compilation of mountains throughout the world shows that a major
phase of uplift occurred in the Pliocene-Pleistocene." "Uplift
occurred over a relatively short and distinct time. Some earth
process switched on and created mountains after a period with little
or no significant uplift. This is a deviation from uniformitarianism."
all major mountain ranges in the world are a consequence of crustal
The presence of mountains on the front and back sides of continents (along their line of travel), the relatively short distances travelled, and the brief burst of mountain building point to a sudden impulse rather than a steady, constant force moving the continents. Important driving forces of plate tectonics theory are too weak to raise mountains.
In Shock Dynamics, the shock wave from the giant meteorite impact provided the impulse that initiated continental motion. Some continents began moving after being hit by a continent already set in motion by the impact. Assuming the acoustic fluidization mechanism, and assuming that mountains are built through lateral compression, the minor mountains (such as the Appalachian Mountains) raised by the impulse against a continent's back side indicate a comparatively slow acceleration. The major mountains (such as the Rocky Mountains) raised on the front, or leading, side indicate a sudden deceleration, like a multi-car pile-up on a highway. This braking effect all along the leading edge suggests that acoustic energy was lost most rapidly there, probably through thinning the overlying mass confining the acoustic energy. Most other mountains were laterally compressed by means of collision with other continents or by torque.
North and South America stopped suddenly because their western sides grabbed the lithosphere below them. These huge landmasses transferred their momentum to the lithosphere, Earth's outer shell.
So with a jolt, Earth's outer shell, the lithosphere, suddenly slowed its eastward rotation relative to the shell below it, the upper mantle. We can see this displacement by comparing two scars in the Earth from the giant impact; one shallow, one deep.
In the Shock Dynamics interpretation, they were both made by the same meteorite impact, but the depression in the upper mantle (above right) rotated past the focus of inelastic lithosphere (above left).
continued thereafter and still does, but at a creeping pace of 5
to 13 cm per year.
In the differential rotation model, the lithosphere and outer
core show a net westward drift, while the mantle and inner core
Both features are unique on the Earth, as you can see from the global maps below.
The Earth flexes as the
Moon revolves around it. The place where it is the least flexible
is shown in dark blue above, next to Africa. This solid Earth (body) tide
projection was "generated from the actual history of the tidal
forcing". It is a measure of elasticity.
And the only deep geoid/gravity anomaly low on Earth is shown in dark blue below, next to India:
From: The Gravity Field and Steady-State Ocean Circulation
Explorer (Goce) global geoid map, 2010,
From: Sreejith, K.M., S. Rajesh, T.J. Majumdar, G. Srinivasa
Rao, M. Radhakrishna, K.S. Krishna, A.S. Rajawat.
"The existence of the Indian Ocean geoid low (IOGL) is one of the most outstanding problems in Earth Sciences," said Attreyee Ghosh, an assistant professor at the Centre for Earth Sciences, Indian Institute of Science, in Bangalore, India. "It is the lowest geoid/gravity anomaly on Earth and so far no consensus exists regarding its source. It is remarkable as it means that there is some mass deficit in the deep mantle that's causing the low."
"To 'look' deep inside the Earth, they used seismic tomography models that use seismic waves to obtain a 3-dimensional picture of the Earth's interior. The study showed that lighter material (low density anomalies) in the upper to mid mantle below the IOGL seem to be responsible for the existence of the gravity low in this region."
" 'Our study explains this low with hotter, lighter material stretching from a depth of 300 km, or 186 miles, up to ~900 km, or 559 miles, in the northern Indian Ocean' ".
See interview at: https://phys.org/news/2017-10-masswhat-geoid-indian-ocean.html
Two cross-sections (A - A' and C - C') of the IOGL are shown below the transect map. They derive from the GyPSuM_S seismic tomography model. Notice that the hot material is not the top of a plume but is isolated below the lithosphere at about 500 km (310 mi) depth.
From: Ghosh, Attreyee, G. Thyagarajulu, Bernhard Steinberger. 2017. The Importance of Upper Mantle Heterogeneity in Generating the Indian Ocean Geoid Low. Geophysical Research Letters, Vol. 44, pp. 9707-9715 DOI:10.1002/2017GL075392