What is the postulated mechanism for solar cycles influencing volcanic activity? Hard for me to see how magnetospheric effects with relatively modest field strengths can reach down through the crust to noticeably stir things up.
I’m no scientist but people who are say there’s a connection between solar activity & the lack of sunspots and earthquakes & volcanoes, etc. Some links (there are many articles):
https://www.heartmath.org/gci-commentaries/the-connection-between-solar-activity-volcanic-eruptions-and-earthquakes-weather-and-cycles-on-earth/
http://www.almanac.com/content/space-weather-sunspot-numbers-and-solar-activity
https://churchofthecosmos.wordpress.com/2010/05/21/the-connection-between-solar-activity-volcanic-eruptions-and-earthquakes-weather-and-cycles-on-earth/
https://astronomynow.com/2015/07/17/diminishing-solar-activity-may-bring-new-ice-age-by-2030/
http://www.washingtonsblog.com/2011/08/can-solar-activity-cause-earthquakes-volcanoes-and-extreme-weather.html