CASCADIA SUBDUCTION ZONE
Copyright infringement not intended
Picture Courtesy: https://ktvl.com/
Context: A comprehensive survey of the Cascadia Subduction Zone reveals complex structures, segmentation, and geological features, aiding earthquake forecasting efforts.
Details
- A new study, published in Science Advances, has produced the first comprehensive survey of the complex structures beneath the seafloor of the Cascadia Subduction Zone, a 600-mile-long strip off the coasts of southern British Columbia, Washington, Oregon, and northern California.
|
Subduction Zone ●A subduction zone is a region along Earth's crust where two tectonic plates meet and collide, creating a geologically significant and potentially hazardous area. The process involves the convergence of denser oceanic crust with a less dense continental or another oceanic plate, known as subduction. ●The subducting plate plunges into the mantle, where it can be recycled back into the Earth's interior. Subduction zones have a deep oceanic trench, an accumulation wedge, and a volcanic arc, releasing trapped water that lowers the melting point of the overlying mantle rock, forming a chain of volcanoes. ●These zones are hotspots for earthquakes, with megathrust earthquakes occurring along their boundaries. They play a crucial role in shaping Earth's surface features, contributing to mountain building and recycling crust. ●Understanding subduction zones is vital for assessing earthquake and volcanic eruption risks, developing better prediction models, and developing preparedness strategies. |
Cascadia Subduction Zone (CSZ)
- It is a 960 km fault located off the Pacific coast, extending from northern Vancouver Island in Canada to Northern California in the United States.
- It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30 m.
- The zone is a long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the larger mostly continental North American Plate.
- The region is influenced by tectonic processes such as accretion, subduction, deep earthquakes, and active volcanism of the Cascades.
- Notable eruptions include Mount Mazama 7,500 years ago, Mount Meager massif 2,350 years ago, and Mount St. Helens in 1980.
Source:
|
PRACTICE QUESTION Q. Which of the following conditions are most likely to be present at a subduction zone? 1. A deep oceanic trench on the side of the denser plate. 2. A volcanic arc on the side of the overriding plate. 3. A mountain range on the side of the subducting plate. 4. A zone of high seismic activity along the plate boundary. 5. A region where a new oceanic crust is being created. How many of the above statements are correct? A) Only two B) Only three C) Only four D) All five Answer: B |
1.png)
