Charles Francis Richter and Beno Gutenberg, in 1944, found some interesting empirical statistics about earthquakes. It was about how the magnitude of earthquakes related to their frequencies. Today, we revisit the topics using data downloaded from ANSS Composite Catalog (364,368 data from 1900 – 2012).
A histogram of the magnitude is below.
The next step is to generate annual frequency from this. Since the data is from 1900-2012, we will divide the frequency by 112 to get the desired parameter. The following R codes provide the steps till the plot is generated. Note that the Y-axis is in the log scale.
quake_data <- read.csv("./earth_quake.csv")
hist_quake <- hist(quake_data$Magnitude, breaks = 50)
plot(hist_quake$mids, (hist_quake$counts/112), log='y', ylim = c(0.001,1000), xlab = "Magnitude", ylab = "Annual frequency")
Add an extra line to make a linear fit.
abline(lm(log10(hist_quake$counts/112) ~ hist_quake$mids), col = "red", lty = 2, lwd = 3)
