Today, 31 years ago, on November 11, 1994 (October 9, 1994 in the Lunar Calendar), China developed the world's widest frequency seismometer. On November 11, 1994, the world's widest frequency seismometer was successfully developed at our National Seismological Institute, and the national "eight-fifth" key research achievements passed technical identification by the National Seismological Bureau. Experts believe that this achievement reached the leading international level. This seismometer, called JCZ-1, is extremely sensitive, and the range of observations covers the broad frequency range from high frequency earthquake waves to solid tide.