2 adverbs to describe how to debouched

through a flat and arid country, till, after a course of 1100 m., it unites with the Euphrates to form the Shat-el-Arab, which debouches into the Persian Gulf 90 m. lower; is navigable for 500 m. to Bagdad; on its banks are the ruins of Nineveh, Seleucia, and Ctesiphon.

And then he debouched unexpectedly on to the Embankment.

2 adverbs to describe how to  debouched  - Adverbs for  debouched