(Source: Southgate ARC)

The ARRL reports earthquakes in California disrupted HF propagation on the west coast

British Columbia radio amateur Alex Schwarz, VE7DXW, said that an Independence Day magnitude 6.4 earthquake in California’s Mojave Desert and multiple aftershocks negatively affected HF propagation on the US west coast.

Schwarz, who maintains the “RF Seismograph” and has drawn a correlation between earthquake activity and HF band conditions, said the radio disruption began at around 1600 UTC on July 4, and continued into July 5. He said that on July 4, the blackout was total except for 20 meters, where conditions were “severely attenuated,” Schwarz said. The RF Seismograph also detected the magnitude 7.1 earthquake on July 6 in the same vicinity, Schwarz reported. The distance between the monitoring station in Vancouver, British Columbia, and that quake’s epicenter is 1,240 miles.

“Things are back to normal after the strong quake, as far as the ionosphere is concerned, but the unrest has not stopped yet,” Schwarz told ARRL on July 8.

Read the full ARRL report at
http://www.arrl.org/news/view/report-california-earthquakes-disrupted-hf-propagation-on-west-coast