Berkeley, Wednesday, March 25, 2020 1:54 AM
We live on a wonderful active and dynamic planet. Even things that are harder to sense of their dynamics, but many were able to first capture and as we have developed metrics and monitoring we can actually explain those process.
Mountains grow and decrease. They move, as continents move as well. If there is that large sediment contribution to the Yellow River (and other four rivers in the area) from the Himalayas, why the Himalayas mountain range does not decrease, yet. Well, there is an active continental collision between India and Asia (or Eurasia). The Indian Plate is subduing under the Eurasian plate. I am not sure about the actual time when the collision started. I need to go and check that.
Other mountains that has passed that growing process and rather has a decreasing elevation or relief are Appalachian mountain range. But why there are mountains and not everything is eroded, as our eye or time can more easily capture transport of pebbles, boulder and sand in the streams and rivers? One of the answers is isostasy. Another fascinating fact is that we are floating. We live on a tiny layer called lithosphere if we compere it on thickness to the asthenosphere on which we are floating.
Then, why are there volcanos, why do they erupt? On what depends their crater size? Why there are rivers? Well the questions are not necessarily why, but how, and I might briefly write here about those processes in other time.
A question that I have not even think about, and I do not know if there is an answer out there is why the Earth has it current size? So far we know that the Earth has a radius of 6,371 km. I do not know if we know why? Perhaps are the right questions to ask how instead of why?