Santa Cruz Aftershocks

Large earthquakes will often be followed by many aftershocks. The one near the Solomon Islands yesterday has had a number. The map below illustrates it excellently:

A number of the aftershocks have been greater than 5 on the richter scale.

A couple of questions that might guide your thinking:
Why might aftershocks still cause much damage though they are smaller than the original earthquake? Can people prepare for aftershocks?

Click on the map above to go to its live site hosted by the USGS, or click below to see another aftershock map of the area from earthquaketrack.com HERE.