Wikipedia
Spacequake
In astrophysics, a spacequake is a temblor in the Earth's magnetic field. Though occurring in space, the effects of a spacequake can reach the surface of the Earth in the form of electromagnetic reverberations. The total energy in a spacequake can rival that of a magnitude 5 or 6 earthquake.
Spacequakes are measured using a magnetometer and displayed with a magnetogram.
The precursors for a spacequake were discovered by THEMIS in 2007, and were first reported in April 2010 in a publication in the Geophysical Research Letters.