Accession Number : AD0712632


Title :   ROTATIONAL SEISMOMETER


Descriptive Note : Final rept. 15 Jun 1968-15 Jun 1969


Corporate Author : CALIFORNIA UNIV BERKELEY DEPT OF MATERIALS SCIENCE AND ENGINEERING


Personal Author(s) : Rodgers, Peter W ; Dann, Charles A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/712632.pdf


Report Date : 15 Mar 1970


Pagination or Media Count : 31


Abstract : Elastic wave theory predicts that the elastic waves generated by an earthquake and other seismic events include a measurable component of horizontal elastic rotation. Several rotational seismometers have been designed to measure this rotational component. The first design consisted of a large inertial ring of mercury terminated in a coaxial set of stand pipes housing capacitive transducers to sense the displacement of the mercury in the stand pipes. The second design consisted of a continuous inertial ring of water with a thermistor transducer to detect flow within the pipe. The third design consisted of a continuous inertial ring of water with a thin paddle placed in the path of flow. Problems encountered involved spurious signals due to a 'flexible' pipe, electronic noise and drift, temperature stabilization, and moisture penetration into the transducers. The capacitive transducer seemed to be the most promising, and experimentation is continuing using this transducer within a rigid steel pipe.


Descriptors :   *SEISMOMETERS , EARTHQUAKES , MERCURY , MOISTURE , NOISE(RADIO) , OPERATION , ROTATION , SENSITIVITY , STABILIZATION , TEMPERATURE , THERMISTORS , TRANSDUCERS , WATER


Subject Categories : Seismology


Distribution Statement : APPROVED FOR PUBLIC RELEASE