Catastrophic Events PDF - Reading Science

Catastrophic Events (B) Earth and Space Catastrophic Events 1 The surface of Earth is always changing. The changes can slowly happen over time, or can happen quickly, without warning. These rapid changes can be devastating to an ecosystem. Tornadoes, hurricanes, and floods are all examples of catast...

Catastrophic Events (B) Earth and Space Catastrophic Events 1 The surface of Earth is always changing. The changes can slowly happen over time, or can happen quickly, without warning. These rapid changes can be devastating to an ecosystem. Tornadoes, hurricanes, and floods are all examples of catastrophic weather events that cause rapid changes. 2 Spring brings warm, moist air that makes new life bloom and grow. Unfortunately, these are the same conditions that can form a deadly tornado. A tornado can form as part of a powerful thunderstorm when warm, moist air becomes trapped under a layer of cold, stable air. The violently rotating column of air reaches from the base of the thunderstorm down to the ground. A tornado acts like a giant vacuum cleaner. It will damage everything in its path. Wind speeds can be as high as 300 miles per hour. These devastating tornadoes can uproot trees, kill animals, and cause catastrophic damage to buildings. Nothing in the path of a tornado is safe. The damage done to an ecosystem by a tornado can take a very long time to repair. 3 Hurricanes also affect an ecosystem in a variety of ways. Hurricanes are very large and violent tropical storms. They develop over warm ocean water. When these storms move onshore, they cause high winds, tornadoes, heavy rains, and floods. In an aquatic ecosystem, saltwater can flood into areas of freshwater, such as lakes and streams, and kill large numbers of fish. The flood water may also contain pollutants that can kill animals. In a terrestrial ecosystem, strong winds, tornadoes, and floods can destroy trees, plants, and animals. Barrier islands protect the coast. During hurricanes, these islands experience large amounts of erosion. Barrier islands can be shifted or completely eroded away. On land or in water, the impact of hurricanes can be devastating. 4 Heavy downpours of rain or sudden melting of large amounts of snow can saturate the land. The ecosystem cannot absorb the water fast enough. Rivers and streams overflow. Flat areas of land, canyons, and valleys experience flash floods. Like tornadoes and hurricanes, floods also have a devastating impact on the ecosystem. Plants and animals can be washed away by powerful, fast-moving water. Pollutants can be mixed in with the flood water, poisoning habitats. Mud carried by fast-moving flood waters can later form thick layers over plants and animals. Fish and other aquatic animals can be swept out of their habitats. They will not find their way back when the flood waters recede. The impact of a flood on an ecosystem can be devastating. 1 Catastrophic Events (B) Earth and Space 5 Catastrophic events, such as tornadoes, hurricanes, and floods, can completely devastate an ecosystem. These events can kill plants and animals or force them out of their homes. These events are a natural occurrence in the ecosystem. The damage that they cause, however, can have a lasting impact for many years. 2