I see this pulp magazine cover all the time and I didn't really pay attention to it until this morning, ignoring it as just another entry to generic pulp magazine art.
The cover art for the July 1929 Amazing Stories sort of depicts a scene from the Jules Verne story "The Desert of Ice". Then I took a closer look at the painting.
I'm sorry, but that image is hilarious. None of the bears hurtling skyward seem overly upset over being at the epicenter of a huge detonation of black powder. Two of the bears are tossed up in mid-step (one is upside-down) and are quite nonchalant, another is sniffing around for the abruptly missing ground and another is looking about curiously as if puzzled about the sudden over-abundance of flame. Only one polar bear is hightailing it away from the scene. For all the action they display they could be colorforms of bears stuck on a canvas.
While this cover disconnect isn't as radical as some of the entries from pulps and comic books it does resemble more the illustration and description featuring the active Arctic volcano expelling lava and rocks than the disposal of troublesome, hungry polar bears.
The cover art is kind of an interesting creative mix of the two ideas, probably derived from whatever art instructions or notes were given to the artists.