We know that P1V1 = P2V2, if there is a constant pressure, then the P1 and P2 can cancel out, so it is V1=V2 that is whats left.
I believe it is lithosphere
Newton's new “reflecting telescope” was more powerful than ... Before Newton, scientists primarily adhered to ancient theories on ... laws of motion laid the groundwork for classical mechanics. Newton's research on motion helped give credibility to the heliocentric view. Newton also helped pioneer telescopic innovations, and he is sometimes credited with inventing the first reflecting telescope. He also conducted experiments using the prism, and developed a theory about the nature of color and light.
If it takes 1 year for this crab to travel 5,70km
Then, it will takes approximatly 1000/5,70 = 175 years to travel 1000 km