Anderson and his research team have also used seismic data to study convection currents in the mantle, decisive for understanding continental drift and volcanism on Earth. Recently, Anderson has also used geochemical and chemical-isotope methods for mapping not only Earth s development. These studies are also of importance for the understanding of the development of the Moon and the planets Mars and Venus. The speed and nature of seismic waves give important information on temperature and mineral density. Adam M. Dziewonski is a pioneer in our understanding the properties of seismic waves and how they are propagated through the Earth.
Seismic waves crossing the core change direction - are anisotropic.
Recently the team observed that the inner core is rotating 2-3 degrees faster than the surface. Current research may well show whether this is caused by the processes that may perhaps also explain earth magnetism. Seismic tomography employs differences in the seismic velocity of waves propagating themselves through rock types of different temperatures. Pieces of the puzzle are being added to our knowledge of the Earth s global geochemical cycle. He was Director of the Seismological Laboratory of the California Institute of Technology from 1967-1989.