According to expert on CNN, it is from the same area as the 9.0 quake and at 7.1 is considered an aftershock. Aftershocks can go on for 6 months or more.
Or another foreshock - it didn't get much publicity, but there was a 7.2 quake that occurred 2 days before the 9.0, at the same depth (19.9 miles - and it DID appear to create a tsunami) and about 20 miles from the epicenter.
I pray this is not the same type of situation.