Results 51 to 60 of about 202 (128)
Evolution in Fluid Composition During Subduction
Abstract Fluid‐rock reactions play important roles in seismicity, arc‐magma chemistries, and volatile cycling at convergent plate boundaries. In subduction environments, metamorphic reactions involving hydrous fluids facilitate metasomatic alteration and mass transport.
A. A. Helm, M. J. Caddick, R. J. Bodnar
wiley +1 more source
Lithium isotope fractionation in the southern Cascadia subduction zone
We present lithium (Li) abundances and isotope compositions for a suite of anhydrous olivine tholeiites (HAOTs) and hydrous basalt-andesitic (BA) lavas from the Mt. Shasta and Medicine Lake regions, California. The values of δ7Li vary from + 0.9‰ to + 6.4‰ and correlate inversely with distance from the trench.
Magna, T +3 more
openaire +1 more source
Tsunamigenic megathrust earthquakes along the Cascadia subduction zone present a major hazard concern. We can better prepare to model the earthquake source in a rapid manner by imbuing fault geometry constraints based on prior knowledge and by ...
Kevin Kwong +4 more
doaj +1 more source
We employ an automatic earthquake detection algorithm to seismic waveforms recorded between the years 2000 and 2020 in southwest British Columbia. 32,121 events which possess at least three paired P‐ and S‐wave arrival times are located, compared to 21 ...
Reid J. Merrill +4 more
doaj +1 more source
Dynamic Evolution of Forearc Subsidence Controlled by Slab Geometry
Abstract Several subduction zones worldwide present an enigmatic forearc topography and strain characterized by extension at a forearc ridge near the trench and shortening within a forearc valley located between the ridge and the magmatic arc. The development of this topography has been linked to progressive slab steepening, while strain patterns ...
F. Bolrão, W. P. Schellart
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Seismic evidence for melt-rich lithosphere-asthenosphere boundary beneath young slab at Cascadia
The Lithosphere-Asthenosphere Boundary (LAB) beneath oceanic plates is generally imaged as a sharp seismic velocity reduction, suggesting the presence of partial melts.
Xin Wang +5 more
doaj +1 more source
Poloidal‐ and Toroidal‐Mode Mantle Flows Underneath the Cascadia Subduction Zone
Several hypotheses have been proposed to explain intriguing circular shear wave splitting patterns in the Pacific Northwest, invoking either 2‐D entrained flows or 3‐D return flows. Here, we present some hitherto unidentified, depth‐dependent anisotropic
Hejun Zhu +4 more
doaj +1 more source
At the northern Cascadia subduction zone, the subducting Explorer and Juan de Fuca plates interact across a transform deformation zone, known as the Nootka fault zone (NFZ).
Jesse Hutchinson +7 more
doaj +1 more source
Abstract The Ecuadorian margin is a forearc‐arc system shaped by oceanic terrane accretion and Carnegie Ridge subduction, yet the accretion mechanism and ridge subduction extent remain poorly constrained. Using teleseismic P‐wave receiver functions from dense seismic arrays, we image velocity discontinuities within the overriding plate and subducting ...
Cong Li +11 more
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Tectonic Tremor Reveals Slow Deformation Along the Antarctic–South American Subduction Zone
Abstract The Antarctic–South American subduction zone is among the least explored convergent margins and lacks documented large interplate earthquakes despite ongoing convergence. Here we report the discovery of tectonic tremor along this plate boundary using continuous seismic data.
K. Azúa, S. Ruiz, S. Ide
wiley +1 more source

