Alaska and Aleutian Primary Site


The Alaska and Aleutian Subduction Zone (AASZ) has been identified as high priority because its study can address a wide variety of questions outlined within the SCD science plan, addressing both ocean-continent and ocean-ocean subduction. The AASZ also offers important opportunities to leverage EarthScope activities, including the Plate Boundary Observatory (PBO), and proposed future deployment of the US Transportable Array, and also a long record of USGS work in the area. GeoPRISMS investigations in Alaska face some logistical challenges, and so will require a ramp-up period and significant advance planning.

From the Science Plan

Several Themes are outlined in the GeoPRISMS Science & Implementation Plans and some thematic studies and projects are now underway. If you would like to organize a group to begin developing a plan for studying one or more of the SCD themes please contact the GeoPRISMS Office.

Click on each theme below to see current projects and some remarks on that theme from the GeoPRISMS Implementation Plan.

Research questionsPlanning

There are numerous opportunities for GeoPRISMS research at the Alaska site; examples of outstanding research problems include:

  • What controls the segmentation of a siliciclastic-rich subduction zone into regions of distinct slip behavior?
  • What governs the size of earthquakes on the megathrust? What controls the up-dip and down-dip boundaries of the seismogenic zone?
  • How are melts delivered from the mantle to the arc crust and out of a volcano? What is the relationship between magmas that erupt and those that freeze in the crust?
  • How do the structure of the incoming plate and the over-riding crustal composition control variations in the composition of primary magmas along a volcanic arc?
  • How did subduction initiate beneath the Alaska Peninsula and the Aleutian Arc, and how did this influence the evolution of their magmatic systems and seismogenic zone?

Further information about these topics, a summary of existing datasets, and critical research efforts for GeoPRISMS studies can be found in Section 2.2 of the GeoPRISMS Implementation Plan.

GeoPRISMS investigations in Alaska will require close collaboration with EarthScope researchers. A workshop for planning the future deployment of USArray in Alaska was held before the EarthScope National Meeting (May 2011). A broader joint GeoPRISMS-EarthScope planning workshop was held during Fall 2011 to clarify common research objectives with both USArray and PBO, to select “Discovery Corridors” for study, and to outline detailed implementation plans and timelines considering available resources and infrastructure. The Alaska IP has been updated and is available for download on the Science Plan page.

Articles, News, and Research

Newsletter ArticlesOther Research and Articles

Alaska and Aleutian


SCD