APPLICATION OF LOW-PASS DIRECTIONAL FILTERING TECHNIQUES TO AEROMAGNETIC DATA IN ORDER TO BETTER DETERMINE RELATIONSHIPS BETWEEN SEISMICITY AND DEEP STRUCTURE ANOMALIES WITHIN CENTRAL INTERIOR ALASKA ALONG THE DENALI FAULT

The interior of central Alaska is an area where outcrop exposure is poor due to the swampy, glaciated, and densely vegetated terrain. Several active, northeast trending zones of seismicity occur in this region that serve to transfer stress northward from the right lateral strike slip Denali Fault and the neighboring Foothills thrust system to interior Alaska. Aeromagnetic survey data collected throughout the region by the U.S. Geological Survey provides complimentary insight into how historic and recent seismic data corresponds to magnetic anomalies that reflect regional geologic variations not visible at the surface. By applying a low-pass directional filter at both 10km and 15km wavelength cutoff depths, striking between 30 and 60 degrees northeast, it is possible to examine the relationship between these deep structure crustal anomalies and the corresponding seismic zones contained within the study area. Preliminary comparisons suggest nucleation points and rupture termination points for M>6.5 historic (pre-1971) earthquakes may be related to the deeper crustal structures imaged by the magnetic data.