What is indicated by the slope of an acceleration vs. time graph?

A slip is going up or down and a time graph is it keep take

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.

Ansa new gas is observed in the form of bubbles;