<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Rus,<div><br></div><div>Another issue is that Seth's quotation implies that the Haiti hazard was mapped using the same techniques as the USGS uses: </div><div> "The same sort of risk evaluation methodology that is used by USGS 'has had a series of spectacular failures around the world in
the last 5 years—Haiti, Wenchuan [China], and Japan,' [Stein] says.</div><div><br></div><div>That is simply not the case, at least in the case of Haiti.</div><div><br></div><div>For Haiti, the only existing hazard map was from GSHAP, which used broad-brush approach to global hazard estimation based on smoothed instrumental seismicity. There was not much hazard mapped in Haiti because the recent seismicity rates have been low. The Enriquillo, Septentrional and other faults were recognized, and it was known that Port au Prince had suffered large pre-instrumental quakes, but these were not taken into account. This was NOT "the same sort of methodology used by USGS."</div><div><br></div><div>Even a back-of-the-envelope calculation taking into account several mm/year on the Enriquillo fault puts a band of high hazard right through the strongly shaken region. Hazard maps based on USGS methods was by Art Frankel, Eric Calais and colleagues, see: <a href="http://pubs.usgs.gov/of/2010/1067/">http://pubs.usgs.gov/of/2010/1067/</a></div><div><br></div><div>What Haiti illustrated was not a failure of modern seismic hazard mapping methods, but that hazard maps for some regions of the world are not up to modern standards. Efforts like Art's and Eric's, and the work of GEM (<a href="http://www.globalquakemodel.org/">http://www.globalquakemodel.org/</a>), are working to improve that situation.</div><div><br></div><div>Mike</div><div><br></div><div><br><div><div>On Apr 27, 2011, at 5:56 PM, Russell L Wheeler wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
<br><font size="2" face="Calibri">Some people may have interpreted the end
of the ScienceNOW article to mean that the USGS hazard evaluation methodology
failed to predict the Haiti, Wenchuan, and Japan earthquakes. The methodology
was not designed to predict the time, size and location of the next big
earthquake, and the USGS does not use it that way.</font>
<br><font size="2" face="Calibri"><br>
The probabilistic methods that the USGS and other organizations use to
estimate hazard are not predictions. Instead, the methods give estimates
of the strength of shaking that we'd expect (at specified odds) to be exceeded
in the next 50 years at some particular place. The specified odds
are usually about one in ten or one in fifty. If a particular place is
shaken at or above the estimated level, the cause could be either a big
earthquake far away, or a smaller one nearby. Also, the expected shaking
could occur at any time from tomorrow to 50 years from now...or not at
all, if it beats the odds. Nothing in a probabilistic hazard estimate specifies
the size, time, and location of the next big earthquake.<br>
<br>
Making a prediction and estimating the hazard are fundamentally different
in purposes, assumptions, calculations, results, and uses. A failure to
get either of them right has no bearing on the validity of the other one.</font><font size="2" face="sans-serif"><br>
-----------------------------------------<br>
Rus Wheeler<br>
research geologist<br>
phone: (303) 273-8589<br>
fax: (303) 273-8600<br>
email: <a href="mailto:wheeler@usgs.gov">wheeler@usgs.gov</a><br>
<br>
paper mail:<br>
Russell L. Wheeler<br>
U.S. Geological Survey<br>
P.O. Box 25046, M.S. 966<br>
Lakewood, CO 80225<br>
<br>
physical address, FedEx, UPS:<br>
1711 Illinois St., rm. 442<br>
Golden, CO 80401</font>
<br>
<br>
<br>
<table width="100%">
<tbody><tr valign="top">
<td><font size="1" color="#5f5f5f" face="sans-serif">From:</font>
</td><td><font size="1" face="sans-serif">Oliver Boyd <<a href="mailto:olboyd@usgs.gov">olboyd@usgs.gov</a>></font>
</td></tr><tr valign="top">
<td><font size="1" color="#5f5f5f" face="sans-serif">To:</font>
</td><td><font size="1" face="sans-serif">"<a href="mailto:ceus-earthquake-hazards@geohazards.usgs.gov">ceus-earthquake-hazards@geohazards.usgs.gov</a>"
<<a href="mailto:ceus-earthquake-hazards@geohazards.usgs.gov">ceus-earthquake-hazards@geohazards.usgs.gov</a>></font>
</td></tr><tr valign="top">
<td><font size="1" color="#5f5f5f" face="sans-serif">Date:</font>
</td><td><font size="1" face="sans-serif">04/27/2011 10:09 AM</font>
</td></tr><tr valign="top">
<td><font size="1" color="#5f5f5f" face="sans-serif">Subject:</font>
</td><td><font size="1" face="sans-serif">[CEUS-earthquake-hazards] Article on
Central U.S. Earthquake hazard by expert
panel</font>
</td></tr><tr valign="top">
<td><font size="1" color="#5f5f5f" face="sans-serif">Sent by:</font>
</td><td><font size="1" face="sans-serif"><a href="mailto:ceus-earthquake-hazards-bounces@geohazards.usgs.gov">ceus-earthquake-hazards-bounces@geohazards.usgs.gov</a></font></td></tr></tbody></table>
<br>
<hr noshade="">
<br>
<br>
<br><font size="2" face="Calibri">Dear CEUS earthquake hazards email list
subscribers,<br>
Below is a link to a short article about the findings of a National Earthquake
Prediction Evaluation Council expert panel regarding central United States
earthquake hazard.<br>
</font><font size="2" color="blue" face="Calibri"><u><br>
</u></font><a href="http://news.sciencemag.org/sciencenow/2011/04/expert-panel-central-us-faces.html"><font size="2" color="blue" face="Calibri"><u>http://news.sciencemag.org/sciencenow/2011/04/expert-panel-central-us-faces.html</u></font></a><font size="2" face="Calibri"><br>
<br>
Regards,<br>
Oliver<br>
<br>
-- <br>
<br>
Oliver Boyd, Ph.D.<br>
Research Geophysicist<br>
U.S. Geological Survey<br>
3876 Central Ave<br>
Memphis, TN<br>
Phone: (901) 678-3463<br>
FAX: (901) 678-4897</font><tt><font size="2">_______________________________________________<br>
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<a href="mailto:CEUS-Earthquake-Hazards@geohazards.usgs.gov">CEUS-Earthquake-Hazards@geohazards.usgs.gov</a><br>
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