摘要 |
In one aspect, the present invention is directed to an earthquake detection and alarming apparatus, comprising: a transparent object (46) having a concave surface on the top thereof; a rollable object (34) placed on the concave surface; an apiary of light projectors (30) placed above the concave surface; an apiary of light receivers (38) correspondingly to the apiary of light projectors, the apiary of light receivers being placed below the concave surface; and circuitry for determining: (a) vibrating frequency and amplitude of the rollable object with reference to the concave surface from sensing of the receivers (38); and (b) deducing therefrom the arrival of primary waves. |