IRIS Earthquake Browser
The IRIS DMC is pleased to announce the release of a new generation of web based earthquake query tool – the IRIS Earthquake Browser (IEB). The IEB combines the DMC’s large database of earthquakes with the popular Google Maps web interface. The IEB is useful both educationally and as a research tool. With the IEB you can quickly find earthquakes in any region of the globe and then import this information into the GEON Integrated Data Viewer (IDV) where the hypocenters may be visualized in three dimensions.
The GEON IDV is a powerful, free, Java based, desktop application that allows 3D visualization of complex solid earth science data.
The IEB features a simple, yet powerful, user interface. To start using it, you simply zoom and pan a map of the world just as you would with any other Google map. By default, the IEB shows the most recent 200 events in any given view. The number of events shown can be varied from 100 to 5000 while the prioritization of events (which events have priority to be shown) can be toggled between recent events and larger events.
The 1000 largest events from this region are displayed. A distinctive line of deep (red) events are shown on the eastern side of the selection.
Links at the top of the page allow the user to download the data plotted on the map. The data can be viewed as an HTML table or exported as a NetCDF (Network Common Data Form) binary. The exported NetCDF data can then be imported into the GEON IDV.
Online help gives detailed instructions on how to import data from the IEB into the GEON IDV along with other useful information.
The next image is an animation taken from the GEON IDV using the NetCDF data exported from the previous map. The line of deep events is clearly seen as a straight line at depth.
Advanced controls in the IEB allow users to select events by:
- Time Range
- Magnitude Range
- Depth Range
- Magnitude Type
Using these controls can be very informative. For example, constraining event depth ranges from 700 to 900 km shows that the majority of deep events are located near the Tonga trench as shown in the following map (Fig. 3).
Constraining time ranges can be useful in estimating how many events occur in a given region. For example, selecting a region roughly covering the west coast of the United States and selecting the time range 2000-2004 and the magnitude range 3 and greater results in 2033 earthquakes being selected. If the magnitude range is limited to 4 and greater, 124 events are selected.
“Seismo-surfing” around the world can be quite interesting and fun. The following maps show the Mt. St. Helens Volcano in Washington, along with nicely co-located earthquake events (Figs 4 and 5).
How it Works
The earthquake catalogs are provided by USGS/NEIC, ISC and the ANF.
The IEB is part of a new wave of web-service based technology being developed at the IRIS DMC. The IEB makes a large data set quickly and easily available. We would like to give special thanks to UNAVCO’s Stuart Weir for his help in integrating IEB data with the GEON IDV.
Go to the IRIS Earthquake Browser
by Bruce Weertman (IRIS DMC) and Tim Knight (IRIS Data Management Center)