Some observations and characteristics of type Pc 1 geomagnetic micropulsations

General characteristics of earth currents and geomagnetic micropulsations in the Pc 1 band (0.2- to 5-sec period) based on observations made by the Electrical Engineering Research Laboratory, the University of Texas, at three sites are reported. Examples of recent active periods in September–October 1963 indicate relations between orthogonal E and H components. Simultaneous records between Austin, Texas, and LaGrande, Oregon, indicate a time delay in the signal envelopes of 2 to 3 sec, the Oregon signals leading.