News FocusGeophysics

Scoping Out Unseen Forces Shaping North America

See allHide authors and affiliations

Science  25 Sep 2009:
Vol. 325, Issue 5948, pp. 1620-1621
DOI: 10.1126/science.325_1620a

You are currently viewing the summary.

View Full Text

Summary

As it sweeps across America, the USArray network of seismometers is revealing an impressive but often befuddling subsurface menagerie of slabs, drips, and plumes. Clearly, the great blobs and chunks of rock rising, sinking, or just floating beneath the surface of the western United States bear some relation to overlying mountains, basins, and volcanic outpourings, but even the avalanche of new data can't always resolve exactly what the imaged features are or how they are shaping the surface. Already, the new images have added fuel to a long-running debate over the existence of mantle plumes, tall columns of hot rock rising thousands of kilometers from deep in the lower mantle like smoke from a stack. The putative plume beneath Yellowstone was among the most suspect of some 30 proposed plumes. But with USArray it's coming back.