Click for high-res map
Software: Apache, PHP5, GRASS 6 (see here for PHP4 example; here for GRASS location with world map)
What happens here?
The server is fetching the current list of earthquakes from
http://neic.usgs.gov/neis/gis/bulletin.asc
and generates a vector map with attributes from that. The result is overlayed to the
Blue Marble Next Generation map from May.
//
// Home: http://grass.itc.it/spearfish/php_grass_earthquakes.php
//
// Inspired by:
// http://grass.itc.it/pipermail/grass5/2004-August/015106.html
//
// Possible improvements:
// - use PHP session to avoid race conditions
// (use session name as mapset etc)
// - replace calls by GRASS-SWIG-PHP interface
// Approach:
// GRASS is simply a set of commands which need to be run in
// a pre-defined environment. A map is generated as PNG file
// and then visualized.
// To keep it simple, we use system commands. Note the trailing
// semicolon for each command, otherwise it won't work.
// Prerequisites:
// Add 'MONITOR: PNG' to the .grassrc6 file (see GISRC below).
// Update also the path to the location. The GRASS location needs to be
// recursively set to the owner/group of Web server (e.g. 'apache' user/group)
// as the Web server software launches GRASS. Check for access permissions
// also in the parent directories.
// Also this directory where the files/map is generated, needs to
// be owned by the Web server user.
//
// ---------------------
// Here we go:
// 1. define the environment settings (full path everywhere):
$descriptorspec = array(
0 => array("pipe", "r"), // stdin is a pipe that the child will read from
1 => array("pipe", "w"), // stdout is a pipe that the child will write to
2 => array("pipe", "w") // stderr is a file to write to
);
$cwd = '.';
// define environment variables
$env = array(
'GISBASE' => '/usr/local/grass-6.1.cvs',
'PATH' => '/bin:/usr/bin:/usr/local/bin:/usr/local/grass-6.1.cvs/bin:/usr/local/grass-6.1.cvs/scripts',
// WARNING: probably protected in /etc/php.ini (see 'safe_mode_protected_env_vars')
'LD_LIBRARY_PATH' => '/lib:/usr/lib:/usr/local/grass-6.1.cvs/lib',
// note that the GRASS location needs owner/group of Web server (e.g. 'apache' user/group)
'GISRC' => '/krokus0/www/grass/html/spearfish/.grassrc6_ll',
// also the output files need owner/group of Web server:
'GRASS_PNGFILE' => 'earthquakes.png',
'GRASS_TRUECOLOR' => 'TRUE',
'GRASS_WIDTH' => '900',
'GRASS_PNG_COMPRESSION' => '1',
'HOME' => '/tmp',
// better use posix_getpid();
'GIS_LOCK' => '$$'
);
// 3. fetch & polish earthquake data
// GRASS session....
// watch out for quotes-in-quotes in SQL commands and $:
$command = "
lynx -dump http://neic.usgs.gov/neis/gis/bulletin.asc > /tmp/bulletin.tmp;
cat /tmp/bulletin.tmp | sed 's+ ++g' | grep -v ',,' | grep -v '^$' > bulletin.asc;
env > environment_vars2.txt;
rm -f grasserrors2.txt grassmsgs2.txt;
echo \$LD_LIBRARY_PATH >> grasserrors2.txt;
echo \$PATH >> grasserrors2.txt;
echo \$GISBASE >> grasserrors2.txt;
echo \$GISRC >> grasserrors2.txt;
echo \$GIS_LOCK >> grasserrors2.txt;
g.region -d >> grasserrors2.txt;
d.mon PNG 2>> grasserrors2.txt;
cat bulletin.asc | v.in.ascii out=recent_earthquakes skip=1 fs=',' y=3 x=4 col='e_date date, e_time varchar(10), lat double precision, long double precision, magnitude double precision, depth double precision' --o >> grassmsgs2.txt 2>> grasserrors2.txt;
v.db.addcol recent_earthquakes col='class integer' ;
v.db.update recent_earthquakes col=class value=1 where='magnitude < 3' ;
v.db.update recent_earthquakes col=class value=2 where='magnitude >=3 AND magnitude < 4' ;
v.db.update recent_earthquakes col=class value=3 where='magnitude >=4 AND magnitude < 5' ;
v.db.update recent_earthquakes col=class value=4 where='magnitude >=5 AND magnitude < 6' ;
v.db.update recent_earthquakes col=class value=5 where='magnitude >=6 AND magnitude < 7' ;
v.db.update recent_earthquakes col=class value=6 where='magnitude >=8' ;
# center at Pacific
g.region w=-18 e=-18
d.rast BMNG_May.rgb >> grassmsgs2.txt 2>> grasserrors2.txt;
echo '' ;
d.vect.thematic recent_earthquakes column=class type=point themetype=graduated_points maxsize=20 nint=6 >> grassmsgs2.txt >> grassmsgs2.txt 2>> grasserrors2.txt;
echo '
' ;
d.mon stop=PNG >> grassmsgs2.txt 2>> grasserrors2.txt;
g.remove vect=recent_earthquakes >> grassmsgs2.txt 2>> grasserrors2.txt;
\$GISBASE/etc/clean_temp
rm -rf /tmp/grass6-\$USER-\$GIS_LOCK
rm -f earthquakes_small.jpg ;
convert -geometry 75% earthquakes.png earthquakes_small.jpg;
convert -geometry 40% earthquakes.png earthquakes_tiny.jpg;
"; // command
$process = proc_open($command, $descriptorspec, $pipes, $cwd, $env);
if (is_resource($process)) {
// $pipes now looks like this:
// 0 => writeable handle connected to child stdin
// 1 => readable handle connected to child stdout
// 2 => readable handle connected to child stderr
fwrite($pipes[0], '');
fclose($pipes[0]);
echo stream_get_contents($pipes[1]);
fclose($pipes[1]);
echo stream_get_contents($pipes[2]);
fclose($pipes[2]);
$return_value = proc_close($process);
//echo $return_value;
}
?>
Earthquake classification (circles in map are sized by these classes)
| Magnitude | Classification | Class for map |
| 0 - 3 | Micro | 1 |
| 3 - 3.9 | Minor | 2 |
| 4 - 4.9 | Light | 3 |
| 5 - 5.9 | Moderate | 4 |
| 6 - 6.9 | Strong | 5 |
| 7 - 7.9 | Major | 6 |
| 8 and higher | Great | 7 |
Here a map should appear:
Oldest event from:
UTC ; Latest event from:
UTC
Latest events drawn last.
Click for high-res map
For earthquake details, visit Latest Earthquakes in the World - Last 7 days from USGS.