This question stems from pure idle curiosity. It seems to me that British newsreaders use a special accent, especially when reading out the headlines or introducing a particularly serious story. Perhaps it would be more properly termed a tone of voice rather than an accent, but in either case I've never known anyone to speak in that way in any other situation.
I'm not referring to recieved pronunciaton, but to something much more specific that seems to be only used for news and not other announcements. Similarly, I'm not referring to the mid-Atlantic accent, which also seems to be mostly associated with news readers but is no longer in use. The voice/accent I'm referring to combines a kind of exaggerated seriousness with perhaps a lower pitch of voice than usual. It's difficult to describe but anyone who lives in the UK should be familiar with it. Does it have a name?
Edit: an exaggerated example can be found in this classic parody clip from The Day Today. Most of the characters use their normal voices at first, but once the situation changes around 2 minutes in, all the broadcasters start using the special "serious" voice that I'm asking about.