| 摘要 |
PURPOSE:To discriminate a volcanic earthquake exactly at the failure time at any observing station, by deciding in accordance with either only at A group seismic stations installed in the mountain or both at these seismic stations and B group seismic stations installed around an earthquake is detected in a prescribed timer period. CONSTITUTION:A timer 3 is operated through a reception treating part 1 and a microprocessor 2 in accordance with the rising of detecting an earthquake at first either by A group seismic stations A1, A2- installed in the volcanic mountains or by B group seismic stations B1, B2- installed around volcanos. When an output of a seismic detection from the seismic stations A1, A2- within a timer period of this timer 3 is received, it is decided as a volcanic earthquake having the low propagation speed by a processor 2 and the result is stored in a memory 4. While, when the output of the seismic detection from the stations A1, A2- and that from the stations B1, B2- are received simultaneously, it is decided as an earthquake at a distance place having the high propagation speed. By the decision on basis of the output of detecting reception within the prescribed time, the volcanic earthquake is discriminated exactly even at the failure time of any observing station. |
