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Allen CV
Seismo Lab
Earth & Planetary
UC Berkeley

Oregon Array for Teleseismic Study

See also: FACES and Mendocino experiments

On this page:
Results | Deployment | Newsletters | Publications and presentations | Acknowledgements

Experiment results

Preliminary results from the ongoing experiment. See also the publications and presentations section.

Episodic tremor and slip (ETS)
By combing data from geodetic and seismic sensors throughout Cascadia a catalog of ETS events has been developed for the subduction zone. From 2000 to 2006 there where 22 months during which an ETS event occurred, i.e. an average of one every 3.3 months. Find animations of ETS events, a one-page summary presented to NEPEC and a manuscript detailing the catalog. more...

Tomography
Preliminary seismic tomography images along the OATS array show the Juan de Fuca plate subducting beneath Oregon. The slab has not been visible in previous studies east of the high Cascades leading to questions about the fate of the slab. Here is clearly imaged diving into the mantle beneath the Newberry track along the High Lava Plains.

Seismic anisotropy
SKS splitting observations were used to map the orientation of minerals in the mantle beneath the OATS line. Interpreting the seismically fast direction as parallel to mantle flow, Xue and Allen 2006 conclude that there is little or no flow in the mantle along the Newberry hotspot track. This precludes several of the previously proposed mechanisms for the formation of the hotspot and suggests that the track may be the product of a lithosphere-controlled process.

For more information see:
Xue, M. and R.M. Allen (2006) Origin of the Newberry Hotspot Track: Evidence from shear-wave splitting. Earth Planet. Sci. Lett. 244, 315-322, doi:10.1016/j.epsl.2006.01.066. abstract | reprint

The deployment

OATS is a deployment of broadband seismic station across Oregon. The line extends from the McDermitt Caldera to the northwest along the Newberry track, past the Newberry Caldera, over the High Cascades and on to the coast within ~100 km of the trench. The array will provide data to constrain the subsurface structure associated with the Newberry track and caldera, and the subducted Juan de Fuca slab using the large number of teleseismic earthquake sources within a few degrees of the array azimuth.

Photos from the May 2003 deployment

Project overview web pdf

OATS Newsletters

Information and project updates for our participating landowners hosting OATS instruments. The newsletters were prepared by Mei Xue.

Publications and presentations

Publications to date
Xue, M. and R.M. Allen (2006) Origin of the Newberry Hotspot Track: Evidence from shear-wave splitting. Earth Planet. Sci. Lett. 244, 315-322, doi:10.1016/j.epsl.2006.01.066. abstract | reprint

Conference abstracts to date
Xue, M. and R.M. Allen, (2005) Seismic imaging of the Newberry hotspot track. AGU Fall Meeting 2005. abstract

Xue, M. and R.M. Allen (2005) Identifying the Origin of the Newberry Hotspot Track. Chapman Conference: The Great Plume Debate. Fort William, Scotland. August 2005. abstract

Allen, R.M. and M. Xue (2005) The origin of hotspot volcanism in the Pacific Northwest. IRIS/UNAVCO Annual Meeting abstract

Xue, M. and R.M. Allen, (2004) Upper Mantle Origin of the Newberry Hotspot Track: Evidence From Shear-Wave Splitting, AGU Fall Meeting 2004. abstract

Allen, R.M., and M. Xue (2004) Newberry upwelling and Cascadian subduction: Convective interactions in the mantle beneath Oregon, MYRES Conference. abstract

Acknowledgements

Support for this project was provided by the National Science Foundation, the University of California, Berkeley, the University of Wisconsin, Madison, and Oregon State University.



For more information contact Richard Allen.


© Richard M Allen