![cascadea subduction cascadea subduction](https://media.wired.com/photos/593364aaf682204f736991c9/master/w_1012,c_limit/calvertyfig2.jpg)
This feature suggests that the slab and the subslab asthenosphere are strongly coupled, and subslab mantle flow is formed by entrainment of the asthenosphere with the overriding slab. A novel three-dimensional model of the fluid stored deep in Earth's crust along the Cascadia Subduction Zone provides new insight into how the accumulation and. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact. The slab and subslab mantle exhibit the same RAN pattern: positive RAN in the Cascadia forearc whereas negative RAN under the Cascadia volcanoes and the back-arc. The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land-level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Trench-parallel FVDs occur in the subducting slab under the forearc, suggesting that the gently-dipping slab may still keep its original anisotropy produced at the mid-ocean ridge and modified at the outer-rise before subduction. Radial anisotropy (RAN) is negative (i.e., Vpv > Vph) in the crust and upper-mantle wedge beneath the Cascadia volcanoes and back-arc area, reflecting hot and wet upwelling flows associated with fluids from dehydration reactions of the young and warm Juan de Fuca plate that is subducting toward the northeast. It runs from Cape Mendocino, California, all the way up to Vancouver Island.
![cascadea subduction cascadea subduction](https://eos.org/wp-content/uploads/2020/02/cascadia-subduction-zone-usgs.jpg)
Fast-velocity directions (FVDs) of azimuthal anisotropy in the crust are generally trench-parallel, reflecting N-S compression along the Cascadia margin. A new report has been released detailing scenarios for a Cascadia Earthquake and the resulting influence on coastal communities. The Cascadia Subduction Zone is a more than 600-mile fault located 70-100 miles off the West coast of North America. The first P-wave tomography of 3-D azimuthal and radial anisotropy of the Cascadia subduction zone is determined by inverting local and teleseismic arrival-time data.