Geobulletin alpha

Dinosaurs Lost, Mammals Won - How? 

Dinosaurs Lost, Mammals Won - How?  We all know that at the end of the Cretaceous dinosaurs became extinct and that mammals inherited the Earth. We know much about the extinction, less about the success of the mammals.  A correspondent has sent me THIS LINK which tries to answer this question.  Mammals had been around for as long as the dinosaurs but they led very inconspicuous lives and this may have saved them from catastrophe. Many mammalian species became extinct; the ones that [...]

Mapping the Interior of the Earth 

Mapping the Interior of the Earth  A correspondent has sent me THIS LINK. The article is based on THIS PAPER. The original authors have used seismic shear waves that diffract along the core mantle boundary to identify what they call "Ultra-Low Velocity Zones" (ULVZ); in addition they say that they can detect variability within the ULVZ.  These ULVZ are only a few tens of kilometres high, and, being on the core mantle boundary, are very difficult to study. But high frequency waves allow [...]