Report: California Earthquakes Disrupted HF Propagation on 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...
http://www.arrl.org/news/view/report-california-earthquakes-disrupted-hf-propagation-on-west-coast