Please give an explanation of these lines from "Ode to the West Wind."Thou who didst waken from his summer dreams The blue Mediterranean, where he...

You have quoted the third stanza from this terrific poem
in its entirety. Of course, there is always a danger of just looking at specific parts
of a poem separately and not in the context of the poem as a whole, so when you have
finished reading my response I suggest you go back and see how this stanza fits in to
the poem as a whole.

This stanza begins with the poet
addressing the West Wind (what is known as an apostrophe), and talking about the wind's
impact on the sea. The wind is shown to stir up massive waves, disturbing the ocean as
if it was waking somebody from a dream. The Mediterranean is pictured as a man asleep
who is woken up by the wind's power. A much more violent picture of the wind is
presented later on in the stanza, especially when the wind's impact on the Atlantic is
described. The "Atlantic's level powers / Cleave themselves into chasms" in response to
the wind, and its power is so great that even the "sea-blooms and the oozy woods" of the
ocean "suddenly grow grey with fear" when they hear the wind coming. This stanza
therefore serves to reinforce the power and majesty of the wind by focusing on how it
impacts the sea.