Tsunami Detection and Causes

What happens to a tsunami wave as it approaches the shoreline where the water depth decreases?

• Its speed increases, and its amplitude decreases.

• Its speed decreases, and its amplitude increases.

• Its speed and amplitude both increase.

• Its speed and amplitude both decrease.

What causes the continuous movement of Earth's tectonic plates?

• The gravitational pull of the Moon.

• The circulation of molten lava in Earth's core.

• The rotation of the Earth on its axis.

• The constant erosion by wind and water.

Where are most earthquake-prone areas found on Earth?

• In the center of continental landmasses.

• Along the boundaries where two tectonic plates meet.

• Deep within the Earth's mantle.

• Only in areas with active volcanoes.

In a subduction zone, what happens when an oceanic plate meets a continental plate?

• The continental plate sinks beneath the oceanic plate because it is denser.

• Both plates move sideways past each other without sinking.

• The oceanic plate sinks beneath the continental plate because it is denser.

• Both plates rise upwards, forming new land.

What type of energy release from a subduction zone is most likely to cause a tsunami?

• Slow, gradual energy release over time.

• No energy release, where energy is stored for centuries.

• Fast energy release in a fraction of a second.

• Energy released through volcanic eruptions.

What causes ocean waves to crash onto the shore?

• The water particles moving forward with the wave.

• The strong winds pushing the water towards the shore.

• The wave amplitude becoming very high due to circumstances near the shore.

• The deep ocean currents pulling the water towards the land.

What is a potential sign that a tsunami might be approaching, even before the main wave arrives?

• The shoreline dramatically receding, exposing the seabed.

• An increase in the number of marine animals on the beach.

• The water becoming unusually calm and still.

• A sudden change in the color of the ocean water.

What was the primary cause of the devastating 2004 Indian Ocean Tsunami?

• A massive volcanic eruption under the sea.

• A large meteorite falling into the ocean.

• A significant underwater landslide near the coast.

• An extremely strong underwater earthquake caused by tectonic plate movement.

Which of the following can cause tsunamis?

• Only underwater earthquakes.

• Only volcanic eruptions and landslides.

• Only large masses falling into the ocean.

• Underwater earthquakes, volcanic eruptions, landslides, and large masses falling into the ocean.

How do modern tsunami early warning systems typically detect tsunamis in the deep ocean?

• They use satellites to directly measure wave height from space.

• Pressure sensors on the ocean floor detect changes in water level and relay data via buoys and satellites.

• They rely on coastal observers to report unusual wave activity.

• They predict tsunamis based on changes in ocean temperature.