Cascadia Primary Site

The Cascadia Subduction Zone is one of the three Primary Sites for the Subduction Cycles and Deformation (SCD) Initiative (along with Alaska/Aleutians and New Zealand). Cascadia offers outstanding short- and intermediate-term opportunities, in particular leveraging existing and growing onshore and offshore infrastructure associated with EarthScope’s Plate Boundary Observatory (PBO), and deployment of the EarthScope-MARGINS (now GeoPRISMS) Amphibious Array, all part of the ARRA-funded Cascadia Initiative. Work in this region will also build upon a broad spectrum of geological and geophyscial data collected over the past decades and can engage a range of US, Canadian, and international scientists.

From the Science Plan

  • The Cascadia Subduction Zone offers many exciting research questions. Examples of outstanding research problems include:
  • How does the balance of sediment accretion and subduction change with time and what effect does this have on the development of an accretionary wedge and a subduction channel?
  • What are the relationships between slow slip, non-volcanic tremor, great earthquakes, and the geological and geophysical conditions on the plate interface?
  • What causes the large compositional diversity of lavas and tephras erupted at many volcanic edifices in the Cascades and the along-strike variation in magma transport within the arc?
  • The Cascadia hot-slab paradox
  • What role do volatiles play in megathrust coupling/decoupling in this hot slab setting?
  • How did subduction initiate beneath Cascadia, and what was the role of the Siletzia terrane?

Further information about these topics, a summary of existing datasets, and critical research efforts for GeoPRISMS studies in Cascadia can be found in Section 2.3 of the GeoPRISMS Implementation Plan.

Cascadia Initiative

The Cascadia Initiative (CI) is a joint program between EarthScope and GeoPRISMS/MARGINS. The GeoPRISMS Website does not maintain a centralized web presence on behalf of the Cascadia Initiative, however more information can be found on the program website.