Lunar forces may be causing the surface of the earth to slip westward, according to a study by Italian and American scientists, which has been published by the Bulletin of the Geological Society of America. Carlo Doglioni of Rome's La Sapienza University and his team of Italian and US scientists argue that the westward motion is due to the tidal attraction of the moon.
The earth's crust is divided into vast plates that slowly shift, producing earthquakes, mountains and rifts where they collide or separate. Most earth scientists believe that this movement is the result of rising and falling currents of magma deep below the surface.
The new research, however, says that in addition to being jostled every which way from below, the planet's plates are slowly sliding westwards. As the earth spins eastward beneath the moon, the moon's gravity ever so slightly holds the earth's surface layer back.
Doglioni points to a profound asymmetry in the distribution of the earth's big mountains as a part of the evidence. Both the Rocky and Andes mountains are on the eastern side of the Pacific Ocean. The answer, according to him, is that in the eastern Americas, the underground forces of plate tectonics are driving the Pacific plates eastward, towards the continental block, which is being pulled westward by the moon's gravity.
On the other side of the Pacific Ocean, the mountain-building force is weaker, because the Pacific plate there is also moving westward, essentially rear-ending the Asian continent. Other scientists reserve their judgment on the study.