Df. Argus et Mb. Heflin, PLATE MOTION AND CRUSTAL DEFORMATION ESTIMATED WITH GEODETIC DATA FROM THE GLOBAL POSITIONING SYSTEM, Geophysical research letters, 22(15), 1995, pp. 1973-1976
We use geodetic data taken over four years with the Global Positioning
System (GPS) to estimate (1) motion between six major plates and (2)
motion relative to these plates of ten sites in plate boundary zones.
The degree of consistency between geodetic velocities and rigid plates
requires the (one-dimensional) standard errors in horizontal velociti
es to be similar to 2 mm/yr. Each of the 15 angular velocities describ
ing motion between plate pairs that we estimate with GPS differs insig
nificantly from the corresponding angular velocity in global plate mot
ion model NUVEL-1A, which averages motion over the past 3 m.y. The mot
ion of the Pacific plate relative to both the Eurasian and North Ameri
can plates is observed to be faster than predicted by NUVEL-1A, suppor
ting the inference from Very Long Baseline Interferometry (VLBI) that
motion of the Pacific plate has sped up over the past few m.y. The Eur
asia-North America pole of rotation is estimated to be north of NUVEL-
1A, consistent with the independent hypothesis that the pole has recen
tly migrated northward across northeast Asia to near the Lena River de
lta. Victoria, which lies above the main thrust at the Cascadia subduc
tion zone, moves relative to the interior of the overriding plate at 3
0% of the velocity of the subducting plate, reinforcing the conclusion
that the thrust there is locked beneath the continental shelf and slo
pe.