A QUAKE IN EARTH'S MAGNETIC FIELD: When a CME from the sun struck Earth on April 22nd, our planet's magnetic field reverberated from the impact. A day later, a stream of solar wind arrived, hit, and had the same effect.

In Lancashire, England, a magnetometer operated by Stuart Green captured the quaking of Earth's magnetic field: [link to spaceweathergallery.com]

"The data clearly show when the relative calm was shattered on April 21st at around 16:30 (UT) when the CME struck, being quickly followed by fast flowing solar wind from a large and persistent coronal hole," says Green. "The rumblings have been continuing through the intervening days."

[link to spaceweather.com]