The detonations must've opened a source deep in the island.

3 seconds sound clip from the Attack of the Crab Monsters (1957) movie soundboard.

You can hear this line at 00:53:50.193 in the DVD version of the movie.

Quote context

[...]

- Ended up in the south pacific?

- Yeah. How'd you get here?

- Well, after Dale and I graduated, we stayed on at the Institute in research.

- You've been together ever since?

- Un-huh.

- And when his promotion comes through, we'll be making it a lifetime partnership.

- Yeah. Well, let's go find Karl and Dale and tell them this thing works.

- All right.

- Is that not oil?

- Yes it is, Karl.

- I've never heard of oil being found on the Pacific islands before.

- The detonations must've opened a source deep in the island.

- But look, it seems to be coming from two sources.

- I suggest we trace them.

- You want to follow this oil underground?

- I feel we must.

- But the crab, Karl.

- The crab is like a rattlesnake. It can be heard long before it can be seen. We can keep out of its way if we remain alert. He knows this better than we do. That is why he is trying to reduce this island to a small corner from which we cannot escape.

[...]