The Epicentral Safari Extension

The epicentral Safari extension installs a small button in your Safari toolbar. Clicking the button opens a new tab in the current Safari browser window that contains a summary of the seismic activity in the last seven days.


How do I install the extension?

You download the file from the link below, then double-click it to install it into the Safari extensions list.

Click here to download the extension

For reference, the file is downloaded into your ~/Library/Safari/Extensions folder (where ~ means you home folder). Safari asks your permission to download the file, then asks if you want to install the extension.  The extension will only work with Safari, not other browsers.

About the global seismicity summary Safari extension

The data for the summary are produced by the US Geological Survey (USGS). The USGS list generally includes all earthquakes with magnitudes of about 5 and larger, and many of the worlds earthquakes with magnitudes of 4.5 and larger. The list also includes information on smaller earthquakes in regions that are more closely monitored by the US scientists, including Alaska, Hawaii, California, Utah, Puerto Rico, the central US (New Madrid) region, and a few other places. The list does not include information on all the small events that occur worldwide.

The summary contains a Google News feed that lists news articles related to earthquakes, a time line display of recent activity showing the week’s events, a world map, a summary of the magnitude distribution of earthquakes, and a table of events. 

The days of the week are indicated along the bottom of the time line - the present time is on the right, the left is roughly seven days ago. The times are in Universal Time Coordinated. Red circles identify events that occurred in the last 12 hrs; orange circles indicate events from 24-to-12 hrs ago, and the yellow circles identify older events. The vertical axis of the time line display identifies magnitude values; the minimum value corresponds to the value that you select in the magnitude-threshold popup menu, each successive line is one magnitude unit larger. The maximum magnitude displayed is 9.5. The magnitude displayed for each earthquake is a summary magnitude listed by the US Geological Survey.

The map presents the same information geographically. The map is centered on the Pacific Ocean region, which hosts most of the world’s seismicity. The table listing the number of events summarizes the information by magnitude with descriptive labels developed originally by Richter, and continually used by the USGS to classify events by size. The event-list table is dynamic, you can sort the information by clicking on the column headings.  Sorting by date will sort the event dates alphabetically (not sort the events by time). To return the table to the state with events sorted by time, click on the ID/Link column.

How do I remove the extension?

You manage extensions in Safari using the Preferences -> Extensions. You can see all your extensions and enable and uninstall any of them from that location.