Natural Disasters: Tornadoes and Tsunamis

Tornadoes

• Ranked on the Fujita Tornado Damage Scale from F0 (weakest) to F5 (strongest).
• F0 tornadoes have wind speeds under 73 mph; F5 tornadoes exceed 261 mph.
• Commonly form in "Tornado Alley" in the U.S. during spring and summer.
• Form when cold, dry air from Canada meets warm, moist air from the Gulf of Mexico, creating rotating funnel clouds.
• Carry harmful debris, which can damage buildings and property.

Tsunamis

• Caused by underwater earthquakes or volcanic eruptions, resulting in series of long waves.
• Initially low in height due to deep ocean water, but can increase significantly as they approach shallow coastal areas.
• Some tsunamis have produced waves over 100 feet high.
• Notable tsunami in 2004 killed over 200,000 in Indonesia, highlighting significant impact on coastal regions.

Floods

• Occur from prolonged heavy rainfall leading water bodies to overflow.
• Can cause destruction to infrastructure like roads, bridges, and homes.
• Floods are categorized as slow or flash floods, with flash floods being extremely dangerous due to rapid onset.

Volcanic Eruptions

• Involve discharge of gases, ash, and molten rock from Earth's crust.
• Eruptions can vary from explosive to gentle.
• Create new landforms as lava cools and solidifies, contributing to Earth's crust.
• Major types of volcanoes include shield, composite, and cinder cone.
• Significant volcanic activity concentrated in the Pacific Ring of Fire, includes Mount Fuji, Mount St. Helens, and Mount Pinatubo.

Earthquakes

• Sudden shaking caused by shifts at tectonic plate boundaries, predominantly in the Pacific Ring of Fire.
• Major risks include building collapses and gas line ruptures, which can ignite fires.
• Measured using seismographs, with magnitude determined by the Richter Scale.
• The largest recorded earthquake occurred in Chile in 1960, rated 9.5 on the Richter Scale.

Wildfires

• Uncontrolled fires that can devastate forests, grasslands, and residential areas.
• Rapid spread due to environmental factors and human activity, including arson.
• Result in loss of wildlife and crops.
• High winds can prolong the fire’s duration and distance traveled.

Droughts

• Result from prolonged lack of rainfall, severely affecting agriculture and ecosystems.
• Cannot be accurately predicted, necessitating water conservation measures.

Landslides

• Involve the downward movement of soil and debris, often triggered by heavy rain or earthquakes.
• Can reshape landscapes and pose risks to populated areas.

Hurricanes

• Rotating tropical storms with winds exceeding 150 mph, rated on the Saffir-Simpson Hurricane Wind Scale from Category 1 to 5.
• Form over warm ocean waters (80°F or warmer) and cause extensive wind damage and flooding upon making landfall.
• Category 1 hurricanes have winds between 74-95 mph; Category 5 hurricanes exceed 157 mph.
• Hurricane Harvey (2017) and Hurricane Katrina (2005) are notably destructive and costly storms in U.S. history.

Natural Disasters

• Catastrophic events caused by natural processes that lead to injury, death, and destruction.
• Can significantly alter Earth's surface and contribute to processes like weathering and erosion.