Geology ReportsSearch

Geology topics

Raymond Jeanloz

Publications and source records attributed to Raymond Jeanloz.

3 recordsLinked to original sources

Plan for living on a restless planet sets NASA's solid Earth agenda

What are the most important challenges facing solid Earth science today and over the next two decades? And what is the best approach for NASA, in partnership with other agencies, to address those challenges? A new report, Living on a Restless Planet, provides a blueprint for answering these questions. The top priority for a new spacecraft mission in the area of solid Earth science over the next 5 years, according to this report, is a satellite dedicated to Interferometric Synthetic Aperture Radar (InSAR). At the request of NASA, the Solid Earth Science Working Group (SESWG) developed a strategy for the highest priority objectives in solid Earth science for the space agency over the next 25 years. The strategy addresses six challenges that are of fundamental scientific importance, have strong implications for society, and are amenable to substantial progress through a concerted series of scientific observations from space.

Eos Science News

Antiferromagnetism in pressure-amorphized Fe2SiO4

Amorphous Fe 2 SiO 4 synthesized at elevated pressures exhibits a Néel transition at a temperature identical to that observed in the crystalline form, T N = 65 (±2) kelvin at zero pressure. This behavior contrasts sharply with observations on other disordered systems, such as spin glasses, which characteristically exhibit strong "frustration" of the spins and consequent marked suppression of the Néel transition.

Science

Shock-produced olivine glass: First observation

Transmission electron microscope (TEM) observations of an experimentally shock-deformed single crystal of natural peridot, (Mg 0.88 Fe 0.12 ) 2 SiO 4 , recovered from peak pressures of about 56 × 10 9 pascals revealed the presence of amorphous zones located within crystalline regions with a high density of tangled dislocations. This is the first reported observation of olivine glass. The shocked sample exhibits a wide variation in the degree of shock deformation on a small scale, and the glass appears to be intimately associated with the highest density of dislocations. This study suggests that olivine glass may be formed as a result of shock at pressures above about 50 to 55 × 10 9 pascals and that further TEM observations of naturally shocked olivines may demonstrate the presence of glass.

Science