https://www.nationalgeographic.com/environment/article/tsunamis

During a science class discussion, Maylin asked, 'What primarily causes tsunamis?'

• Undersea earthquakes

• Strong winds

• River floods

• Coastal erosion

Answer explanation

Undersea earthquakes primarily cause tsunamis by displacing large volumes of water and generating powerful waves.

Match the following locations with the correct description of their relevance to tsunamis.

• Most tsunamis occur here due to tectonic activity

• Pacific Ocean's Ring of Fire

• Very rare tsunamis due to minimal tectonic boundaries

• Indian Ocean

• Known for the 2004 tsunami disaster

• Atlantic Ocean

• Less frequent tsunamis, but still possible

• Arctic Ocean

Answer explanation

Most tsunamis occur in the Pacific Ocean's Ring of Fire, making it the correct choice.

Lucy is studying oceanography and learns about the speed of tsunamis. How fast can tsunamis travel across the sea?

• Up to 500 miles per hour

• Up to 100 miles per hour

• Up to 200 miles per hour

• Up to 300 miles per hour

Answer explanation

Tsunamis can travel up to 500 miles per hour across the sea.

Imagine Lucy and Harden are at the beach observing the ocean when a tsunami's trough reaches the shore first. What happens next?

• It recedes quietly without effect

• It causes a loud noise

• It immediately floods the land

• It creates a vacuum effect that pulls sea water back

Answer explanation

When a tsunami's trough reaches the shore first, it creates a vacuum effect that pulls sea water back, leading to a significant water recession before the wave hits.

Imagine Lucy and Harden are at a beach observing the ocean when they notice a tsunami wave train approaching. What exactly is a tsunami wave train?

• A single large wave

• A series of successive waves

• A high tide scenario

• A low tide scenario

Answer explanation

A tsunami wave train is a series of successive waves, not a single large wave, high tide scenario, or low tide scenario.

The best defense against a tsunami is (a)   .

• Early warning systems
• Building strong walls
• Living far from the coast
• Ignoring the warnings

Answer explanation

The best defense against a tsunami is early warning systems as they provide crucial time for evacuation and preparation.

During a science project, Harden, Lucy, and Maylin are discussing what might cause a tsunami besides earthquakes. What do they suggest?

• Heavy rainfall

• Melting icebergs

• River discharge

• Underwater landslides

Answer explanation

Underwater landslides can also cause tsunamis, not just earthquakes. The displacement of water due to underwater landslides can generate powerful waves.

Imagine Lucy and Harden are at the beach observing the ocean. How do tsunami waves behave as they approach shallow waters near them?

• They maintain speed and height

• They speed up and decrease in height

• They disperse and vanish

• They slow down and increase in height

Answer explanation

Tsunami waves slow down and increase in height as they approach shallow waters, causing them to become more destructive.

During a science project, Maylin is researching early warning systems. What does the Pacific Tsunami Warning System do?

• Studies marine life

• Predicts earthquakes

• Controls the ocean currents

• Identifies tsunamis at sea

Answer explanation

The Pacific Tsunami Warning System identifies tsunamis at sea, providing early warnings to coastal areas to mitigate potential damage.

During a science fair, Lucy explained that besides earthquakes, (a)   can also cause tsunamis.

• Moon phases
• Global warming
• Sun flares
• Meteorite impacts

Answer explanation

Meteorite impacts are an unusual source that can also cause tsunamis, making it the correct choice among the options provided.