and i...

Natural Disasters No matter where you live, it is likely that you have experienced a natural disaster at some point in your life. Natural disasters are catastrophic events caused by nature. They can be extremely hazardous and can cause major damage to communities and injury or death to living organisms. Natural disasters also cause changes to Earth’s surface and play a major role in weathering, erosion, and deposition. There are numerous natural disasters that occur on Earth and nine of the most common and impactful are described in this article. Hurricanes are large, rotating storms that form in the ocean with swirling winds that can reach over 150 miles per hour. They are ranked on the Saffir-Simpson Hurricane Wind Scale from Category 1 to Category 5 based on their wind speed. Category 1 hurricanes are the weakest and have wind speeds of 74 – 95 miles per hour. Category 5 hurricanes are the strongest and have wind speeds of 157 miles per hour or higher. Hurricanes form and intensify in strength over warm ocean water of 80 degrees Fahrenheit or warmer. They cause severe wind damage and extreme flooding as they make landfall along coastal regions. Hurricane Harvey (2017) and Hurricane Katrina (2005) are the two most expensive and damaging hurricanes in the history of the United States. Tornadoes are spinning columns of air with wind speeds that ca reach over 300 miles per hour. Tornadoes in the United States commonly form in an area referred to as “Tornado Alley” in the spring and summer. This area forms tornadoes when dry, cold air moving south from Canada meets warm, moist air traveling north from the Gulf of Mexico. When the two air masses meet, their different speeds create a rotating funnel cloud. One of the most hazardous aspects of tornadoes is the debris that they carry. Debris is the remains of anything broken or destroyed. Debris traveling with tornadoes can cause major damage to buildings, homes, and other property. Tornadoes are ranked on the Fujita Tornado Damage Scale from F0 to F5 based on their wind speed. F0 tornadoes are the weakest and have wind speeds of less than 73 miles per hour. F5 tornadoes are the strongest and have wind speeds of 261 miles per hour or higher. Tsunamis are a series of long waves of water caused by an underwater earthquake or volcanic eruption. Due to the deep ocean water, these waves are not terribly high at first, but they move very quickly. As the fast moving waves travel toward land, their height increases as the ocean water becomes more shallow. Although most tsunami waves are only a few feet high, some tsunamis have been known to generate a wall of water over 100 feet high. Tsunamis cause major damage and death along coastal regions due to the crushing force of the fast moving water. In 2004, a tsunami triggered by an earthquake in the Indian Ocean killed more than 200,000 people in Indonesia. Floods occur when days of heavy rainfall cause rivers, streams, lakes, and other bodies of water to rise over their banks. Floods cause major damage to bridges, roads, cars, homes, buildings, and other structures and can even carry them away in the water. Floods are also very destructive by causing high levels of erosion from the large amounts of water. Some floods occur slowly and can take days or months to build up and then recede. Flash floods are extremely dangerous because they occur very quickly and without warning. © the science duo Volcanic eruptions are the discharge of gas, ash, molten rock, and other materials from a vent or opening in the Earth’s crust. Some eruptions are extremely sudden and violent while others remain quiet and slow. Although volcanic eruptions can cause damage and death, they also help to build up the surface of the Earth. Volcanic eruptions allow magma to rise to the surface. As the lava cools, it forms new crust. The three major types of volcanoes are shield, composite, and cinder cone. Volcanoes are often located at plate boundaries and a large amount of Earth’s volcanic activity is located in the Pacific in an area known as the Ring of Fire. Mount Fiji (Japan), Mount St. Helens (United States), and Mount Pinatubo (Philippines) are examples of some of Earth’s major volcanoes within the Pacific Ring of Fire. Earthquakes are a sudden and violent shaking of the ground that occur at faults, often at plate boundaries. Nearly 80% of all earthquakes occur along the Pacific Ring of Fire. Earthquakes cause damage and death when buildings and other structures collapse or gas lines rupture which also causes fires. Scientists are able to use a tool called a seismograph to measure and record the strength, location, and other details of earthquakes. The Richter Scale is a mathematical rating system that uses information from a seismograph to calculate the magnitude of an earthquake. The world’s largest recorded earthquake occurred in Chile in 1960 and was rated a 9.5 magnitude on the Richter Scale. Wildfires are large, uncontrolled fires that spread quickly and destroy forests, grasslands, and other woodland areas. Unfortunately, homes and other community buildings in the fire’s path may also be destroyed. Due to the fact that they spread so quickly, wildfires cause death to large numbers of wildlife and crops as well. Lightning strikes, human impact (arson and carelessness), and volcanic eruptions are the top factors that cause wildfires. High winds can carry these fires over large distances causing them to last for days or even months. Droughts are caused by a severe and abnormal lack of rainfall in an area over a certain time period. Animals, crops, and other plant life are negatively impacted by severe droughts. Since they are not able to be accurately predicted by scientists, it is important to conserve water in case of a drought. Landslides are the downward movement of soil, rock, or debris down a slope, such as a mountain or hill. Landslides carrying debris can flow 30 – 50 miles per hour and can destroy roads, homes, and other structures in its path. Landslides are often triggered by earthquakes, volcanic eruptions, heavy rainfall, erosion, and human activities. As you have read, there are numerous natural disasters that occur on Earth and cause changes to its surface. By studying natural disasters, scientists are now better able to understand and predict their occurrences. Along with these predictions, there have also been major advancements in technology which have helped save lives by building safer structures and homes. Although it is impossible to stop natural disasters from occurring, having knowledge and understanding of their impact is very beneficial. © the science duo