IRISSeismic (version 1.0.5)

getEvent: Retrieve seismic event information from IRIS DMC

Description

The getEvent method obtains seismic event data from the IRIS DMC event webservice.

Usage

getEvent(obj, starttime, endtime, minmag, maxmag, magtype,
         mindepth, maxdepth)

Arguments

obj

an IrisClient object

starttime

POSIXct class limiting results to events occurring after starttime (GMT)

endtime

POSIXct class limiting results to events occurring before endtime (GMT)

minmag

optional minimum magnitude

maxmag

optional maximum magnitude

magtype

optional magnitude type

mindepth

optional minimum depth (km)

maxdepth

optional maximum depth (km)

Value

• A dataframe with the following columns:

  eventId ,time, latitude, longitude, depth, author, cCatalog, contributor, contributorId, magType, magnitude, magAuthor, eventLocationName

  Rows are ordered by time.

  NOTE: column names are identical to the names returned from the event web service with the exception of "latitude" for "lat" and "longitude" for "lon". The longer names are used for internal consistency -- all other web services return columns named "latitude" and "longitude".

Details

The getEvent method uses the event web service to obtain data for all events that meet the criteria defined by the arguments and returns that data in a dataframe. Each row of the dataframe represents a unique event.

References

The IRIS DMC event webservice:

http://service.iris.edu/fdsnws/event/1/

See Also

IrisClient-class,

Examples

# NOTE:  'maps' and 'mapdata' packages must be installed
require(maps)
require(mapdata)

# Open a connection to IRIS DMC webservices
iris <- new("IrisClient")

# Get events > mag 5.0 over a week in June of 2012
starttime <- as.POSIXct("2012-06-21", tz="GMT")
endtime <- starttime + 3600 * 24 * 7
events <- getEvent(iris, starttime, endtime, minmag=5.0)

# Look at all events
print(paste(nrow(events),"earthquakes found with magnitude > 5.0"))
  
# Plot events on a map
map('world')
points(events$longitude, events$latitude, pch=16, cex=1.5, col='red')
labels <- paste(" ", as.character(round(events$magnitude,1)), sep="")
text(events$longitude, events$latitude, labels=labels, pos=4, cex=1.2, col='red3')