Subduction Dynamics in the Arica Gap

Target of opportunity

To develop a collaborative effort with geologists and geophysicists at the U. of Chile to understand the dynamics of subduction in N. Chile and S. Peru.

The Arica Gap

Mejillones Peninsula and Atacama Desert viewed from Apollo

1995 Mw 8.1 postseismic slip history

Pritchard and Simons, 2004Combining seismology, GPS, and InSAR

Rationale for a CGPS network:

All “locked” SZ instrumented with CGPS have seen aseismic transients, InSAR sees hints of it in Chile.

Existing CGPS network in Chile/Peru too sparse to detect coherent transient motions

Long term strain and relationship to volcanism and slab geometry - Is there extension in the shallow crust in the Plateau?

Plateau Uplift rates (geodetic)?

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Other motivations/targets (speak up):

Structure, fluids, melt…

Permanent vs. elastic strain

•Coastal terraces

•Uplift rates (geologic/geodetic)

Role of slab geometry

Role of sediment flux

Volcanic flux/magma storage?

100% Field Exposure

Who is interested?

Specific activities?

Existing Data?

Seismic

InSAR

Geologic

Geochronologic

Petrologic

New data (Chilean priorities)?

CGPS

Field geology

Seismic deployments

How to Proceed?

We can look at maps now and return in a week after people have thought about it and possibly done some relevant homework