During the past 65 million years, the Pacific Northwest has experienced significant tectonic and volcanic activity, including volcanism in the Yellowstone region. The origins of volcanism in the area have been debated.
To learn more about the region's tectonic activity and the underlying geologic structure, Obrebski et al. analyze high-resolution tomographic images of the Earth's interior created using data from the EarthScope USArray. They find that there is a mantle plume (a column of hot rock rising upward within the mantle) beneath the Yellowstone Snake River Plain in Idaho. In addition, they found that the Juan de Fuca slab, which is subducting under the North American plate, is fragmented beneath Oregon.
The researchers suggest that the plume's interaction with the slab contributed to the weakening and breakup of the Juan de Fuca slab. This unusual interaction between a subducting slab and a mantle plume could help explain tectonic and volcanic activity in the region.
Authors of the study include: Mathias Obrebski, Richard M. Allen: Department of Earth and Planetary Science, University of California, Berkeley, California, USA; Mei Xue: School of Ocean and Earth Science, Tongji University, Shanghai, China; Shu‐Huei Hung: Department of Geosciences, National Taiwan University, Taipei, Taiwan.
- Mathias Obrebski, Richard M. Allen, Mei Xue, Shu-Huei Hung. Slab-plume interaction beneath the Pacific Northwest. Geophysical Research Letters, 2010; 37 (14): L14305 DOI: 10.1029/2010GL043489
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