Results of a Comparison of Electromagnetic Tiltmeter (TEM Type) with Quartz Pendulums (VM Type) at the European Underground Laboratory of Geodynamics of Walferdange

Abstract

The results of a comparison between electromangnetic tiltmeters (TEM) and quartz pendulums (VM) at the Laboratory of Geodynamics of Walferdange have been analysed by a global method. The mean result of all instruments fits very well with those obtained in Western Europe, but the EW component of TEM 16 gives a significantly lower value for M₂ than those given by VM pendulums. This may be due to a cavity effect. Diurnal waves for the EW component are in very good agreement between themselves as well as with the Molodensky model 2 introducing the dynamic effects of the Earth's liquid core. The results at Walferdange have a particular importance because instruments working upon basically different principles give the same resonance effects .