On noise reduction in vertical seismic records below 2 mHz using local barometric pressure
On noise reduction in vertical seismic records below 2 mHz using local barometric pressure
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DOI：
10.1029/95gl03369
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发表时间：
1995-12-15
影响因子：
5.2
通讯作者：
Widmer, R
中科院分区：
文献类型：
--
作者：
Zurn, W;Widmer, R
我们提出了一种简单的方法来减少频率低于 2 mHz 的垂直地震记录中的噪声。该方法包括从重力记录中减去本地记录的、按比例缩放的大气压信号。比例因子与频率无关并且可以线性估计。从数据来看。虽然这种压力校正以前仅用于潮汐记录的分析，但它在正常模式带的低频端同样有效，我们使用 1994 年色丹和玻利维亚大地震的重力记录来证明这一点。我们的例子还表明，这种校正可以实现远低于新低噪声模型 (NLNM) 的噪声水平 [Peterson, 1993]。校正的成功还揭示了在安静的天文台中产生低频地震噪声的物理过程。
We propose a simple method for the reduction of noise in vertical seismic recordings at frequencies below 2 mHz. The method consists in subtracting: the locally recorded, scaled, atmospheric pressure signal from the gravity record. The scale factor is frequency independent and can be linearly estimated. from the data. While such a pressure correction was previously only used in the analysis of tidal records, it is equally efficient at the low-frequency end of the normal mode band and we use gravity recordings of the big 1994 Shikotan and Bolivian quakes to demonstrate this point. Our examples also show that this correction permits to achieve noise levels well below the New Low Noise Model (NLNM) [Peterson, 1993]. The success of the correction also sheds some light on the physical processes responsible for the generation of low-frequency seismic noise at quiet observatories.