I'm no tank expert, but if I were going to pry it off, it exactly where the wedge would go.
Missing in the pictures is a chain ball skirting that is placed all around the turret to trigger RPG's to go off ahead of time. Some of the advantages of design of the Merkav is that the engine is in the front adding a third layer of shell adsorbsion to an anti-tank round. First the shell must penatrate the highly angled front plating, explodes in the engine and behind the engine is the engine compartment firewall armor layer. It is like a free extra layer of armor in the most vunerable spot.
A second feature is the very sharp angle of the turret, where it meets the barrel, it is the same width of the barrel. When the tank is dug in behind a berm or rock all you see from the distance is a barrel hole with no turret sticking up.
The third and fourth advantage's are that since the engine is in front, there is a hatch on the back of the tank for troop access. That allows it to be used as a battlefield ambulance for wounded troops. You can just toss a wounded buddy in the tank to evacuate him. It can also be reloaded while in action on the battle field. The IDF have developed special vehicles to do so. The M1A1 needs to be pulled back to the rear to be reloaded through the top hatches. This keeps tanks on the front lines where you need them, instead of having to recycle them during major attacks.
All in all a very nice tank, with electronic control systems that equal the M1A1 for firing on the roll.
It sure looks that way, but I will bet you that there is something to prevent this in the bottom of that crack. Something they aren't going to tell you about.
Also, it looks to me like the hanging chains visible in picture 3 of post 4 are going to keep RPGs out of that area from behind. when they aren't posing for pictures, they might have something like this in the front too.