Plate Tectonics

The book I read to research this post was Plate Tectonics A Very Short Introduction by Peter Molnar which is a very good book that I bought from kindle. This book is around 150 pages so is a reasonable length. It is also part of a series where an expert writes a bit of an introduction to a subject and these are pretty informative and written to a high standard. The idea behind plate tectonics is the surface of the planet is quite literally plates floating on hot magma where in general it has cooled near the surface. In the case of the North Atlantic Ridge some of this magma still seeps resulting in earthquakes, and volcanoes and the distance from America to Europe gradually being extended. All this was discovered in the 60’s and in its own way was as exciting a discovery as the lunar landings. Also it has been shown the poles of the Earth swap over from time to time. If this did happen it would cause mayhem and many people would die from the weather extremities induced. We are roughly due for it to happen again. It does have a random element so it is difficult to predict exactly when it will happen. Even though in places the Earth is expanding it other places like in and around Chile it is shrinking and the size of the Earth overall is kept more or less constant. The Andes mountains were formed by the upheaval of these 2 tectonic plates colliding. Also where there are mountains the plates are often a lot thicker a lot more than we’d expect with a lot of this being below sealevel. Where there is ocean the plates are different and much thinner than that which makes up land. The author compares this to icebergs where over 90 % of the mass is often under water. I did very much enjoy reading this book and do recommend it.