<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I'll restate the comment I added on the Science page after Richard Kerr's article:<div><br></div><div><span class="Apple-style-span" style="font-family: 'Lucida grande', Tahoma, Verdana, Arial; color: rgb(58, 58, 58); font-size: 11px; line-height: 16px; ">It's not clear to me why the spectacula<wbr>r earthquake<wbr>s in Haiti, China, New Zealand or Japan would bode ill for the USGS way of estimating hazard, nor motivate zeroing the New Madrid Seismic Zone hazard. <br> <br>Using the current USGS methodolog<wbr>y, the rates of activity geological<wbr>ly visible on the Haiti and Chinese faults would lead to a decent estimates of the hazard, and would have even before the earthquake<wbr>s had occurred. While the magnitude of the Japanese earthquake was a surprise in its contrast to the local hazard estimate, the USGS invokes more comprehens<wbr>ive logic trees in California and elsewhere that could well have captured some component of the compound-s<wbr>egment hazard in Japan. <br> <br>It's true by definition that very rare earthquake<wbr>s, such as those in China, New Zealand, and Japan that had recurrence intervals of upwards of a thousand years, are unlikely. Those low-freque<wbr>ncy faults shouldn't appear as hotspots on hazard maps, even though they make up a substantia<wbr>l fraction of ongoing activity. I agree probably hazard maps should be smoother, maybe that's Seth's only point. <br> <br>However, the history of repeated large earthquake<wbr>s in New Madrid earthquake<wbr>s is not well enough understood to lower our guard just yet. If anything, the lesson of surprising earthquake<wbr>s is that we should not write off threats that we do not yet understand<wbr>.</span><br></div><div><span class="Apple-style-span" style="font-family: 'Lucida grande', Tahoma, Verdana, Arial; color: rgb(58, 58, 58); font-size: 11px; line-height: 16px; "><br></span></div><div><span class="Apple-style-span" style="font-family: 'Lucida grande', Tahoma, Verdana, Arial; color: rgb(58, 58, 58); font-size: 11px; line-height: 16px; ">John</span></div></body></html>