Abstract
Portable proton magnetometers with a sensitivity of 0.1nT operated before, during and after the moment of the magnitude M=7.3, 17th May 1976, Gazly earthquake. Magnetometers were operating essentially at the epicenter at the Kara-Kyr station and 170km to the northeast at the Tamdybulak. Measurements were made during the period 13-22 May 1976. No variations of the geomagnetic field total force with an amplitude exceeding 0.1nT were seen during the earthquake. Similar results were obtained from the magnetic measurements during 12 aftershocks with M≥4.5 which followed the main quake. The profiles of the changes of the geomagnetic field during these 12 aftershocks were stacked. The stacked plot shows no variations with amplitude greater than 0.1nT.
