Having reviewed several time series models, we are now ready for some practical examples. Our first data set is a time series of earthquakes having magnitude that exceeds 4.0 on the Richter scale in Greece over the period between the year 2000 and the year 2008. This data set was recorded by the Observatory of Athens and is hosted on the website of the University of Athens, Faculty of Geology, Department of Geophysics & Geothermics. The data is available online at http://www.geophysics.geol.uoa.gr/catalog/catgr_20002008.epi.

We will import these data directly by using the package RCurl. From this package, we will use the functions getURL(), which retrieves the contents of a particular address on the Internet, and textConnection(), which will interpret the result as raw text. Once we have the data, we provide meaningful names for the columns using information from the website:

> library("RCurl")
> seismic_raw <- read.table(textConnection(getURL(
...