The cable news channels started covering the earthquake in Japan shortly after 1 AM this morning, and preliminary overnight numbers are in from Nielsen. Full numbers won’t be in until Monday (or possibly Sunday), but the early results show that the normally quiet overnight shift drew strong numbers for CNN and Fox News.

From 1:14-2 AM, FNC averaged 605,000 total viewers and 271,000 demo viewers

From 1:12-2 AM, CNN averaged 505,000 total viewers and 234,000 demo viewers

From 1:44-2 AM, MSNBC averaged 325,000 total viewers and 118,000 demo viewers

From 2-3 AM, CNN took over the top spot:

CNN: 976,000 total viewers, 449,000 demo viewers

Fox News: 722,000 total viewers, 308,000 demo viewers

MSNBC: 394,000 total viewers, 160,000 demo viewers