Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 22 October 1999:
Vol. 286. no. 5440, p. 641
DOI: 10.1126/science.286.5440.641n
Prev | Table of Contents | Next

This Week in Science

Mid-ocean ridges are linear structures where sea-floor spreading occurs by the passive upwelling of melt to form new oceanic crust that then cools and is pulled away from the ridge by subduction at the other end of the spreading plates. The dynamics of the melt upwelling is poorly understood because it is difficult to determine the structure of the magma reservoirs at mid-ocean ridges. Evans et al. (p. 752) have measured the electrical resistivity of the East Pacific rise at 17ºS. They found low resistivities to the west of the ridge, which would be consistent with a low melt fraction over a broad area that is distributed asymmetrically on one side of the ridge. The asymmetry of the melt distribution is consistent with asymmetric spreading and a westward migration of the ridge in this area. [See the Perspective by Buck.]




To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)