The earths inner core : revealed by observational seismology Machine generated contents note: Preface; 1. On the history of inner core discovery; 2. Seismological tools to study the inner core; 3. Inner core surface and its interior; 4. Inner core anisotropy; 5. Inner core rotational dynamics; 6. The limitations the obstacles and the way forward; Appendix A. Transmission reflection coefficients for the flat inner core boundary; Appendix B. The angle between PKIKP waves and the rotation axis of the Earth; Appendix C. P wave velocity in a transversely isotropic inner core; Appendix D. Transdimensional Bayesian inversion; References; Index The inner core is a planet within a planet: a hot sphere with a mass of one hundred quintillion tons of iron and nickel that lies more than 5000 kilometres beneath our feet. It plays a crucial role in driving outer core fluid motion and the geodynamo which generates the Earths magnetic field. This book is the first to provide a comprehensive review of past and contemporary research on the Earths inner core from a seismological perspective. Chapters cover the collection processing and interpretation of seismological data as well as our current knowledge of the structure anisotropy attenuation rotational dynamics and boundary of the inner core. Reviewing the latest research and suggesting new seismological techniques and future avenues it is an essential resource for both seismologists and non seismologists interested in this fascinating field of research. It will also form a useful resource for courses in seismology and deep Earth processes