Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Crust And Upper Mantle Velocity Structure Of The Yellowstone Hot Spot And Surroundings, D. L. Schutt, Ken Dueker, H. Yuan
Crust And Upper Mantle Velocity Structure Of The Yellowstone Hot Spot And Surroundings, D. L. Schutt, Ken Dueker, H. Yuan
Ken Dueker
The Yellowstone hot spot has recently been shown to be a plume that extends into the transition zone. At roughly 60-120 km depth, the plume material rising beneath Yellowstone Park is sheared SW by North America Plate motion, producing a profound low velocity layer emplaced beneath the thin lithosphere. To constrain the absolute seismic velocity of the plate-sheared plume layer, fundamental mode Rayleigh wave observations have been inverted for phase velocity using the two plane wave technique. The resulting phase velocity models are inverted with Moho-converted P to S arrival times to better constrain crustal thickness and absolute S wave …
Crustal Structure And Thickness Along The Yellowstone Hot Spot Track: Evidence For Lower Crustal Outflow From Beneath The Eastern Snake River Plain, H. Yuan, Ken Dueker, J. Stachnik
Crustal Structure And Thickness Along The Yellowstone Hot Spot Track: Evidence For Lower Crustal Outflow From Beneath The Eastern Snake River Plain, H. Yuan, Ken Dueker, J. Stachnik
Ken Dueker
Receiver functions from seismic stations about the Yellowstone hot spot track are migrated to depth using a Vp/Vs map constructed from stacking of the direct and free surface Moho reverberations (i.e., H-K analysis) and a shear velocity tomogram constructed from surface wave measurements. The thickest crust (48-54 km) resides in the Wyoming province beneath the sampled Laramide age blocks, and the thinnest crust (32-37 km) resides in the Montana Basin and Range province. The eastern Snake River Plain (ESRP) crust is thickest (47 km) at its NE end beneath the young calderas and thinnest (40 km) at its SW end …
Characterizing The 410 Km Discontinuity Low-Velocity Layer Beneath The La Ristra Array In The North American Southwest, J. J. Jasbinsek, Ken Dueker, S. M. Hansen
Characterizing The 410 Km Discontinuity Low-Velocity Layer Beneath The La Ristra Array In The North American Southwest, J. J. Jasbinsek, Ken Dueker, S. M. Hansen
Ken Dueker
Receiver functions recorded by the 54-station 920 km long Program for Array Seismic Studies of the Continental Lithosphere-Incorporated Research Institutions for Seismology Colorado Plateau/Rio Grande Rift Seismic Transect Experiment (LA RISTRA) line array display a pervasive negative polarity P to S conversion (Pds) arrival preceding the positive polarity 410 km discontinuity arrival. These arrivals are modeled as a low-velocity layer atop the 410 km discontinuity (410-LVL) and are inverted for a velocity profile via a grid search using a five-parameter linear gradient velocity model. Model parameter likelihood and correlations are assessed via calculation of one-and two-dimensional marginal posterior probability distributions. …
A Sporadic Low-Velocity Layer Atop The Western Us Mantle Transition Zone And Short-Wavelength Variations In Transition Zone Discontinuities, B. Schmandt, Ken Dueker, S. M. Hansen, J. J. Jasbinsek, Z. Zhang
A Sporadic Low-Velocity Layer Atop The Western Us Mantle Transition Zone And Short-Wavelength Variations In Transition Zone Discontinuities, B. Schmandt, Ken Dueker, S. M. Hansen, J. J. Jasbinsek, Z. Zhang
Ken Dueker
Teleseismic receiver function analysis of data from six dense arrays in the western U. S. is used to investigate mantle transition zone (MTZ) discontinuities and the prevalence of a low-velocity layer atop the 410 km discontinuity (410-LVL). Negative polarity Ps arrivals indicative of a low-velocity layer with a top 25-60 km above the 410 are identified in 8-11 out of 18 stacks of receiver functions from highly sampled back azimuth corridors. The 410-LVL is interpreted as partial melt resulting from upwelling of hydrated mantle across a water solubility contrast at the 410. The 669 km mean depth of the 660 …
Teleseismic P-Wave Tomogram Of The Yellowstone Plume, H. Y. Yuan, Ken Dueker
Teleseismic P-Wave Tomogram Of The Yellowstone Plume, H. Y. Yuan, Ken Dueker
Ken Dueker
Inversion of a new data set of teleseismic P-wave travel-times from three PASSCAL seismic deployments around the Yellowstone hotspot reveals a 100 km diameter upper mantle plume that extends from the Yellowstone volcanic caldera to 500 km depth and dips 20 degrees to the northwest. A monotonic decrease in the velocity perturbation of the plume from -3.2% at 100 km to -0.9% at 450 km is consistent with a uniform thermal anomaly of 180 degrees C. Where the plume crosses the 410 km discontinuity, previous research shows a depression in the 410 km discontinuity consistent with a warm plume ( …
Signal-To-Noise Ratios Of Teleseismic Receiver Functions And Effectiveness Of Stacking For Their Enhancement, I. B. Morozov, Ken G. Dueker
Signal-To-Noise Ratios Of Teleseismic Receiver Functions And Effectiveness Of Stacking For Their Enhancement, I. B. Morozov, Ken G. Dueker
Ken Dueker
[1] We present a method for the measurement of spatially variable signal-to-noise (S/N) ratios in multichannel teleseismic receiver function (RF) images. The S/N ratio is defined as a measure of coherency of the final image, and the approach is applicable to any RF imaging technique that employs mapping of the records into depth followed by their summation as the final signal enhancement step. In such methods, all of the converted phases become horizontally aligned in the depth domain, and their coherent (signal) and incoherent (noise) components can be estimated by using stacking statistics. For 10 locations along two subarrays of …
Upper Mantle P-Wave Velocity Structure From Passcal Teleseismic Transects Across Idaho, Wyoming And Colorado, Ken Dueker, H. Y. Yuan
Upper Mantle P-Wave Velocity Structure From Passcal Teleseismic Transects Across Idaho, Wyoming And Colorado, Ken Dueker, H. Y. Yuan
Ken Dueker
Inversion of teleseismic P-time residuals along two linear seismic arrays provides well-resolved inverse images of the upper mantle. Low velocity bodies beneath the Yellowstone Hotspot Track and the Grand Mesa volcanic field in western Colorado are similar in shape and magnitude. In the two places where our transects cross the 1.78 Ga Archean-Proterozoic Cheyenne suture, high velocities are imaged to 150 km. Beneath the Leucite Hills volcanic field in Wyoming a small upper mantle low velocity body is imaged. Whether these anomalies are lithospheric or asthenospheric in origin is poorly constrained, but the consistent high velocities beneath the Cheyenne suture …