Why Did Sokolov Resign against Karjakin Today?

I've been through the game (http://www.tatasteelchess.com/tournament/livegames), but I cannot understand why Sokolov resigned so early.  Can someone help me understand what I am missing?  Looks like Tata has been a disaster for Sokolov!

his queen is trapped!

Because if black moves the g6 knight, Qxg7 is mate, and if he doesn't, white's next move will be Bc2, trapping and winning the black queen, who has no escape route.

The only other choice is ..Be7, which still doesn't help after white's Bf2, taking away the h4 square, and black's queen still can't get out.

well not 100% trapped but I think hell lose a minor piece if he wants to get out. I dont see immediatly how though.

Queen isn't 100% trapped (that I can see -- but I may be missing something), but I agree he's going to lose that bishop on h4 or the knight on g6.  Just seemed a little premature for a resignation.  

So if Im right there are two variations in which he loses a minor piece for a pawn..

I suppose he can lose just a minor, but without compensation, against a 2700+, what's the difference? 

I just saw on the livegames page, below the board there's a computer analysis, (if analysis is on) showing Sokolov behind by 5.37 pawns, minimum. Black has 2 ways to lose only a minor piece, but then he's hammered for it too. Mouse-over the moves to see a board.

ElKitch,

After 33. ...Ne7 in your analysis, white just plays exf6 (threatening Qxg7#), Qf7 fxe7 and black is completely lost.

Sokolov saw the writing on the wall and decided to call it a day.

that line is there too, Kingseye!

Lucidish must be right right -- I just don't have a big enough brain to work it all out.  I thought for a minute that he could have gotten away with a queen sac if he just moved Be7.   After White's Bf2, black goes to g4 and forces the sac or takes away the mate on the g file.  If white moves the queen to e4, black goes to h3, and I think he gets away, right?

...but I'm still assuming I'm missing something because Sokolov wouldn't have resigned if I were right.

Got it.  I see it now.  Thanks Kingseye, ElKitch, and Licidish.

I was also surprised why he gave up 'so soon'. But I know he fights till the end, so it must have been hopeless. This is another possible reason why Sokolov might have given up.

nice one, Loek! better than my variations.

Thanks, Elkitch.

In my pgn there is by accident a bishop on c8. It is not in the game.

Another variant in your more elaborate analysis is possible on move 33.

After 33. Bd1 Qh4 34. Qg6: will black lose two pieces. The bishop can not move because of mate and the undefended rook on b6.