The unexpected usefulness in research of the Press-Ewing seismograph system (Press, Ewing and Lehner, 1958) has stimulated further efforts to obtain even higher seismograph sensitivity in the period range beyond 100 see. A major difficulty has been in maintaining pendulum stability at long periods. This paper describes a stable long-period seismometer and gives results from several seismograph systems incorporating long-period pendulums and galvanometers.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.