How to understand it?
A spur of the Gulf Stream and part of Japan Current…
Here, what does "a spur of" mean?

Question

How to understand it?
A spur of the Gulf Stream and part of Japan Current…
Here, what does "a spur of" mean?

Answer

A "spur" means a branching off of. So the water is moving like this:  --------------------------------
                                                                 _______
and then in a spur, it goes like this: -----