Blank database entries

Any time a user edits their profile without changing any of the location fields, a semi-blank row is created in the location table of the database. The EID, LID, and TYPE columns are written to, but the rest of the columns remain blank. This is not a very efficient way of handling this and I'm sure that on high traffic sites this could unnecessarily fill the database with useless entries.

Any ideas on how to alleviate this issue?