[EHPweb] NextGen EQMaps Beta

[Michael Blanpied]

Thanks very much! I appreciate the information.
Extrapolating to even smaller events, it sounds like it may be pretty 
much impossible to locate an event M<0 using network data.

Mike

At 11:31 AM -0800 12/6/10, David Oppenheimer wrote:
>Hi Mike,
>
>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.
>
>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.
>
>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.
>
>-David
>
>From: ehpweb-bounces at geohazards.usgs.gov 
>[mailto:ehpweb-bounces at geohazards.usgs.gov] On Behalf Of Michael 
>Blanpied
>Sent: Friday, December 03, 2010 12:12 PM
>To: Lisa A Wald
>Cc: Leith Bill; EHPweb
>Subject: Re: [EHPweb] NextGen EQMaps Beta
>
>Thanks, Lisa! Sorry to bother you about a resolved issue.
>
>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!
>
>Mike
>
>
>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.
>
>
>
><http://earthquake.usgs.gov/earthquakes/mapping/>http://earthquake.usgs.gov/earthquakes/mapping/
>
>
>
>- Lisa
>
>------
>
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>On Dec 3, 2010, at 12:45 PM, Michael Blanpied wrote:
>
>
>
>Lisa,
>
>
>
>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.
>
>
>
>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.
>
>
>
>Thanks again,
>
>Mike
>
>
>
>At 10:49 AM -0700 12/3/10, Lisa A Wald wrote:
>
>Everyone-
>
>
>
>Thank you for your feedback, comments, and suggestions about the 
>Next Generation Earthquake Maps for the EHP website.
>
>
>
>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.
>
>
>
>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).
>
>
>
>These are some of the tasks we're working on to address your 
>concerns before the Public Beta is launched in January:
>
>
>
>1. Remove clustering algorithm, or allow user to turn it on and off; 
>add cluster symbol to map key.
>
>2. Add links to event pages from event table below map; turn off 
>dbl-click on event symbol on map.
>
>3. Implement full-page-size map.
>
>4. Add magnitude to hover text.
>
>5. Change labeling from "Event" to "Earthquake".
>
>6. Add user guide for features that are not intuitively obvious.
>
>7. Use our own basemaps, cities, list, etc instead of the build-in 
>data provided by Google Maps.
>
>8. Other small changes such as scale bar, lat/lon of mouse position.
>
>
>
>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.
>
>
>
>Thanks for helping to make this an outstanding product!
>
>- Lisa
>--------------------------
>Lisa Wald, Geophysicist
>
>Web Team Manager/Project Manager
>USGS Earthquake Hazards Program
>Golden, CO
>303-273-8543
><mailto:lisa at usgs.gov>lisa at usgs.gov
>
>--------------------------
>
>
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