The ITRF96 realization and its associated velocity field

Plate kinematics have been derived from GPS site velocities spanning Australasia and the western Pacific and define a framework in which deformation fields at plate boundaries can be investigated. The Australian Plate appears to be rigid from Cocos Island in the west to Noumea in the east and incorporating all of the Australian continent. A revision of the angular velocity vector of the Pacific Plate using six site velocities has led to the detection of significant relative motion between the Pacific Plate and sites in northern Papua New Guinea. This provides strong evidence in support of a North Bismarck Plate between the South Bismarck and Pacific Plates and we model the motion of the North Bismarck Plate with the angular velocity vector (45.0°S, 126.4°E, 0.85°/Myr). These new angular velocity vectors model the rigid plate motions of a substantial part of the Australasian and western Pacific regions with an accuracy better than 3 mm/yr.

Section: Pacific Platementioning

confidence: 94%

Plate kinematics in the western Pacific derived from geodetic observations

Tregoning

2002

“…Analysis of campaign-mode data consists of several steps: daily solutions derived with weak constraints on initial positions are determined using global orbit products; both the campaign data and continuous stations from the region and from tectonically stable regions of interior North America are included in this analysis. The weakly constrained daily frame is transformed to the International Terrestrial Reference Frame (ITRF96) Sillard et al, 1998] using JPL daily frame files. Daily and seasonal irregularities in the global reference frame are minimized using a regional stabili- (Table 3).…”

Section: Discussionmentioning

confidence: 99%

Refined kinematics of the eastern California shear zone from GPS observations, 1993–1998

Miller¹,

Johnson²,

Dixon³

et al. 2001

156

119

“…Random walk style perturbations were allowed for some parameters whose errors were found correlated with time (e.g., the Earth's rotation parameters and the antenna heights at a few sites). For more details about the data analysis procedure and uncertainty estimation, please refer to Shen et [Sillard et al, 1998] (see also http:/lareg.ensg.ign.fr/ITRF/ ITRF97) to constrain our solution. We chose as our reference stations those whose formal ITRF97 velocity uncertainties are <0.5 mm/yr.…”

Section: Gps Data Collection and Analysismentioning

confidence: 99%

Crustal deformation along the Altyn Tagh fault system, western China, from GPS

Shen¹,

Wang²,

Yan-xing³

et al. 2001

189

166

Abstract. We collected GPS data from the southern Tarim basin, the Qaidam basin, and the western Kunlun Shan region between 1993 and 1998 to determine crustal deformation along the Altyn Tagh fault system at the northern margin of the Tibetan plateau. We conclude from these data that the Altyn Tagh is a left-lateral strike slip fault with a current slip rate of •9 mm/yr, in sharp contrast with geological estimates of 20-30 mm/yr. This contrast poses an enigma: because the GPS data cover a wider region than the geologic data, they might be expected to reveal somewhat more slip. We also find that the Tarim and Qaidam basins behave as rigid blocks within the uncertainty of our measurements, rotating clockwise at a rate of •11 and •4.5 nrad/yr, respectively, with respect to the Eurasia plate. The rotation of the Tarim basin causes convergence across the Tian Shan, increasing progressively westward from •6 mm/yr at 87øE to •18 mm/yr at 77øE. Our data and other GPS data suggest that the Indo-Asia collision is mainly accommodated by crustal shortening along the main Himalayan thrust system (•53%) and the Tian Shan contractional belt (•19%). Eastward extrusion of the Tibetan plateau along the Altyn Tagh and Kunlun faults accommodates only •23% of the Indo-Asia convergence.