HAMNET Report 17th November 2019

The weather in the KwaZulu Natal Midlands has been a strong topic of conversation this week after a tornado ripped through the New Hanover areas of Thokozani and Mpolweni on Tuesday. Cooperative Governance and Traditional Affairs (Cogta) spokesperson, Lennox Mabaso, said several homes and public infrastructure were damaged, and scores of people were hurt.

Cogta MEC Sipho Hlomuka, said preliminary reports received by the department indicate that a number of people who sustained injuries in the incident are receiving medical attention from surrounding hospitals.

“A number of homes have collapsed, countless trees have been uprooted and the electricity supply in the area has been interrupted. Our teams are working hard to provide support to the affected communities,” said Hlomuka.

He said there are fears of missing people and possible deaths, and urged residents to be vigilant as the risk of heavy rains and severe thunderstorms continue to pose a serious danger to the province.

And on Wednesday, another tornado tried to touch down in the midlands, while heavy rains saturated large parts of central and coastal KZN. Low-lying areas quickly filled up, and gardens and roads were underwater by Wednesday evening.

Further forecasts of very heavy rain for Thursday and Friday fortunately didn’t materialize, as clouds and humidity were driven off the coast by late Thursday, resulting in a cloudless Friday.

The synoptic charts are starting to show the usual Spring and Summer low pressure trough, laying diagonally across the country, from Northern Namibia and Botswana, down to Eastern and Southern KZN, with high pressure cells off the Western and Eastern coasts of our country keeping all cold fronts firmly South of the country.

It would appear that the rainy season in the South West of the country is over, while the unpredictable summer storms start to make their presence felt in North Eastern areas. We trust that there will be enough rainfall to provide the farmers with good harvests.

Alex Schwarz, VE7DXW, has theorized for some time now that his RF-Seismograph, initially aimed at indicating band openings, seemed also to act as a real seismograph of sorts, with effects of earthquakes affecting HF noise levels and actually briefly enhancing HF propagation. Schwarz has some support from Professor Kosuke Heki of Hokkaido University in Japan, who has been researching whether changes occur in the ionosphere as a result of an earthquake.

The work of both citizen scientist Schwarz and space geodesy expert Heki caught the attention of Hackaday, the online publication with a stated goal of promoting “the free and open exchange of ideas and information.” A November 12 Hackaday article, “HF Propagation and Earthquakes”, outlines the observations of both men. According to the article, Heki “knew that changes in the ionosphere can affect GPS and GNSS receivers on the ground, and with Japan’s vast network of receivers to keep track of the smallest of movements of the Earth’s crust, he was able to spot an anomalous build-up of electrons directly above the devastating 2011 Tohoku-Oki earthquake, that preceded the earthquake by 40 minutes.”

Heki’s theory is along these lines: Chemical bonds in the rock — specifically peroxy bonds between two oxygen atoms — are broken by microfractures, leaving one side of the peroxy bond with excess electrons and the other with a positive hole. “These holes tend to migrate from high stress to unstressed areas of the rock, which leads them to eventually reach the surface, leaving it with a net positive charge,” the Hackaday piece says. “As stress in the rock below increases, the number of positive holes reaching the surface rapidly multiplies, drawing electrons from the atmosphere to balance the charge. The moving charges generate an enormous electromagnetic field that can reach all the way up to the ionosphere, creating just the kind of anomalies that Professor Heki observed.”

This week, Schwarz reported that the US Geological Survey recorded nine “significant earthquakes” on November 11, eight of which also were recorded by his RF-Seismograph. According to Schwarz, several small quakes early in the morning “opened the 40-meter band slightly, but the precursor of the quake [in Neiafu, Tonga] created a disturbance starting 4 hours prior to the quake and a total radio blackout between 03h30 UTC and 05h50 UTC. The quakes in late morning did not have a great effect on the local propagation. The one from Vanuatu created 80-meter propagation for 10 minutes only. At 23h40 UTC, another quake from Indonesia opened the 30-meter band again,” Schwarz said.

The Hackaday article concludes, “Clearly, the RF-Seismograph is not yet ready to claim to have a solid predictive ability for earthquakes. For that matter, Dr. Heki’s space-based observations aren’t ready to stake that claim either. But it certainly looks like ionospheric changes can be correlated to earthquakes, both in time and space…”

And lest you think the earth’s mantle is a settled place, may I report that 46 earthquakes around the globe, with a magnitude of more than 4.5 on the Richter scale, were reported in Friday’s global disaster news! Our planet is indeed restless.

The ARRL Letter notes that December 11 marks the 98th anniversary of the success of ARRL’s Transatlantic Tests in 1921, organized to see if low-power amateur radio stations could be heard across the Atlantic using shortwave frequencies (i.e., above 200 meters). On that day, a message transmitted by a group of Radio Club of America members at 1BCG in Greenwich, Connecticut, was copied by Paul Godley, 2ZE, in Scotland.

While the first two-way contact would not take place until 1923, the 1921 transatlantic success marked the beginning of what would become routine communication between US radio amateurs and those in other parts of the world — the birth of DX.

To commemorate this amateur radio milestone, Maxim Memorial Station W1AW will be on the air through the day on December 11 with volunteer operators. The goal is to encourage contacts between radio amateurs in the US and Europe while showcasing the significance of the transmissions that pioneered global communication and laid the groundwork for technology widely used today.

The event will run from 13h00 until 00h00 UTC. Some details are still being worked out, but operation will focus on 40 and 20 meters SSB.

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