Q: How fast does a tsunami travel?
A: In deep water a tsunami moves at a speed of over 600 miles per hour.

Q: How far can a tsunami travel and still cause damage?

A: A tsunami can travel long distances without a significant loss of energy. In 1960, a tsunami started by an undersea earthquake off Chile travelled undetected 6000 miles across the Pacific Ocean, striking Japan 18 hours later with a 20 foot wave that killed 800 people.

The Author’s Science Adviser for Q&A’s:
Dr. Charles Carrigan, Lawrence Livermore National Laboratory.