National park service sites in the coastal ranges of washington oregon and northern california contain rugged mountains of rocks that were manufactured in the ocean then scraped off the plate and lifted out of the sea.
Sea floor feature cascadia subduction zone deep sea trench.
The process by which ocean floor sinks beneath a deep ocean trench and back into the mantle is called subduction sub duk shun.
What are deep sea trenches.
Features of the ocean include the continental shelf slope and rise.
Oceanic trenches are a distinctive morphological feature of convergent plate boundaries along which lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year.
As subduction occurs crust closer to a mid.
These oceanographic features are the deepest parts of the ocean floor.
Deep sea trenches are the topographic expressions of a subduction zone.
Features rising up from the ocean floor include seamounts volcanic islands and the mid oceanic ridges and rises.
Deep sea trenches generally lie seaward of and parallel to adjacent island arcs or mountain ranges of the continental margins they are closely associated with and found in subduction zones that is locations where a lithospheric plate bearing oceanic crust slides down into the upper mantle under the force of gravity.
The ocean floor is called the abyssal plain.
Below the ocean floor there are a few small deeper areas called ocean trenches.
Oceanic trenches are topographic depressions of the sea floor relatively narrow in width but very long.
Where the subducting slab bends downward a deep sea trench forms.
Trenches capture a lot of sediment from nearby land masses much of which is carried down along with the slab.
4 25 and deep zone of stable sliding extending beneath the volcanic arc.
The pacific northwest is an exciting place to observe geologic processes in action.
Cross section through cascadia subduction zone showing subdivision into a zone of stable sliding closest to the trench the locked zone subject to great earthquakes the zone of episodic tremor and slip possibly related to high fluid pressure epicenters in fig.
The probable explanation lies in the rate of convergence between the juan de fuca and north american.
Ocean trenches and accretionary wedges.
In a process taking tens of millions of years part of the ocean floor sinks back into the mantle at deep ocean trenches.
There are some unusual features at the cascade subduction zone where the juan de fuca plate sinks beneath the north american plate there is no deep trench seismicity earthquakes is less than expected and there is evidence of a decline in volcanic activity over the past few million years.
Deep sea trench a narrow elongated depression of the deep ocean floor parallel to the trend of a volcanic arc.
Where is the cascadia subduction zone and what happens there what are deep sea trenches a narrow elongated depression of the deep ocean floor parallel to the trend of a volcano arc.
Cascadia subduction zone in the pacific northwest of the united states.
It separates the juan de fuca and north america plates.
