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GPS velocity field for the Tien Shan and surrounding regions
Author(s) -
Zubovich Alexander V.,
Wang Xiaoqiang,
Scherba Yuri G.,
Schelochkov Gennady G.,
Reilinger Robert,
Reigber Christoph,
Mosienko Olga I.,
Molnar Peter,
Michajljow Wasili,
Makarov Vladimir I.,
Li Jie,
Kuzikov Sergey I.,
Herring Thomas A.,
Hamburger Michael W.,
Hager Bradford H.,
Dang Yamin,
Bragin Vitaly D.,
Beisenbaev Rinat T.
Publication year - 2010
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/2010tc002772
Subject(s) - geology , longitude , clockwise , structural basin , crust , global positioning system , seismology , central asia , fault (geology) , latitude , paleontology , geodesy , physical geography , fold (higher order function) , geography , telecommunications , computer science , mechanical engineering , engineering
Measurements at ∼400 campaign‐style GPS points and another 14 continuously recording stations in central Asia define variations in their velocities both along and across the Kyrgyz and neighboring parts of Tien Shan. They show that at the longitude of Kyrgyzstan the Tarim Basin converges with Eurasia at 20 ± 2 mm/yr, nearly two thirds of the total convergence rate between India and Eurasia at this longitude. This high rate suggests that the Tien Shan has grown into a major mountain range only late in the evolution of the India‐Eurasia collision. Most of the convergence between Tarim and Eurasia within the upper crust of the Tien Shan presumably occurs by slip on faults on the edges of and within the belt, but 1–3 mm/yr of convergence is absorbed farther north, at the Dzungarian Alatau and at a lower rate with the Kazakh platform to the west. The Tarim Basin is thrust beneath the Tien Shan at ∼4–7 mm/yr. With respect to Eurasia, the Ferghana Valley rotates counterclockwise at ∼0.7° Myr −1 about an axis at the southwest end of the valley. Thus, GPS data place a bound of ∼4 mm/yr on the rate of crustal shortening across the Chatkal and neighboring ranges on the northwest margin of the Ferghana Valley, and they limit the present‐day slip rate on the right‐lateral Talas‐Ferghana fault to less than ∼2 mm/yr. GPS measurements corroborate geologic evidence indicating that the northern margin of the Pamir overthrusts the Alay Valley and require a rate of at least 10 and possibly 15 mm/yr.