Transcript Document

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
Combining seismology, GPS, and InSAR
Pritchard and Simons, 2004
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)?
___________
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
How to Proceed?
Geochronologic
We can look at maps now and
return in a week after people
have thought about it and
possibly done some relevant
homework
Petrologic
New data (Chilean priorities)?
CGPS
Field geology
Seismic deployments