TY - JOUR
T1 - Crustal Deformation of South Korea After the Tohoku-Oki Earthquake
T2 - Deformation Heterogeneity and Seismic Activity
AU - Kim, Sungshil
AU - Ree, Jin Han
AU - Yoon, Ha Su
AU - Choi, Byung Kyu
AU - Park, Pil Ho
N1 - Funding Information:
We thank two reviewers and the Editor, Nathan Niemi, for their constructive comments which significantly improved the manuscript. This research was supported by grant KMIPA 2017-9030 from Weather-Earthquake See-At Technology Development of the Korea Meteorological Industry Promotion Agency. Our velocity data can be found in Table S1 and S2 of the supporting information, and the used MATLAB scripts and preprocessed GPS data can be obtained from the repository (https://zenodo.org/record/1250053#. Wz2vMtIzbAQ).
PY - 2018/8
Y1 - 2018/8
N2 - Although the 2011 Tohoku-Oki earthquake (Mw 9.0, 11 March 2011) occurred more than 1,000 km from South Korea, it significantly changed the magnitudes and orientations of Global Positioning System (GPS) velocity vectors in the country, which took two years to return to preearthquake values. Then, areas with relatively thick crust show contractional surface deformation, whereas areas with thinner crust show dilatation, suggesting that the deformation pattern is long-term. Although there is no one-to-one correlation between earthquakes and surface deformation, earthquakes tend to be concentrated in areas with higher shear strain rates. In South Korea, the stress field inferred from earthquake data is inconsistent with surface deformation calculated from GPS data. This may arise because stress orientations at earthquake focal depths are different from those at the surface, or surface deformation measured by GPS may represent interseismic elastic deformation leading to future large earthquakes, while recent earthquakes without surface ruptures might not contribute to the surface deformation. Some effects of crustal thickness on surface deformation and inconsistency between surface deformation from GPS data and kinematics from earthquake data may be a common feature of intraplate regions.
AB - Although the 2011 Tohoku-Oki earthquake (Mw 9.0, 11 March 2011) occurred more than 1,000 km from South Korea, it significantly changed the magnitudes and orientations of Global Positioning System (GPS) velocity vectors in the country, which took two years to return to preearthquake values. Then, areas with relatively thick crust show contractional surface deformation, whereas areas with thinner crust show dilatation, suggesting that the deformation pattern is long-term. Although there is no one-to-one correlation between earthquakes and surface deformation, earthquakes tend to be concentrated in areas with higher shear strain rates. In South Korea, the stress field inferred from earthquake data is inconsistent with surface deformation calculated from GPS data. This may arise because stress orientations at earthquake focal depths are different from those at the surface, or surface deformation measured by GPS may represent interseismic elastic deformation leading to future large earthquakes, while recent earthquakes without surface ruptures might not contribute to the surface deformation. Some effects of crustal thickness on surface deformation and inconsistency between surface deformation from GPS data and kinematics from earthquake data may be a common feature of intraplate regions.
KW - 2011 Tohoku-Oki earthquake
KW - GPS network
KW - South Korea
KW - intraplate
KW - surface deformation
KW - velocity field
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U2 - 10.1029/2018TC004967
DO - 10.1029/2018TC004967
M3 - Article
AN - SCOPUS:85052615827
VL - 37
SP - 2389
EP - 2403
JO - Tectonics
JF - Tectonics
SN - 0278-7407
IS - 8
ER -