1)
What is the meaning of "Tipasach"?
1.
Radak: It is an expression of untying, like "va'Yfatach ha'Gemalim" (Bereishis 24:32). It is as if [Bavel] was tied until now, and now it will be opened to come against Yisrael. The Targum, Tesharei, is like Targum Onkelos there (v'Ashri 1 ). It can also mean opening; this is close to untying.
1
In our texts, it is u'Shra. (PF)
2)
Why did He say that the evil will begin from the north?
1.
Rashi citing Gitin 6a: Bavel is north of Eretz Yisrael.