Poseidon vs Polaris

In this library book published in 1976 or 1980, I read that the Poseidon missile had over twice the yield of the Polaris. Yet in the same book it said that the Polaris had a 200 kiloton yield. The Poseidon, on the other hand, had only a 50 kiloton yield. What's up? I'm starting to think that someone made a typo on that book and meant to say 20 kiloton yield, which makes sense, but I'm not sure. Anyone with the facts on that?

PS Is the Poseidon still in use, or has it been completely replaced by the Trident?

 

Both of these weapons were the same: non-existent. They didn't show up until well after WWII.

 

Actually technically the Trident itself has been replaced...by Trident III's

Of which every American Ohio class missile sub carries 24, each with up to 7 warhead (including decoys)

Typhoons carry 20 missiles (AFAIK...except Red October which has 26 )

 

That means the Poseidon has been replaced a long time ago? Why? Low yield? Unaccurate?

 

I think this makes sence as it's true...

Early Polaris missiles carried only 1 warhead (later versions carried a max of 3 RV's iirc)...so 1 warhead of 200Kt
Poseidon wich is essentially an upgraded Polaris could carry a max of 10 warheads (MIRV)..so 10 x50Kt...500Kt yield

Why would one replace a missile?
Becuase they developed a bigger, better one with more range, accuracy etc. etc.

http://www.astronautix.com/lvfam/polaris.htm