By mid-May, as the earthquake magnitudes steadily increased, so too did the public's sense of crisis.
The magnitude 1-4 quakes had been barely perceptible, but when the magnitude 5 quake hit, everyone in the cities near the epicenter felt the tremors. Some were even jolted from their sleep.
This made people realize that the uneventful first half of the month was over.
The latter half of the month—the half that truly represented disaster and destruction—had begun.
Just as with the lower-magnitude quakes, the interval between the high-magnitude ones—7, 8, 9, and even the final magnitude 10 great earthquake—was still 72 hours.
How many 72-hour periods would it take to complete the rescue efforts from a single magnitude 8 earthquake?
