Geophysical Studies of Volcanic and Tectonic Processes

DOUG TOOMEY Professor of Geophysics

My lab’s research focuses on earthquake and volcanic processes at volcanic hotspots and plate boundaries, including mid-ocean ridges and subduction zones. Our work also represents the university’s growing role in seismic monitoring in the PNW, for which we have led a push for additional onshore and offshore earthquake monitoring stations to be incorporated into a full West Coast Earthquake Early Warning System (http://shakealert.org).

Our research group is a pioneer in the use of ocean bottom seismology to study tectonic and volcanic processes. We have led scientific expeditions throughout the world, including the Atlantic, Pacific, and Mediterranean oceans. From 2006-2012 I chaired the Oversight Committee of the U.S. National Ocean Bottom Seismograph Instrument Pool (http://www.obsip.org). From 2011-2016 I was the team leader for the Cascadia Initiative (http://cascadia.uoregon.edu), a four-year $30 million project funded by the National Science Foundation (http://www.nsf.gov) to study the Cascadia Subduction Zone using an amphibious (onshore/offshore) array of seismic and geodetic instruments. Our research has been published widely in Nature, Science, Geology, Nature Geoscience, and specialty journals.

I am principal investigator for the Oregon component of the Pacific Northwest Seismic Network (https://pnsn.org), a cooperative operation between the University of Oregon and University of Washington to monitor earthquake and volcanic activity in the Pacific Northwest.  Sponsored by U.S. Geological Survey, U.S. Department of Energy, State of Washington and State of Oregon, the PNSN network monitors more than 400 seismograph stations and is dedicated to reducing the impact of earthquakes and volcanic eruptions by providing real-time information about ground motion and its causes.

I received my Ph.D. from the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution in 1990 and I have been on the faculty of the University of Oregon since 1990.

Research Projects:

Santorini Seismic Experiment

The Santorini Seismic Experiment is using seismic methods to examine the entire crustal magma plumbing system beneath Santorini volcano. Santorini is unique for this study because it recently experienced significant unrest; inflation of the ground and intense earthquake swarms during 2011-2013. It is also geologically well-studied. It is an ideal location because is a semi-submerged volcanic system which makes it possible to collect dense 3D marine-land seismic data.


 

Cascadia Initiative Expedition Team (CIET)

The Cascadia Initiative (CI) is an onshore/offshore seismic and geodetic experiment that takes advantage of an Amphibious Array to study questions ranging from megathrust earthquakes to volcanic arc structure to the formation, deformation and hydration of the Juan De Fuca and Gorda plates.
CIET_Oceanography_CoverbToomey, D.R., R.M. Allen, A.H. Barclay, S.W. Bell, P.D. Bromirski, R.L. Carlson, X. Chen, J.A. Collins, R.P. Dziak, B. Evers, D.W. Forsyth, P. Gerstoft, E.E.E. Hooft, D. Livelybrooks, J.A. Lodewyk, D.S. Luther, J.J. McGuire, S.Y. Schwartz, M. Tolstoy, A.M. Tréhu, M. Weirathmueller, and W.S.D. Wilcock. 2014. The Cascadia Initiative: A sea change in seismological studies of subduction zones. Oceanography 27(2):138–150

 


 

ENDEAVOUR/JUAN DE FUCA

The Endeavour seismic tomography experiment (ETOMO) experiment tests competing models for what controls the segmentation and intensity of ridge crest processes.  Existing models are at odds on the scale of mantle and crustal magmatic segmentation, the distribution of hydrothermal venting with respect to a volcanic segment and the properties of the thermal boundary layer that transports energy between the magmatic and hydrothermal systems. The recent discovery of an axial magma chamber (AMC) reflector beneath the Endeavour segment of the Juan de Fuca ridge, as well as systematic along axis changes in seafloor depth, ridge crest morphology and hydrothermal venting provide an ideal target for testing models of the origin of segmentation at mid-ocean ridges.

THE ROLE OF MAGMA INJECTION IN LOCALIZING BLACK SMOKER ACTIVITY, NATURE GEOSCIENCE, 2009

HOOFT, E. E. E., H. PATEL, W. WILCOCK, K. BECKER, D. BUTTERFIELD, E. DAVIS, R. DZIAK, K. INDERBITZEN, M. LILLEY, P. MCGILL, D. TOOMEY AND D. STAKES, A SEISMIC SWARM AND REGIONAL HYDROTHERMAL AND HYDROLOGIC PERTURBATIONS: THE NORTHERN ENDEAVOUR SEGMENT, FEBRUARY 2005, GEOCHEM. GEOPHYS. GEOSYST. , 11 , Q12015, DOI:10.1029/2010GC003264, 2010.


GALAPAGOS:

GO TO THE GALAPAGOS PAGE

Byrnes, J., E. E. E. Hooft, D. R. Toomey, D. R. Villagómez, D. J. Geist, and S. C. Solomon, An upper-mantle seismic discontinuity beneath the Galápagos Archipelago and its implications for studies of the lithosphere-asthenosphere boundary, Geochem. Geophys. Geosyst., in press.

 

ngeo_cover_FEB13Villagomez, D. R., D. R. Toomey, D. J. Geist, E. E. E. Hooft and S. C. Solomon, Mantle flow and multistage melting beneath the GalApagos hotspot revealed by seismic imaging, Nature Geoscience, doi:10.1038/NGEO2062, 2014.

 

Villagomez, D. R., D. R. Toomey, E. E. E. Hooft and S. C. Solomon, Crustal structure beneath the Galápagos Archipelago from ambient noise tomography and its implications for plume-lithosphere interactions, J. Geophys. Res., 116, B04310, doi:10.1029/2010JB007764, 2011.