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The Complexity of the 2018 Kaktovik Earthquake Sequence in the Northeast of the Brooks Range, Alaska
Author(s) -
Xu Guangyu,
Xu Caijun,
Wen Yangmao,
Xiong Wei,
Valkaniotis Sotiris
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl088012
Subject(s) - geology , seismology , geodetic datum , sequence (biology) , fault plane , slip (aerodynamics) , fault (geology) , strike slip tectonics , aftershock , focal mechanism , geodesy , genetics , physics , biology , thermodynamics
We use mainly geodetic observations to constrain the fault geometry and coseismic distribution of the 2018 Kaktovik earthquake sequence, Alaska. We find that at least three faults were activated. The earthquake sequence ruptured mainly an ESE‐striking, SSW‐dipping strike‐slip fault and a secondary rupture on an SE‐striking, SW‐dipping normal fault. Slip also occurred on a small SSW‐striking fault plane, which is found first in geodetic data and further verified with geological data and focal mechanism solutions. We also map 6 months of postseismic deformation and find obvious displacements in the center of the Sadlerochit Mountains. A geological model is proposed to interpret the relationship between this earthquake sequence and the regional structure. We suggest that the 2018 Kaktovik earthquake sequence may first have occurred on a fault unknown prior to the mainshock and triggered slip on both the pre‐existing ramp structure below the Sadlerochit Mountains and a secondary structure.