The accompanying map shows the PANGA Investigator Community plan for backbone stations as part of PBO. Beyond the fiducial rationale for the backbone, there are key scientific issues that will be addressed by this network enhancement.
To determine the kinematics and margins of the Basin and Range,
the Olympic Wallowa lineament, the Yakima fold and thrust belt,
the Lewis and Clark line, and the Rocky Mountain trench. These
differing structural domains define the Cascadia back-arc and
accommodate broad deformation between the convergent margin and
the continent. They also play a key role in how deformation styles
in adjacent regions that lie to the north and south of the respective
triple junctions interact with back arc deformation.
The partitioning of regional defomation constrains the rheology and
dynamics of continental tectonics.
The role of the Cascade magmatic arc in accommodating or driving regional
deformation, especially in the region of the Cascade graben, is a key
regional tectonic element that is not addressed by any current observations.
Even the Cascade fore-arc, which is deforming in response to the subduction
along the fastest fault in the conterminous U.S., is not yet adequately
observed at PBO back bone station densities.
We planned to a 150 km spacing, realizing that resources are insufficient to support the targeted 100 km spacing.
The maps show existing and planned/funded stations in the Pacific Northwest which are on geodetic grade monuments in blue and the enhanced backbone in red. The backbone request includes 39 stations in the U.S., including two VLBA sites, and 51 new stations in Canada. We realize that the Canadian stations may ultimately be funded from a different source, but they are a key component of the scientific rationale for PBO and we choose to show them here.
The stations in the U.S. are in road accessible areas; some (10-15%) may require autonomous installations or at least telemetry. The stations in the Canadian Cordillera are all in locations with power and land phone lines.
This request excludes the Rocky Mountain region in the conterminous U.S. We have not yet consulted with other groups who may have possible overlap such as the EBRY, BARGEN, and BARD. As many as six to eight stations may overlap with othersŐ interest areas. Finally, if all Cascadia cluster proposals were funded, a savings of six stations could be achieved through overlap.
Click here for a list of station coordinates.
For additional information, contact Meghan Miller.
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Last updated 17 October 2000