SLIDESHOW: Geologic illustrations explain the Cascadia subduction

News

SLIDESHOW: Geologic illustrations explain the Cascadia subduction

A new interest has sparked for some in the northwest, after the New Yorker's terrifying article on how the "big one" with the potential of a 8.7 to 9 magnitude will devastate Seattle and everything west of Interstate 5. In this slideshow, the Cascasdia Subduction Zone is explained in various images.

A map, courtesy of the Washington State Seismic Hazards Catalog, shows expected shaking intensity in Washington. The New Yorker writes the cooler colors indicate lighter shaking, the warmer ones greater intensity. Photo via the New Yorker.Click here to read how you can protect yourself.

According to the New Yorker, shows the actual shake map from the 2011 earthquake in Tohoku, Japan, and the anticipated one for the state of Oregon from the full Cascadia earthquake. Image courtesy of the Oregon Department of Geology and Mineral Industries (DOGAMI) via the New Yorker. Click here to read how you can protect yourself.

This shows what is going on in the subduction zone. "The Juan de Fuca plate, composed of dense oceanic crust and is covered in layers of sediment that has hardened into rock, is running into the North American plate," PNSN wrote on its blog. "Where they collide, the denser Juan de Fuca plate dives under (“subducts”) and the locked interface between the two is the Cascadia fault that breaks in magnitude 9-ish earthquakes every couple hundred years." (Image: PNSN)

This is a seismic line. It shows "the sediment on top of the Juan de Fuca plate is scraped off and folded and faulted in what is called the “accretionary wedge”, which is essentially a wrinkled up rug of rock. That is what we can see best in these preliminary images, but the deeper subducting plate should be more visible out once the experts work their processing magic." (Image: PNSN)

This map shows the seismic lines PNSN shot overlain on the topography of the sea floor. "You can see the outline of Gray’s harbor and Long Beach Peninsula at right. to orient yourself. The black wiggly north-south-ish line at left indicates where the Juan de Fuca plate begins to subduct. The black lines show where we collected data to create 2D seismic images." (Image: NOAA)

This image of the Cascade Subduction Zone, shows the location of the trench, the downgoing slab, the active volcanoes and some major earthquakes. Click here to read 7 things to know after the New Yorker article. (Image: National park Service)

This image shows Cascadia margin turbidite (a current of rapidly moving, sediment-laden water) canyons, channels and 1999-2002 core locations. Major canyon/channel systems are outlined in blue. (Image: oregonstate.edu)

At the Cascadia subduction zone, the Juan de Fuca plate dives beneath North America (illustration: Oregon Department of Geology and Mineral Industries)

The area of the Cascadia subduction zone -- and the aftershock zone. Click here for more information.

This shows Cascadia earthquake sources. Click here for more information. (Image: USGS)

Another rendering of the structure of the Cascadia subduction zone. (Image: USGS) Click here for more information.

1/12

A new interest has sparked for some in the northwest, after the New Yorker's terrifying article on how the "big one" with the potential of a 8.7 to 9 magnitude will devastate Seattle and everything west of Interstate 5. In this slideshow, the Cascasdia Subduction Zone is explained in various images.

Today's Gallery Headlines

Jimmy Carter ‘forever’ stamp

PHOTOS: 2025 AJC Photos of the Year

Coca-Cola first ad

PHOTOS: Coca-Cola ads over time

Alonzo Herndon

PHOTOS: Philanthropists leave mark on Atlanta

gainesville, thomas county central

PHOTOS: Thomas County Central pummels Gainesville for 5A state title

More Galleries

Georgia state Capitol Christmas tree

PHOTOS: Capitol lights up for Christmas holidays

World Cup draw party TKTKT

PHOTOS: Fans attend 2026 World Cup draw party in Atlanta

Randy Beck

'No body' homicide cases in Georgia

aajc 110625 anx cobb so equine

PHOTOS: Cobb County Sheriff's Office Equine Therapy Program