Earthquake Environmental Effects in Colombia during the Past 35 Years: INQUA Scale Project

Abstract

In this work we present the results of applying the inqua intensity scale to the analysis of the environmental effects of 12 moderate-to-large earthquakes with moment magnitudes ( M w ) in the range 5.6–8.1 that shook Colombia between 1970 and 2004. These earthquakes were selected following consideration of their depths, magnitudes, and relevance of effects during shaking. After analysis of shaking effects, we found that earthquakes in Colombia could be assigned inqua intensities between 6 and 11. For a subgroup of seven earthquakes, we found a positive correlation between inqua intensities and M w defined by a best-fit linear trend with a correlation coefficient of 0.7 and a positive correlation between inqua intensities and Modified Mercalli intensities with a correlation coefficient of 0.6. The inqua scale allowed us to compare local earthquakes with other earthquakes worldwide and to analyze each earthquake to better understand the ground response in Colombia to the shaking during shallow earthquakes. We conclude that, in general, the inqua scale provides a good estimate of intensity that may complement other measures of intensity.