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--></style><title>RE: [EHPweb] NextGen EQMaps
Beta</title></head><body>
<div>Thanks very much! I appreciate the information.</div>
<div>Extrapolating to even smaller events, it sounds like it may be
pretty much impossible to locate an event M<0 using network
data.</div>
<div><br></div>
<div>Mike</div>
<div><br></div>
<div>At 11:31 AM -0800 12/6/10, David Oppenheimer wrote:</div>
<blockquote type="cite" cite>Hi Mike,</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>The M<1 quake-issue arose with respect
to Parkfield and Long Valley, where the borehole networks enable us to
detect/locate quakes much smaller than 1.0. The same is true at the
Geysers where the 23-station Calpine network drives the detection
threshold down. The problem is that the coda duration (Md) algorithm
used in Earthworm (and AQMS) discards codas <7s because in the
previous analog world these short codas would generally be noise
glitches. So, M<1 quakes generally have indeterminate magnitudes.
Still, even with a "zero" magnitude, the P.I.'s monitoring these
areas what to see the smaller quakes on the recenteqs
pages.</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>Now that the NCSN has complete metadata
for all digital waveforms back to 1984, we can determine if the record
is not clipped and, if so, compute synthetic Wood Anderson seismograms
for all quakes - even those recorded by analog equipment. We can
then calculate the peak amplitudes for use in determining ML for these
small quakes.</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>We're in the discussion stages of how
to do this. It will take a lot of computation and careful calibration
to get the Ml scale correct for M<3 quakes where the traditional ML
scale was developed.</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>-David</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite><b>From:</b>
ehpweb-bounces@geohazards.usgs.gov
[mailto:ehpweb-bounces@geohazards.usgs.gov]<b> On Behalf Of</b>
Michael Blanpied<br>
<b>Sent:</b> Friday, December 03, 2010 12:12 PM<br>
<b>To:</b> Lisa A Wald<br>
<b>Cc:</b> Leith Bill; EHPweb<br>
<b>Subject:</b> Re: [EHPweb] NextGen EQMaps Beta</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>Thanks, Lisa! Sorry to bother you about a
resolved issue.</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>So the floor is now M=0? I assume that
will satisfy folks. I actually have no idea whether the network
locates earthquakes M<0!</blockquote>
<blockquote type="cite" cite> </blockquote>
<blockquote type="cite" cite>Mike</blockquote>
<blockquote type="cite" cite> <br>
<blockquote>The omission of M<1 earthquakes was an error on our
part. We fixed that one immediately. If you take a look at
the Beta maps now, you'll see all the M<1 earthquakes on them
already.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote><a
href="http://earthquake.usgs.gov/earthquakes/mapping/"
>http://earthquake.usgs.gov/earthquakes/mapping/</a><br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>- Lisa<br>
</blockquote>
<blockquote>------<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>On Dec 3, 2010, at 12:45 PM, Michael Blanpied wrote:<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>Lisa,<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>Thanks very much for the feedback and summary! It's great
to know that you're making progress on the new maps, and that you've
found a suitable way around the Google impediments.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>One point that I don't see on your list is the question of
M<1 earthquakes. Our colleagues with interests in central
California and in volcanic areas are very keen to see the magnitude
floor removed from the maps. This has been brought to my attention a
couple of times now, so I'd appreciate hearing the status of that
issue so that I'll know how to respond next time it comes up.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>Thanks again,<br>
</blockquote>
<blockquote>Mike<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>At 10:49 AM -0700 12/3/10, Lisa A Wald wrote:<br>
</blockquote>
<blockquote>Everyone-<br>
<blockquote> <br>
</blockquote>
<blockquote>Thank you for your feedback, comments, and suggestions
about the Next Generation Earthquake Maps for the EHP website.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>The Web Team has compiled the various comments, weighted
them according to how many times we received the same comment, and we
are currently addressing all the comments starting with those with the
highest priority.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>Because of Google licensing issues with our high web
traffic to the EQ Maps, we are having to move to another client-side
software, OpenLayers API. I think you'll agree that OpenLayers
is every bit as good, if not better, than Google Maps (and it doesn't
preclude us from using Google Maps API in the future if the licensing
issue is resolved).<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>These are some of the tasks we're working on to address
your concerns before the Public Beta is launched in January:<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>1. Remove clustering algorithm, or allow user to turn it
on and off; add cluster symbol to map key.<br>
</blockquote>
<blockquote>2. Add links to event pages from event table below map;
turn off dbl-click on event symbol on map.</blockquote>
<blockquote><br></blockquote>
<blockquote>3. Implement full-page-size map.<br>
</blockquote>
<blockquote>4. Add magnitude to hover text.<br>
</blockquote>
<blockquote>5. Change labeling from "Event" to
"Earthquake".<br>
</blockquote>
<blockquote>6. Add user guide for features that are not intuitively
obvious.<br>
</blockquote>
<blockquote>7. Use our own basemaps, cities, list, etc instead of the
build-in data provided by Google Maps.<br>
</blockquote>
<blockquote>8. Other small changes such as scale bar, lat/lon of mouse
position.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>Additional features, such as faults with mouse-over info,
volcano locations, caldera boundaries, etc. will be added in the
future, potentially before the final public release. We'll have
a mechanism in place to receive comments on the next beta version
too.<br>
</blockquote>
<blockquote> <br>
</blockquote>
<blockquote>Thanks for helping to make this an outstanding
product!<br>
</blockquote>
<blockquote>- Lisa<br>
--------------------------<br>
Lisa Wald, Geophysicist<br>
</blockquote>
<blockquote>Web Team Manager/Project Manager<br>
USGS Earthquake Hazards Program<br>
Golden, CO<br>
303-273-8543<br>
<a href="mailto:lisa@usgs.gov">lisa@usgs.gov</a><br>
</blockquote>
<blockquote>--------------------------<br>
</blockquote>
</blockquote>
</blockquote>
<blockquote type="cite" cite> </blockquote>
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