Comparison of Seismic Sounds with Typical Examples of Sounds in Water and Air

The tabulation below has been prepared to address the often confusing claims made by environmental groups such as Oceana  and Wild Migration regarding the loudness and hence perceived impacts, of seismic pulses in water. The tabulation compares the loudness of seismic pulses with other sounds in water and also relates these to typical sounds we are all aware of in air.

Examples of sound levels in dB_updated 141010

Key points that can be drawn from this tabulation include:

1. Seismic pulses are very obviously at a similar loudness to a jet taking off – NOT 100,000 times louder as implied by Oceana in their absurd infographic;

2. Ironically, if Oceana were correct in their claim, seismic pulses would have to be louder than the Krakatoa eruption which cracked walls and broke windows up to 160km away, created a 37m tidal wave and was heard up to 4700km away!  Common sense tells us that seismic pulses are nowhere near the loudness of atomic explosions and pale into insignificance compared to the Krakatoa eruption;

3. Furthermore, in their infographic, Oceana imply that the sound of a motor cycle is 10,000 time louder than normal conversation. How can they believe the public is so gullible as to believe that!? It is ridiculous, given it is only 16 times. Also, they imply that a jet taking off at 140dB (which is incorrect as it would have to be at 50m, not 1m) is 10,000 times louder than a motor cycle. Again, that is totally false;

4. There are many natural sounds in the ocean that are similar to or greater than seismic sounds (calving/colliding icebergs, sperm whale clicks, earthquakes, lighting strikes, undersea eruptions).

5. There are many sounds made by marine life that are at similar levels to the levels that they would experience just a few hundred metres from an active seismic vessel.

Unfortunately, many people including senators, other environmental groups and the media have obviously believed the implication by Oceana that seismic pulses are 100,000 louder than a jet taking off.

In conclusion, when we look at the facts and science, we are left to ponder why environmental groups like Oceana and Wild Migration get their facts so wrong and appear to intentionally spread fear and confusion in the community.

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Comments

  1. Great tabulation – it explains a lot! I also agree that Oceana’s “infographic” is absurd and total fiction.
    Even if “intensity” is representative of a sound’s loudness, which I understand it is not, Oceana has made a further major error (or is it a deliberate oversight) in their calculations. Even my high school maths tells me that if a motor cycle at 100dB is 10,000 times more “intense” than normal conversation at 60dB (ie 4 factors of 10) and a jet taking off (at 50m) at 140 dB is 10,000 times more than a motor cycle (another 4 factors of ten) then a seismic pulse at 250dB should not be 100,000 times more “intense” (5 factors of 10) than the jet at 140dB, but 100 billion times more “intense” (11 factors of 10)!!!???
    It would appear that Oceana probably decided that number was too unbelievable (and incredibly outrageous) for the public so scaled it back to something people might believe if they really want to.

  2. Captain Obvious says:

    Umm guys, the greenies are right. Wikipedia has a nice little explanation of it: http://en.wikipedia.org/wiki/Decibel

  3. johnnwdhughes says:

    That’s not a good source for your information. The issue here is that 10dB in amplitude or pressure (loudness) is a factor of 2 but 10dB in power (intensity) is a factor of 10. Marine animals are susceptible to loudness (amplitude or pressure). The greenies are incorrect when they claim seismic pulses are 100,000 times louder than jets taking off when, in fact, they are the same (a jet taking off – 180dB in air is equivalent to 242dB in water – a typical seismic pulse).

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  1. […] Comparison of Seismic Sounds with Typical Examples of Sounds in Water and Air […]

  2. […] Comparison of Seismic Sounds with Typical Examples of Sounds in Water and Air […]

  3. […] Comparison of Seismic Sounds with Typical Examples of Sounds in Water and Air […]

  4. […] be seen in an article already published on this website, drawn from readily available information, comparing seismic sounds with typical sounds in water (and air), a typical seismic source is approximately 230dB whereas an atomic explosion is 248dB in air BUT […]

  5. […] not a figment of anyone’s imagination) and the science tells us why.  Much of this science, such as other sounds in the ocean, the sounds of breaching whales, Antarctic ice sounds, the reaction of cetaceans to seismic sounds, […]

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