In their recent Science paper (reprint), S. Merkel, A. Kubo, L. Miyagi, S. Speziale, T. Duffy, H.-k. Mao, and Rudy Wenk investigate the deformation behavior of germanate post-perovskite at pressures beyond 100 GPa. From the pattern of preferred orientation they determine that slip (100) and (110) slip is dominant. With this experimental information they model seismic anisotropy at the core-mantle boundary and suggest that perovskite contributes about 4% to shear wave splitting in D", with an oblique polarization.
In their paper recently published in Nature (reprint) Bill Dietrich and Taylor Perron investigate the influence of biota on the processes controlling landscape form and evolution. They find that while the signatures of life are present at all scales, there is no single landform that uniquely reflects the presence of life. Listen to the Nature Podcast (segment starts at 16:30).
In a paper recently published in Nature (reprint) Erik Olson and Richard Allen report a scaling relation between the frequency content of the first few seconds of energy radiated from an earthquake rupture and its magnitude. These characteristics can be used to estimate the magnitude before the rupture is complete and provide a basis for an earthquake alarm system.
In a paper recently published in Science, graduate student Aimin Cao, Professor Barbara Romanowicz and collaborator Nozumu Takeuchi report on the to-date most clear detection and identification of PKJKP, the elusive seismic phase that travels as a shear wave through the inner core.