A Prototype Ocean Seismic Network (OSN) Deep-Sea Borehole Seismograph

研究目的是修改和测试现有的宽带地震仪，以便最终安装在ODP于1991年3月钻探的海洋井眼OSN-1上（第136条）。通过增加海底地震观测站来扩大全球地震仪的覆盖范围，将改善地震定位，并使对地球深部速度结构的测定更加准确。了解地震发生的原因和地点对减轻这些自然灾害至关重要。地震引起的地球运动也提供了关于地球深部结构的详细信息。这些信息对于理解地球磁场和地球表面矿产资源的分布等现象至关重要。然而，我们测量地震的能力受到地震仪放置的地理限制的严重限制。到目前为止，地球表面三分之二被水覆盖的地方还无法被地震仪探测到。在海洋-海底观测站安装钻孔地震仪是一种解决方案。这项研究是建立海洋观测站网络的第一步：对能够在宽频带上记录地球运动的钻孔地震仪进行改造和陆地测试。

The research objective is modification and testing of an existing broadband seismometer for eventual installation in ocean borehole OSN-1, drilled by the ODP in March of 1991 (Leg 136). Augmentation of world-wide seismograph coverage through the addition of ocean floor seismic observatories will improve earthquake location, and allow the more accurate determination of deep Earth velocity structure. %%% Understanding why and where earthquakes occur is essential to mitigating these natural hazards. The earth motions induced by earthquakes also provide detailed information on deep earth structure. Such information is crucial to understanding such phenomena as the Earth's magnetic field, and the distribution of mineral resources on the Earth's surface. Our ability to measure earthquakes, however, is severely limited by geographic constraints on the placement of seismometers. Heretofore, the two-thirds of the Earth's surface that is water-covered has been inaccessible to seismometer coverage. Emplacement of borehole seismometers in ocean-sub-seafloor observatories is one solution proposed. This research is the first step in the creation of a network of ocean observatories: the modification and land-testing of a bore-hole seismometer capable of recording earth motions over a wide band of frequencies.