23 Foot Wave

San Francisco Chronicle, July, 1998
Tsunamis: the Killer Sea Wave

A 23-foot (7-meter) wave, propelled by a magnitude-7 undersea earthquake, destroyed a stretch of Papua New Guinea's northwestern coast. It is believed that at least 3,000 people died. Hundreds were injured. Others are believed to have fled to higher ground. An estimated 6,000 people are left homeless.

• Tsunamis are generated by massive underwater earthquakes and are common in the Pacific.
• The destructive waves can travel at more than 435 mph.
• The waves move inland from deep ocean to shallow water, growing larger.
• Individual waves may occur at intervals of 15 minutes, or 125 miles apart.
• Approaching a coast, the waves slow down, bunch up and rise, sometimes as high as a 10-story building.
• The breaking waves can cause massive destruction.