# Retrieve seismic traveltime information from EarthScope The `getTraveltime` method obtains seismic traveltime data from the EarthScope `traveltime` web service and returns it in a dataframe. methods ```r getTraveltime(obj, latitude, longitude, depth, staLatitude, staLongitude) ``` ## Arguments - `obj`: an `IrisClient` object - `latitude`: latitude of seismic event - `longitude`: longitude of seismic event - `depth`: depth of seismic event - `staLatitude`: latitude of seismic station - `staLongitude`: longitude of seismic station ## Details The `traveltime` web service calculates travel-times for seismic phases using a 1-D spherical earth model. ## Returns A dataframe with the following columns: ``` distance, depth, phaseName, travelTime, rayParam, takeoff, incident puristDistance, puristName ``` Rows are ordered by `travelTime`. ## References The EarthScope traveltime web service: [https://service.earthscope.org/irisws/traveltime/1/](https://service.earthscope.org/irisws/traveltime/1/) ## Author(s) Jonathan Callahan jonathan@mazamascience.com ## See Also `IrisClient-class` ## Examples ```r ## Not run: # Open a connection to EarthScope webservices iris <- new("IrisClient") # Two days around the "Nisqually Quake" starttime <- as.POSIXct("2001-02-27", tz="GMT") endtime <- starttime + 3600 * 24 * 2 # Find biggest seismic event over these two days -- it's the "Nisqually" events <- getEvent(iris, starttime, endtime, minmag=5.0) bigOneIndex <- which(events$magnitude == max(events$magnitude)) bigOne <- events[bigOneIndex[1],] # Find US stations that are available within an hour of the event start <- bigOne$time end <- start + 3600 availability <- getAvailability(iris, "US", "", "", "BHZ", starttime=start, endtime=end, latitude=bigOne$latitude, longitude=bigOne$longitude, minradius=0, maxradius=10) # Get the station the furthest East minLonIndex <- which(availability$longitude == max(availability$longitude)) snclE <- availability[minLonIndex,] # Plot the BHZ signal from this station st <- getDataselect(iris,snclE$network,snclE$station,snclE$location,snclE$channel, start,end) # Check that there is only a single trace and then plot it length(st@traces) tr <- st@traces[[1]] plot(tr, subsampling=1) # need subsmpling=1 to add vertical lines with abline() # Find travel times to this station traveltimes <- getTraveltime(iris, bigOne$latitude, bigOne$longitude, bigOne$depth, snclE$latitude, snclE$longitude) # Look at the list traveltimes # mark the P and S arrival times pArrival <- start + traveltimes$travelTime[traveltimes$phaseName=="P"] sArrival <- start + traveltimes$travelTime[traveltimes$phaseName=="S"] abline(v=pArrival, col='red') abline(v=sArrival, col='blue') ## End(Not run) ```

getTraveltime function