HAMNET Report 15th October 2023

Well, Tropical Cyclone KOINU still isn’t off the map. In spite of the original forecast that it would affect the Chinese coastline only, KOINU has dumped large amounts of rain over Taiwan, Northern Philippines, and Southern Japan. As of Wednesday, 3.7 million people were still in its path.

And a new one has developed off the Pacific coast of Mexico, travelling towards Mexico, called LIDIA, with maximum forecast wind speeds of 167km/h, and threatening 842 thousand people in its path. When it crossed the Mexican coast on Wednesday however, travelling north-east, wind speeds of 204km/h were measured.

Brian Jacobs, ZS6YZ, Deputy National Director of HAMNET, has reminded me of the Great ShakeOut, which is the world’s largest earthquake drill. It is held annually on the third Thursday of October, and millions of people participate all over the world. In 2022 over 45.6 million people registered their participation. The goal of the ShakeOut is to teach people how to protect themselves during an earthquake.

Great ShakeOut Earthquake Drills across the U.S. are coordinated by the Southern California Earthquake Center in partnership with ECA, CUSEC, state and national emergency management partners, with support from FEMA, NEHRP, NSF, and USGS.

The ShakeOut drill is simple. At the designated time (or whenever works for you or your organization), participants practice self-protective actions such as “Drop, Cover, and Hold On” or “Lock, Cover, and Hold On” if they use a wheelchair. You may want to register your group for the Great ShakeOut. Registrants will receive a certificate of participation from the ShakeOut organization.

The US Geological Survey (USGS) and Winlink are collaborating to provide “Did you feel it?” (DYFI) earthquake intensity reports via Winlink. SHARES and Amateur Radio Operators are therefore invited to send an EXERCISE Winlink “Did you feel it?” (DYFI) message to the USGS during Shakeout! In real events Winlink DYFI ground truths contribute to USGS earthquake intensity assessments and event response products, like PAGER. The PAGER system provides fatality and economic loss impact estimates following significant earthquakes worldwide and is used by governments, agencies, NGOs, private companies and citizens.

The third Thursday of October is this coming 19th, so please consider practising the sending of a notification, even if only in practice, to your local radio agency using Winlink if you can, announcing whether you imagine you “felt it”!

 Consider conducting local radio nets or functional radio exercises to test your group’s preparedness.

The ShakeOut is also an opportunity to learn more about earthquake preparedness. Participants can learn about the different types of earthquakes, how to create an earthquake safety plan, and how to make their homes and businesses more earthquake-resistant.

The Great ShakeOut is a great way to get ready for an earthquake. Many preparedness lessons from the Great ShakeOut also apply to floods, fires, landslides and other disasters. It is also a chance to connect with your community and learn how to help others in the event of an earthquake or other disaster.

Thanks, Brian, for the reminder.

This weekend has seen an annular solar eclipse, visible in large parts of North and South America. In that the distance from the moon to the earth varies, it sometimes happens that the moon is not “big” enough to block out the sun completely, and so a ring eclipse happens, also known as an annular eclipse.

Writing in sciencefriday.com, Emma Lee Gommetz notes that, while people across the eclipsed countries donned eclipse glasses and turned their gaze skyward for Saturday’s eclipse, amateur radio operators would have been heading to their transmitters. 

Eclipses have a documented effect on a layer of free-floating ions around the Earth, called the ionosphere. During the day, the sun’s ultraviolet rays and X-rays knock electrons off of their positive counterparts, separating the atmosphere into layers of charged particles. At night, the particles find their way back to one another and neutralize. When the ionosphere has a high density of electrons as a result of sunlight, radio signals (especially those at lower frequencies than those your typical radio station uses) can bounce off it and travel a great distance. But during an eclipse, darkness is focused onto specific places on Earth—neutralizing just a section of the atmosphere for a period of time. This means that eclipses, like weather and solar flares, can affect how radio works. But just how they affect it is unclear.

“We understand, on average, what the atmosphere is supposed to look like day compared to night, or June compared to January,” says Dr. Nathaniel Frissell, WA2NAF, a QSO party host and assistant professor at the University of Scranton. “But a lot of the small scale features, or the short time duration features, we just don’t have a good handle on,” he says. That’s where ham radio comes in.

During QSO parties, radio operators communicate with as many other stations as possible to see who can establish the highest number of connections, called “spots,” within a given time period. Thousands of radio connections can occur all over the country in one day. This high volume, and the fact that ham radio operators use a variety of frequencies, helps researchers pinpoint the locations where an eclipse is affecting radio contact. 

During the 2017 total eclipse, ham radio data showed that spots at a certain frequency (14 megahertz) started dropping out right as the path of totality passed over their midpoints. That data came from a NASA-funded QSO party that Frissell organized, and research based on the event showed that radio connections changed as a result of the eclipse.

Understanding how changes in the ionosphere impact different radio frequencies could help radio users better perform essential communications at distances across the world. “Ham radio operators, emergency responders…ships at sea, aircraft that are going over polar regions, they’re going to have radios that are equipped with these lower frequencies,” Frissell says. 

The fact that the eclipse was not visible from South Africa did not detract from the value of data collected by ZS stations, because our contacts with other stations in other countries could have failed to refract from the ionosphere at a point where the sky was dark. So any or all data is valuable to such research.

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.