Hi, I like to taste the finest tea the world has to offer and I found that Starbucks has some of the finest tea around. Last time I went to Seoul, I went into a Starbucks (I think there are several in the city) and bought a brand of tea called "TAZO". Each bag was packaged in paper separately in a box and on the back of the package (for a tea bag), I saw this writing:

After Mt. Mazama erupted 7,700 years ago,  there was a spot in the southern Cascades where you could feel the warmth of the lava and the cool of the jet stream...

Why do they have the definite article "the" in both places before the words "lava" and "jet stream"? I think they are there because they are used to make a general reference to all lava and jet streams with the specificity that is intrinsically based(?).