The goals of NASA’s Terrestrial Planet Finder (TPF) and ESA’s Darwin missions are to find and characterize terrestrial planets in the habitable zones of other stars, and to search for evidence of life in the atmospheres of any planets found. A key issue that must be addressed is the size of the sample of stars that must be searched before the scientific community, the funding agencies, and the ...

The results of numerical modelling show that the mechanical stratification of the crust provides the fundamental control on fault spacing and, ultimately, the mode of extension. Macroscopic pre-existing structures and weaknesses are often thought to govern the behaviour of continental crust under extension, and many prior studies have focussed on the effect of heterogeneities in triggering faul...

JULY 2005, GSA TODAY ABSTRACT The subduction factory processes raw materials such as oceanic sediments and oceanic crust and manufactures magmas and continental crust as products. Aqueous fluids, which are extracted from oceanic raw materials via dehydration reactions during subduction, dissolve particular elements and overprint such elements onto the mantle wedge to generate chemically distinc...

The straightforward but unexpected relationship presented here relates crustal thickness to magma type in the Izu-Ogasawara (Bonin) and Aleutian oceanic arcs. Volcanoes along the southern segment of the Izu-Ogasawara arc and the western Aleutian arc (west of Adak) are underlain by thin crust (10-20 km). In contrast those along the northern segment of the Izu-Ogasawara arc and eastern Aleutian a...

Abstract Understanding the occurrence of Earth-sized planets in habitable zone Sun-like stars is essential to search for Earth analogs. Yet a lack reliable Kepler detections such has forced many estimates be derived from close-in (2 < P orb 100 days) population, whose radii may have evolved differently under effect atmospheric mass-loss mechanisms. In this work, we compute intrinsic rates su...

T h e problem of the origin of the cont inental crust can be resolved into two fundamenta l quest ions: (1) the lo­ cation and mechani sms of init ial m a n t l e extract ion of the primitive crust and (2) the processes by which this primitive crust is converted into the cont inental crust that presently exists . W e know that Archean cont inen­ tal crust is compos i t iona l ly dist inct from ...