Seismic-Hazard Maps for Alaska and the Aleutian Islands: PGA250

Probabilistic seismic hazard maps were prepared for Alaska portraying
peak horizontal ground acceleration and horizontal spectral response
acceleration for 0.2, 0.3, and 1.0 second periods with probabilities
of exceedance of 10% in 50 years and 2% in 50 years. This particular
data set is for peak horizontal acceleration with a 2% probability
of exceedance in 50 years. All of the maps were prepared by combining
hazard derived from spatially-smoothed historic seismicity with hazard
from fault-specific sources. The acceleration values contoured are
the random horizontal component. The reference site condition is firm
rock, defined as having an average shear-wave velocity of 760 m/sec
in the top 30 meters corresponding to the boundary between NEHRP site
classes B and C.
This data set represents the results of calculations of hazard curves
for a grid of points with a spacing of 0.1 degrees in latitude and
longitude. The grid of points were contoured to produce the final
representation of the seismic-hazard.