Tsunamis

• What natural event caused the 2011 Japanese tsunami?

  Earthquake
• What is a tsunami?

  Water displaced from the ocean by tectonic plates
• How long did the earthquake last during the 2011 tsunami?

  6 minutes
• How do tsunamis travel from their epicenter?

  Tsunamis radiate from the epicenter
• At what speed can tsunamis travel?

  500 miles per hour
• What happens to tsunami waves as they approach land?

  They become slower and grow taller
• What is a hazard in the context of tsunamis?

  Risk of damage to people and property
• Why was the Japanese tsunami particularly hazardous?

  Due to a mix of physical and human factors
• What physical factor contributed to the tsunami's hazard related to its distance from the coast?

  Short distance between epicenter and coast
• How did the earthquake's depth affect the tsunami's hazard?

  Shallow earthquake caused strong seafloor shaking
• What was the impact of the earthquake's duration on tsunami waves?

  Allowed many waves to radiate outwards
• What are the physical factors that increased the hazard of the Japanese tsunami?

  • Magnitude of 9.0
  • 6 minutes long
  • 45 miles away from coast
  • 15 miles deep
• What was the height of most sea walls in Japan during the tsunami?

  4 meters high
• How did public trust in existing strategies affect the tsunami's hazard?

  People didn't think the tsunami was a major risk
• How did the earthquake's shallow depth influence the seismic waves?

  Seismic waves traveled short distances through rock
• What demographic factor increased the hazard of the tsunami in Japan?

  Many elderly people unable to evacuate
• What are the definitions of physical and human factors in the context of hazards?

  • Physical factors: Naturally occurring elements like mountains and rivers
  • Human factors: Man-made structures like buildings and roads
• What were the combined effects of physical and human factors on the tsunami's hazard level?

  • Powerful earthquake displaced large volumes of water
  • Short distance to coast allowed waves to strike quickly
  • Inadequate sea walls could not contain the tsunami
  • Public trust in strategies led to delayed evacuations
  • Vulnerable elderly population unable to evacuate in time