Development and Testing of a Shielded Ocean-Bottom Seismometer to Reduce Seafloor Low-Frequency Noise

π吗?美国将申请资金开发和测试一种屏蔽式海底地震仪（SOBS），以减少电流产生的倾斜噪声对海底低频地震观测的影响。灵敏的地震传感器将被放置在一个大的圆形钢盾内，这个盾也可以用作仪器。锚。预计这种屏蔽将减少传感器附近的电流，大大降低噪声水平。大量海底地震仪（OBS）船队的建立能够记录超过一年的时间，这使得利用地震观测来研究海洋下的地球结构成为可能，其分辨率比以前高得多。然而，与陆地站点相比，这些传感器的低频性能较差，因为洋流引起的噪音水平非常高。这些高水平使得目前的OBS观测对洛夫波的观测、剪切分裂和接收函数分析几乎毫无用处，并且可以阻止在嘈杂的地点探测到来自大地震的剪切波。更广泛的影响：一位评论者说，一种更好的记录水平地震能量的方法（例如爱波）将使整个海洋（和陆地）地球物理学界受益。在这方面，目前的OBS观测在成像地球结构的能力上是半受限的，因为这种剪切波数据不容易分辨。任何增强这些记录的解决方案都是朝着更好的数据分辨率和解释迈出的一步。

The PI?s request funding to develop and test a shielded ocean bottom seismometer (SOBS) as a strategy for reducing the effect of current-generated tilt noise on low-frequency seismic observations made at the seafloor. The sensitive seismic sensor will be placed within a large circular steel shield that also serves as the instrument?s anchor. It is expected that this shield will reduce the current flow near the sensor reducing noise levels greatly. The establishment of fleets of large numbers of ocean bottom seismometers (OBS) capable of recording for more than a year has made it possible to study Earth structure beneath the oceans using seismic observations in much greater resolution than previously possible. The low frequency performance of these sensors is however poor compared to land sites because of very high noise levels caused by ocean currents. These high levels makes current OBS observations nearly useless for observations of Love waves, shear splitting, and receiver function analysis and can prevent the detection of shear wave arrivals from even large earthquakes at the noisier sites. Broader Impacts: One reviewer said that a better method for recording horizontal seismic energy (e.g. love waves) will benefit the entire marine (and land) geophysical community. In this regard current OBS observations are semi-limited in their ability to image Earth structure because this shear-wave data is not easily resolved. Any solution to enhance these recordings is a step toward better data resolution and interpretation.