@article{fdi:010049529,
  title = {{L}ocations and magnitudes of historical earthquakes in the {S}ierra of {E}cuador (1587-1996)},
  author = {{B}eauval, {C}{\'e}line and {Y}epes, {H}. and {B}akun, {W}.{H}. and {E}gred, {J}. and {A}lvarado, {A}. and {S}ingaucho, {J}.{C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}>{T}he whole territory of {E}cuador is exposed to seismic hazard. {G}reat earthquakes can occur in the subduction zone (e.g. {E}smeraldas, 1906, {M}-w 8.8), whereas lower magnitude but shallower and potentially more destructive earthquakes can occur in the highlands. {T}his study focuses on the historical crustal earthquakes of the {A}ndean {C}ordillera. {S}everal large cities are located in the {I}nterandean {V}alley, among them {Q}uito, the capital (similar to 2.5 millions inhabitants). {A} total population of similar to 6 millions inhabitants currently live in the highlands, raising the seismic risk. {A}t present, precise instrumental data for the {E}cuadorian territory is not available for periods earlier than 1990 (beginning date of the revised instrumental {E}cuadorian seismic catalogue); therefore historical data are of utmost importance for assessing seismic hazard. {I}n this study, the {B}akun & {W}entworth method is applied in order to determine magnitudes, locations, and associated uncertainties for historical earthquakes of the {S}ierra over the period 1587-1976. {A}n intensity-magnitude equation is derived from the four most reliable instrumental earthquakes ({M}-w between 5.3 and 7.1). {I}ntensity data available per historical earthquake vary between 10 ({Q}uito, 1587, {I}ntensity >= {VI}) and 117 ({R}iobamba, 1797, {I}ntensity >= {III}). {T}he bootstrap resampling technique is coupled to the {B}&{W} method for deriving geographical confidence contours for the intensity centre depending on the data set of each earthquake, as well as confidence intervals for the magnitude. {T}he extension of the area delineating the intensity centre location at the 67 per cent confidence level (+/- 1 {S}igma) depends on the amount of intensity data, on their internal coherence, on the number of intensity degrees available, and on their spatial distribution. {S}pecial attention is dedicated to the few earthquakes described by intensities reaching {IX}, {X} and {XI} degrees. {T}wenty-five events are studied, and nineteen new epicentral locations are obtained, yielding equivalent moment magnitudes between 5.0 and 7.6. {L}arge earthquakes seem to be related to strike slip faults between the {N}orth {A}ndean {B}lock and stable {S}outh {A}merica to the east, while moderate earthquakes ({M}-w < 6) seem to be associated with to thrust faults located on the western internal slopes of the {I}nterandean {V}alley.},
  keywords = {{S}eismicity and tectonics ; {S}eismic attenuation ; {S}outh {A}merica},
  booktitle = {},
  journal = {{G}eophysical {J}ournal {I}nternational},
  volume = {181},
  numero = {3},
  pages = {1613--1633},
  ISSN = {0956-540{X}},
  year = {2010},
  DOI = {10.1111/j.1365-246{X}.2010.04569.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049529},
}