Sunday, January 4, 2009

NEIC post on Lancaster earthquake

The U.S. Geological Survey's Earthquake Hazards Program (aka National Earthquake Information Center) web pages have great information on earthquakes. Let's look at the information provided for the recent Lancaster earthquake.

First, the basics, to be found here, or copied below:

(click above for a larger image)

Obviously, this page gives the basic hypocenter or focus, epicenter, and magnitude information on the quake: where, when, how deep, how big, what cities was it close to (where damage might have occurred), and indicators of uncertainty and reliability. Meanings of the terms are given here; note the different types of magnitudes, perhaps the source for a future blog.

1 comment:

  1. Charles ScharnbergerJanuary 5, 2009 at 2:17 PM

    Note that the error estimate on the epicenter location is +/- 4.5 km. This information generally is lost on the news media, who want to take a photograph or video footage of the EXACT spot. I small pet peeve of mine is that the USGS routinely gives epicenter locations to a precision of 0.001 degree, which is about 100 meters, when the error is several kilometers!


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