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Implications of the October 1995 Colima‐Jalisco Mexico earthquakes on the Rivera—North America Euler vector
Author(s) -
Bandy W.,
Kostoglodov V.,
Singh S. K.,
Pardo M.,
Pacheco J.,
UrrutiaFucugauchi J.
Publication year - 1997
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 - 10.1029/97gl00176
Subject(s) - seismology , aftershock , geology , slip (aerodynamics) , seismic moment , geodesy , euler's rotation theorem , euler's formula , focal mechanism , convergence (economics) , induced seismicity , plate tectonics , tectonics , fault (geology) , geometry , physics , mathematics , mathematical analysis , rotation (mathematics) , thermodynamics , economic growth , economics
Rivera‐North America Euler vectors fall into three groups based on the predicted motion of the Rivera plate relative to the North America plate along the Middle America Trench north of 18.5°N. Namely, those that predict (1) a slow, more easterly directed motion, (2) a slow, more northerly directed motion, and (3) a faster, more northerly directed motion. The focal mechanism solution, rupture area and seismic moment of the great (M w =8.0) Colima‐Jalisco, Mexico, earthquake of October 9, 1995 and its foreshocks and aftershocks provide additional constraints on the Rivera‐North America Euler vector. The slip direction (N30°E) of the main event clearly favors those Euler poles which predict a more northerly direction of motion. This direction lies within 5° of those predicted by these poles, whereas, it differs by between 9° and 18° from those poles which predict a more easterly motion. The amount of slip which occurred during the main event suggests a minimum convergence rate of between 4.3 and 6.5 cm/yr. This favors Euler vectors which predict higher convergence rates, however, a firm conclusion cannot be made due to the uncertainty in the recurrence time estimation. A new Rivera‐North America Euler pole, calculated incorporating the information provided by the 1995 events, lies at 21.87°N, 109.58°W. It predicts a N30.3°E directed motion of the Rivera plate relative to North America at the location of the main event; a difference of only 0.3° from the slip direction of the main event.