They typically update these if/when more information becomes available. Links there to maps, technical info, etc, and they like it if people who felt the thing report what they felt at "Did you feel it -- Tell Us" link.
A lot of us Californians have the USGS Earthquake map page right near the top of our "Bookmarks"
Last week there were two minor quakes along the New Madrid also. So maybe these lil tremors will let off pressure. Praying that baby don't let loose. Last time it rolled the MS river flowed backwards in a spot for 3 days... Scary, especially with all the development in the zone.