GPS Records Variable Deformation across a Subduction Zone

How does deformation change the land above a subduction zone?

Recent data from the Pacific Northwest and other subduction zones show that there are 3 distinct areas of movement above a subduction zone: 1) constant movement above the locked leading edge, 2) see-saw pattern of back-&-forth movement above a zone that alternately locks then slips in a process called episodic tremor and slip , and 3) no movement far inland above the deeper part of the diving oceanic plate.


Keypoints:

  • Subduction zones have variable stress
  • Three graphs represent compressional stress in different subduction regions
  • Near-trench overlying plate shows steady compression and deformation
  • The transition zone graph has a sawtooth pattern indicating periodic slip
  • Flat pattern inland indicates the subducting plate is not locked

Total Time: 1min 17s
Level: Novice

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