| 摘要 |
<p>PURPOSE:To forecast an eruption with high reliability by measuring the underground magma which is the direct cause of the vocano eruption directly and continuously, and observing the position, size, and motion of the magma by utilizing the long wave. CONSTITUTION:Antennas 2-1 and 2-4 are installed nearby the magma 1 and signals f1-f4 received from those antennas 2-1-2-4 are amplified by receivers 3-1-3-4. Those signals f1-f4 are recorded on recorders 4-1-4-4. A correlator 5 picks up three different couples of signals from the recorders 4-1-4-4 and collates those signal couples to find reception time differences t12, t23, and t34 among those signals. A magma image constitution part 6 finds the position, size, and shape of the magma 1 according to the time differences t12, t23, and t34. Those three-dimensional magma images are recorded as time-series data at a magma data recording part 7 and an eruption forecasting part 9 makes an abnormality decision, so that an output part 10 outputs time variation information on the magma 1, an eruption forecast, etc.</p> |
