Crustal Motion Models Developed for Version 3.2 of the Horizontal Time-Dependent Positioning Utility

The Horizontal Time-Dependent Positioning (HTDP) software allows users to transform positional coordinates across time and between spatial reference frames. To provide this capability, the software includes numerical models for estimating interseismic horizontal crustal velocities in and around the United States, as well as numerical models for estimating the displacements associated with major (magnitude > 6.0) earthquakes in these same areas. Version 3.2 of HTDP was released in August 2012. This HTDP version introduces: (a) an improved model for estimating interseismic horizontal velocities in Alaska, (b) a model for estimating the postseismic motion associated with the M7.9 Denali Fault earthquake that occurred in central Alaska on November 3, 2002, and (c) an improved model for estimating interseismic horizontal velocities in the region of the conterminous United States, which is located east of longitude 107°W. The development and nature of these new models are discussed in this paper. [PUBLICATION ABSTRACT]