15 September 2007 at
8:50 pm (UTC +8 hours) by Nathaniel Forbes
In addition to the event location and magnitude information described in my previous post, subsequent PTWC bulletins for a particular event also list actual or predicted time and location of impact, and wave heights at specific locations.This is the potentially life-saving information everyone near a coast wants to know after a tsunami warning has been issued: will it hit me, and when?
Locations listed in PTWC bulletins for the southern Sumatra undersea earthquakes last week, for example, include both places (“Padang, Indonesia” in the table below) and ocean monitoring buoys in the region (“DART 23401″ in the table below).
GAUGE LOCATION LAT LON TIME AMPL PER
PADANG IDA 0.9S 100.4E 1348Z 0.98M / 3.2FT 34MIN
DART 23401 8.9S 88.5E 1421Z 0.02M / 0.1FT 15MIN
You can enter or cut-and-paste the latitude and longitude for a place or buoy into Google Earth‘s “Fly To” box. The coordinates “8.9 N 88.5 E” are the location of Deep-Ocean Assessment and Reporting of Tsunamis (DART) buoy 23401, maintained by the Thailand Meteorological Department in the Indian Ocean. This is a global list of buoys.
Indonesia is still struggling to acquire, deploy and maintain buoys off its seismically-active west coast, as this map of current DART buoys regrettably shows. The Asean Earthquake Information Center in Jakarta is a regional information-sharing network that partially compensates for Indonesia’s handicap. Read more... (285 words, 0 images, estimated 1:08 mins reading time)
23 August 2007 at
2:57 pm (UTC +8 hours) by Nathaniel Forbes
I receive email warnings from the U.S. National Oceanographic & Atmospheric Administration (NOAA) Pacific Tsunami Warning Center about earthquakes that might cause tsunami events in the Pacific Rim. The service is fast, free and helpful to emergency response authorities.
Just since late July I’ve received alerts for several earthquakes: two in the South Pacific, two in the Aleutian Islands (Alaska), the big one off the coast of Peru. The PTWC warnings are text-based so they can be received on the lowest common technology denominator, I suppose. The alerts contain no HTML links to the PTWC web site where you could see maps showing the locations of earthquakes.
So I can find it hard to place an event’s latitude and longitude in my mind – “2.7 NORTH 127.5 EAST”, for example. Most people can picture “the coast of Peru,” but I must admit I’m a bit hazy about “North Moluccan Sea.”
Where is that, anyway?
You can find out quickly and simply, and in stunning detail, in Google Earth. Download and install Google Earth (15 megabytes) onto your computer. It’s free. And sign up to receive the PTWC alerts by email. They’re free. too. Then wait for an alert message to show up in your mailbox.
Inside each alert you’ll find data for these parameters: Read more... (479 words, 0 images, estimated 1:55 mins reading time)