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We use broadband seismic data acquired by the St. Elias Erosion/Tectonics Project (STEEP) and the Alaska Earthquake Information Center to image the geometry of the subducting Yakutat Block in southeast Alaska. We combine results for both P-and S-wave receiver functions. P-wave to S-wave data were imaged with a fully three-dimensional wavefi eld imaging method centered on the STEEP region. The S-wave to P-wave data were imaged using a simpler common conversion point stacking method at two scales: a regional scale covering all of southeast Alaska and a smaller scale identical to the P-wave data. Our data confi rm that the southeastern Alaska subduction zone extends from the eastern end of the Aleutian Trench an additional 300 km to the Fairweather-Queen Charlotte fault system. We also locate the boundary between the Yakutat Block and North American Plate. We fi nd direct evidence that the subducted Yakutat Block and Pacifi c plate slabs are continuous and that Yakutat Block subduction extends from Prince William Sound to the east at least as far as Icy Bay. The dip angle of the slab ranges from 11° to 16° with a gradual increase from west to east across this region. Our data show a clear separation between the subducted Yakutat Block and the North American Plate under the Alaska Range, suggesting that deformation along the Denali fault and interior Alaska is not the product of coupling between North America and the subducted Yakutat Block. This dip angle also places the subducted Yakutat Block at the proper depth to produce arc magmatism found in the Wrangell volcanic fi eld. Modeling the geometry of the system suggests that sedimentary cover is being stripped at the western side of the Yakutat Block and the lower crust of the Yakutat Block is involved in the subduction. The system transitions from a single dipping megathrust on the western side of the Yakutat Block to intense shortening in the vicinity of Mount Saint Elias, where we suggest that the lower crust is likely undergoing ductile deformation and has thickened more than 60 km under the Peninsular terrane.

We merge structural results from the ST. Elias Erosion/tectonics Project (STEEP), other studies, and seismicity data to build a comprehensive, three-dimensional model of the lithosphere of the subduction corner in southern Alaska. The model is defined by three surfaces: (1) a top of the subducting lithosphere surface, (2) Moho surfaces, and (3) a base of subducting lithosphere surface. We model the eastern edge of the subducting lithosphere using the southern tip of the Yakutat microplate as an anchor. Kinematic reconstructions using that anchor suggest the modern Fairweather fault is likely inherited from motion of the margin in the 6–10 Ma period. We constructed a 4D kinematic model of crustal deformation in the vicinity of Mount St. Elias. We call this model the middlebuster model because the geometry is similar to a two-sided plow with that name. The west side of the plow is the eastern limit of the Aleutian megathrust constructed from the union of constraints from STEEP seismic results and slip models of the 1979 St. Elias earthquake. The east side is inferred from geologic mapping and slip models of the 1899 Yakutat Bay earthquake sequence. The top of the plow is near the Seward Glacier, where previous studies showed near world-record exhumation rates. GPS velocity vectors show a large rotation across the syntaxis at Mount St. Elias. West of the syntaxis, faults inferred from inversion of the GPS data are above the megathrust inferred from seismic imaging. That and other evidence suggest the presence of a wedge of ductile crust that partially decouples the subducting mantle lithosphere from the upper crust in the area near the suture with the Yakutat microplate.

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Skidmore is a small liberal arts College with 1,800 residential students. Nearly every student has their own computer and some have more than one, so support is becoming an ever increasing challenge. With viruses, worms and spyware running rampant in the residence halls, the support burden on the help desk was increasing significantly every semester. The help desk has one full time employee (the coordinator) and nineteen student assistants. Add to this an aging infrastructure and the cost of adding packet shaping, firewalls, computer registration systems and intrusion detection, and you can see that the costs of support, both in time and hardware, was bringing us to our knees. As part of a report to the College Administration about the state of the infrastructure several alternatives were explored. One of these alternatives was outsourcing the entire student network. This paper will explore this alternative beginning with the existing support models and infrastructure. We will show the planned changes and then discuss the reality.