Natural events happen without humans causing them. Examples: rainbow, rain, volcanic eruptions, hurricanes, earthquakes.

Types of Natural Events

Atmospheric Events

Happen in the air. Studied by meteorology.
Rain – Water vapor turns into clouds. Heat makes clouds rise and cool. Drops get bigger and heavier, then fall.
Wind – Air moves due to pressure differences.

Hydrological Events

Linked to water. Studied by hydrology.
Ocean currents – Water moves in oceans.
Waves – Wind pushes on ocean/water surfaces.

Biological Events

Related to living things and their interactions.
Migration – Animals move from one place to another.
Extinction – A species disappears completely.

Geological Events

Linked to Earth’s solid parts. Studied by geology.
Orogenesis – Earth’s crust bends, shortens, thickens from tectonic forces.
Oil formation – Organic material builds up over millions of years. Pressure and heat turn it into oil.

More Examples

• Thunderstorms
• Rain
• Hail
• Earthquakes
• Tsunamis
• Snowstorms
• Winds
• Cyclones
• Hurricanes
• Volcanic eruptions
• Stalactite formation
• Water salinity in lakes
• Flower blooming
• Fish egg-laying
• Monarch butterfly migration (USA/Canada to Mexico)
• Northern lights at poles
• Forest fires
• Avalanches
• Tornadoes
• Insect metamorphosis or skin shedding

How Do They Affect Us?

Natural events can help or harm people, animals, and Earth.

Rain helps crops grow – good.
Hurricanes cause damage and harm – bad.

Natural Disasters

These are harmful natural events.

Human actions can make disasters worse. Example: a dam breaks, releases all water, floods and destroys everything in its path.

Examples of Disasters

• Haiti earthquake (2010)
• Japan quake & tsunami (2011)
• Hurricane Katrina (2005) – ruined coastal cities along Mississippi River; almost destroyed New Orleans, USA
• Vesuvius eruption (ancient Rome) – buried Pompeii in ruins