[OS X TeX] Page break in index

[John Thoo]

Hi, everyone.

I have a second index question.

I have the following index entry:

  \index{Earthquake!magnitude}

which correctly generates in the Index

  Earthquake
        magnitude, 501

The problem is that "Earthquake" appears at the bottom of page 530 (right column) and "magnitude" (the subentry) appears at the top of page 531 (left column).  How can I keep them both together on the same page?

Thanks in advance.

---John.
(I receive the digest)