The Earth's deep interior: advances in theory and experiment

摘要: The Earth extends some 6400 km to the centre where conditions of pressure ( P ) and temperature T reach over three million times atmospheric ca .6000°C. We stand on thin brittle crustal plates moving through geological time a continuously deforming mantle slowly convecting hot rock. about halfway liquid outer core solid inner core. Although make up 99% by volume mass, we are only able sample material directly few hundred kilometres, from inclusions in diamonds that brought surface volcanic intrusions; remaining 90% is effectively inaccessible. most direct knowledge have Earth9s deep interior comes seismic waves generated earthquakes. A properties coupled with these tell us made complex silicates predominantly iron alloying elements. However, detailed structure poorly constrained. Major advances toward understanding composition, dynamics be gained combination experimental theoretical techniques. It already clear many large–scale processes responsible for at driven there questions yet answered exact nature mantle, interaction between them. For example, fully define major– minor–element chemistry convective regime elements core, core–mantle boundary dynamical governing geodynamo. Advances high– / techniques last two decades allow laboratory simulation physical shedding light physics interior. High can maintained significant periods (minutes days) multi–anvil diamond–anvil presses. Shock experiments produce high megabar range tiny durations (milliseconds), but, doing so, they shed current development situ high–pressure research such as P– S–wave interferometry, electrical conductivity synchrotron–based X–ray will, coming decades, improvements our Earth. Even increasing depth, it becomes increasingly difficult mimic extreme precisely. An alternative use computer simulations, which test models best match evidence data. In particular, powerful supercomputer resources, emphasis now being placed ab initio quantum–mechanical calculations simulate materials found This approach allows predict candidate remarkable accuracy when compared data results experiments. With techniques, also trying solve problems out experimentation involving simultaneously , alloys under squeezed half its normal volume, will soon provide constraints profile Earth, which, depths, known within thousand degrees! therefore challenge next years among deep–Earth scientists develop accurate measurements conditions. an interdisciplinary theory, experiment seismology determine nature, evolution influence