As a 5.3 earthquake rocked the greater Los Angeles area Sunday afternoon, it took just a few minutes for the region’s television stations to jump in with live reports from some unlikely reporters.KABC was the first on the air, with weatherman Rick DeReyes anchoring from the newsroom. With little information at hand, DeReyes estimated the quake to be in the 5 .0 Richter range. He also reported minimal damage to homes in several outlying areas. On KNBC, the second station to post a live newsroom shot, sportscaster Bret Lewis offered reports from regional sites that had suffered varying but mostly limited amounts of damage. The station also was the first to send a crew outside a half-hour later, to get public reaction. At KCAL, entertainment reporter John Corcoran went on the air simply to announce the quake. Independent station KTTV (Fox), airing the feature film “Sophie’s Choice,” and KCBS, tied up with the NCAA basketball tournament, weighed in with dispatches a few minutes later.