[Aust-NZ] better chch earthquake map

[Hamish]

[cc nzOpenGIS google group]

Hi,

unhappy with the thrown-together/not very helpful google earth
graphics on the news, linear-scale bubble plots available
elsewhere[1], already doing something similar for regional NZ and the
rest of the world[2,3] using GNS and USGS data feeds, and hungry for
info, I decided that it wouldn't be too hard to put together a bit
clearer picture,

see  http://adhoc.osgeo.osuosl.org/grass/New_Zealand/earthquakes_NZ_ChCh.png

--to catch any aftershocks that image updates every 15 minutes right now.

a companion ChCh KMZ file is coming soon. (broken right now due to a
pesky OGR bug mixing lat/lon with NZTM (it works using an older
version, and the USGS lat/lon-only version in the parent directory is
ok...)), but probably GNS has a nice KML available for download
already, so just reinventing/reprocessing the wheel with that.


[1] magnitude energy actually goes something like Energy_petajoules =
( 10^(11.8 + 1.5*Ms) ) * 1e-07 * 1e-15, which is very very very far
from linear. I've toned that down a bit so the rings actually fit on
the screen, but it's a whole lot more realistic than having 4.0's be
a quarter the size of 6.0's.
[2] http://adhoc.osgeo.osuosl.org/grass/alternate_projections/earthquakes_wintri.png
[3] http://adhoc.osgeo.osuosl.org/grass/New_Zealand/earthquakes_NZ_lcc.png
 (still need to zoom that properly)

-the scripts to do all this with free software+data are available in
the GRASS GIS tutorials svn, I'll add the chch script there tomorrow.
-backdrop is historic LANDSAT from NASA's OnEarth global mosaic WMS.
-the ring-size legend image on the server for the global plot (parent
dir) only applies to the global maps.


best,
Hamish