<p>Typically seismic data should oscillate around 0 amplitude in the time domain, i.e. there should be just as much positive amplitude as there is negative (otherwise the ground would have had a net displacement in some direction). This is the energy at 0 Hz in the amp spectrum. It is like a bulk shift (DC shift) on the data.</p>

<p>So... unless the ground was permanently displaced by your seismic source, this is probably just an artifact. It could be as simple as: you used too few data to calculate your amplitude spectrum (e.g. small window, etc). Or it could be a super low frequency artifact coming from data processing.</p>

CC BY-SA 3.0
2017-11-16T23:03:37.160Z
2017-11-16T23:03:37.160Z
Antonio
<p>The two images below correspond to two processed seismic cross-sections.
My question is this: why at/near 0 Hz is there "lots" of seismic energy still present? Most if not all of the lower end of the bandwidth stops at 10 - 15 Hz.</p>

<p><a href="https://i.sstatic.net/e5R5j.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/e5R5j.png" alt="enter image description here"></a></p>

CC BY-SA 3.0
2018-04-05T20:59:51.683Z
Is this land or marine data?
stevej
CC BY-SA 3.0
2018-04-06T16:23:36.033Z
It is near-surface (9 - 50 m) land data.
nate
<seismic>
Seismic data spectral analysis
nate
# Seismic data spectral analysis

(Asked by: username_0 on 2017-11-15)

The two images below correspond to two processed seismic cross-sections.
My question is this: why at/near 0 Hz is there "lots" of seismic energy still present? Most if not all of the lower end of the bandwidth stops at 10 - 15 Hz.

[![enter image description here](https://i.sstatic.net/e5R5j.png)](https://i.sstatic.net/e5R5j.png)

**Tags:** seismic

> **Comments:**
> **username_1**: Is this land or marine data?  
> **username_0**: It is near-surface (9 - 50 m) land data.  

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## 1 answers

### Answer by username_2 on 2017-11-16. Score: 5 | Accepted answer

Typically seismic data should oscillate around 0 amplitude in the time domain, i.e. there should be just as much positive amplitude as there is negative (otherwise the ground would have had a net displacement in some direction). This is the energy at 0 Hz in the amp spectrum. It is like a bulk shift (DC shift) on the data.

So... unless the ground was permanently displaced by your seismic source, this is probably just an artifact. It could be as simple as: you used too few data to calculate your amplitude spectrum (e.g. small window, etc). Or it could be a super low frequency artifact coming from data processing.


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