Wednesday, July 11, 2007

Tsunami Warning System communication test shows Indian Ocean problem

The Pacific Tsunami Warning Center (part of the US NOAA, based in Hawaii) conducted a communications test on 11 July 2007. This showed a possible problem with the Indian Ocean system.
This is a test to verify communication links and determine transmission times involved in the dissemination of operational tsunami advice products from the pacific tsunami warning center to designated 24-hour tsunami warning focal points of the pacific tsunami warning system. ...

The official addressees were asked to report back how and when the message was received. The centre will then calculate the transmission time. Messages are sent by fax and email, as well as several specialized networks: Global Telecommunications System (GTS), Aeronautical Fixed Telecommunication Network (AFTN) , Emergency Managers Weather Information Network (EMWIN), and Ranet.

The official recipients are designated 24-hour emergency centers in countries of the Pacific region. The message was also forwarded by the interim Indian Ocean warning system sponsored by UNESCO.

While not part of the official test, receipt on my system indicated:

PTWC1:53:39 2:19:44
Spam Filter2:19:46
Local Host2:19:51

This indicates there was a twenty six minute delay in the UNESCO system forwarding the message to the Indian Ocean network. Also there are six seconds delay within the local host machine, mostly due to the spam filtering. As I previously noted there is also a risk the message may not be received at all due to spam filters.

Low Tsunami Warning StatusThe PTWC have also instituted a colour coded four level system for grading tsunami warnings, with green, yellow, amber and red, indicating the increasing severity. A dial with pointer (similar to Australian bushfire Fire Danger Meters) is used to indicate the severity on the colored scale. This is useful for those who are unable to perceive color. However, there are no text equivalents for the colors and the text description are incomplete and ambiguous.

The description says: "Colors correspond to the message severity (red=most, green=least)". However, the other two levels are not mentioned. Also the text descriptions "most" and "least" do not match those used to label the corresponding dial images: "low", "moderate", "high", and "severe". In addition the levels on the description page are in the reverse order (high to low) to those on the indicator dial (low to high), which is confusing. Also those less familiar with English will have difficulty distinguishing which is higher priority:
"high" or "severe".

PTWC should list all four severity levels in order of severity on the description page and include standard text captions. The same text captions should be used adjacent to the dial on warning pages for those who cannot see the images (as the ACT
Emergency Services Agency does for bush fires). PTWC should also consider including a numeric ranking from 1 to 4.

1LowGreenLow Tsunami Warning Status
2ModerateYellowModerate Tsunami Warning Status
3HighAmberHigh Tsunami Warning Status
4SevereRedSevere Tsunami Warning Status

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