Earthquakes Over the Past 7 Days

This is a brief example using the maps in R and to highlight a source of data.  This is real-time data and it comes from the U.S. Geological Survey.  This shows the location of earthquakes with magnitude of at least 1.0 in the lower 48 states.

```
library(maps)
library(maptools)
library(rgdal)

plot.new()
my.map <- map("state", interior = FALSE, plot=F)
x.lim <- my.map\$range[1:2]; x.lim[1] <- x.lim[1]-1; x.lim[2] <- x.lim[2]+1;
y.lim <- my.map\$range[3:4]; y.lim[1] <- y.lim[1]-1; y.lim[2] <- y.lim[2]+1;
map("state", interior = FALSE, xlim=x.lim, ylim=y.lim)
map("state", boundary = FALSE, col="gray", add = TRUE)
title("Magnitude 1+ Earthquakes Over the Past 7 Days")

eq\$mag.size <- NULL
eq\$mag.size[eq\$Magnitude>=1 & eq\$Magnitude<2] <- .75
eq\$mag.size[eq\$Magnitude>=2 & eq\$Magnitude<3] <- 1.0
eq\$mag.size[eq\$Magnitude>=3 & eq\$Magnitude<4] <- 1.5
eq\$mag.size[eq\$Magnitude>=4] <- 2.0

eq\$mag.col <- NULL
eq\$mag.col[eq\$Magnitude>=1 & eq\$Magnitude<2] <- 'blue'
eq\$mag.col[eq\$Magnitude>=2 & eq\$Magnitude<3] <- 'green'
eq\$mag.col[eq\$Magnitude>=3 & eq\$Magnitude<4] <- 'orange'
eq\$mag.col[eq\$Magnitude>=4] <- 'red'

points(x=eq\$Lon,y=eq\$Lat,pch=16,cex=eq\$mag.size, col=eq\$mag.col)
eq\$magnitude.text <- eq\$Magnitude
eq\$magnitude.text[eq\$Magnitude<4] <- NA

legend('bottomright',c('M 1-2','M 2-3','M 3-4','M4+'), ncol=2,
pch=16, col=c('blue','green','orange','red'))
box()

```

1. Matthew Stromberg

/  November 30, 2012

Very, very cool stuff. I was playing with your code to look at sales numbers at my company and visualization is definitely more insightly than State groupings. Thank you for sharing!

2. pssguy

/  December 4, 2012

Thanks for this
You may be interested in a work in progress Shiny app I produced based on your work

associated blog post

• Wesley

/  December 5, 2012

That’s great that the post inspired your very cool app. Thanks.

3. Vitor Chagas

/  August 10, 2013

Just found your post, it inspired me to create my own post.

my post