2

This YouTube video asks the question if the 2016 Kaikoura earthquake was caused by the ship the Amazon Warrior conducting "seismic blasting".

Is that even possible?

Green Party MP Steffan Browning posted on Facebook said it was off the coast of New Zealand the day before the earthquakes.

Steffan Browning MP

Post reads,

Sorry to see the world's biggest seismic blasting ship the Amazon Warrior off my beach, Rarangi in Cloudy Bay tonight. Hiding from Wellington's protestors today, this ship has been allowed in by Energy and Resources Minister Simon Bridges as part of the National Party's deep sea oil gamble. Spoiling our super moon viewing, this ecological thumper needs moving on out of New Zealand's EEZ.

  • 5
    The last link (youtube video) definitely makes this claim, but I don't see anything about it in the FB or other links (just that there is a ship there and he'd like it gone). Do you have a source where Browning makes the earthquake claim? – Is Begot Nov 18 '16 at 2:43
  • 1
    I think Steffan's claim is that it's spoiling his viewing of the supermoon... Not entirely sure how it could do that, but that's his complaint. – Paul Hutchinson Nov 18 '16 at 8:43
  • 4
    Hint: Don't google "Amazon Warrior" to learn more about the ship. better add "ship". – daraos Nov 18 '16 at 9:17
  • @IsBegot After checking out the video, I think the claim is that the Amazon Warrior is a "seismic blasting" ship. That is not what the shipyard that built it says, and the owner is a company that collects seismic data. It is not supposed to blast anything. So the first question would be: Is the Amazon Warrior a "seismic blasting" ship? The guy in the video takes this for granted. – daraos Nov 18 '16 at 9:33
  • Had to look up 'seismic blasting', en.wikipedia.org/wiki/Seismic_source. Appears it can be a towed array of equipment, so it may be possible it was conducting the exploration. – RomaH Nov 18 '16 at 14:15
3

Referring to GNS Science seismologist Dr John Ristau, the answer is no due to the following reasons.

  1. The origin of the quake (hypocenter) was about 100 kilometres south of where the ship was stationed.

The hypocenter of an earthquake is the location beneath the earth’s surface where the rupture of the fault begins. The epicenter of an earthquake is the location directly above the hypocenter on the surface of the earth. Source: Earthquake Facts

However, the above reason provided by Dr. John Ristau is not backed up by research evidence as the distance to which the increased pressures can migrate and cause earthquakes and the timing is still uncertain.

Fact 5: Induced seismicity can occur at significant distances from injection wells and at different depths. Seismicity can be induced at distances of 10 miles or more away from the injection point and at significantly greater depths than the injection point. Source: Induced Earthquakes

The seismologists also found that earthquakes in this particular study could occur as much as 5-7 miles away from the well. The distance to which the increased pressures can migrate and cause earthquakes in other areas is still uncertain. Another uncertainty is timing between when the water is injected and when the earthquakes begin. Source: Induced Earthquakes Throughout the United States

  1. Seismic blasting is used to locate and estimate the offshore oil and gas reserve size by the use of multiple airgun arrays that emit thousands of high-decibel explosive impulses to map the seafloor or through explosions. However, these impulses do not travel deep enough to cause quakes and also quakes tend to originate well beneath the earth's surface.

But Ristau says the Warrior isn't to blame for Monday morning's quake. Firstly, the quake originated about 100 kilometres south of where the ship was stationed. There is also no way the blasts were deep enough - quakes originate well beneath the earth's surface. And the energy from the explosions or airguns wouldn't have had the power to cause a shake, he says. For context - South Island quarries constantly set off explosions bigger than those the ship would have used. Source: Why quakes weren't caused by seismic blasting or 'unzipping' faultline

Seismic signals produced by the air guns consist of bubbles of compressed air and these are not still researched or noted to induce earthquakes through artificial stress. An example of the bubble pulse produced by air guns can be viewed here.

Marine acquisition of seismic data is generally accomplished using large ships with one or multiple airgun arrays for sources. Airguns are deployed behind the seismic vessel and generate a seismic signal by focusing highly pressurized air into the water. Receivers are towed behind the ship in one or several long streamer(s) that are several kilometres in length. Marine receivers are composed of piezoelectric hydrophones, which respond to changes in water pressure.

2.2 The airgun source: The latest version of the airgun is the sleeve-gun which has the ability of producing a much more spherical bubble than the earlier generations of airguns. A single airgun produces a pulse of energy (or signature). Although the initial energy burst is reasonable, a complex pressure interaction between the air bubble and the water causes the bubble to oscillate as it floats towards the surface. This effect produces the extraneous bursts of energy following the initial burst. Source: Introduction to seismic processing and imaging

  1. Seismic surveys are also blamed to cause adverse impacts on marine life. However, the actual research evidence does not agree with that conclusion.

For more than four decades, seismic surveying and countless research projects (both in Australia and world-wide) have shown no evidence to suggest that sound from oil and gas exploration activities in normal operating circumstances has harmed marine species or marine ecological communities. Nor have studies found any significant disruption of marine animal behaviors that would affect survival or reproduction. Source: Seismic surveying

Coral damage was also not observed during seismic surveys.

One of the most comprehensive research studies carried out anywhere in the world was conducted by Woodside in 2007 in and around Scott Reef off the north-west of Australia. This extensive research was done by leading researchers from all over the world who studied the impacts of a seismic survey on marine life. They concluded that the survey caused: no significant, long-term impact on fish behaviour in either caged or wild fish, no hearing impacts (temporary or permanent) found in fish, no evidence of coral damage, no physiological damage to fish as a result of the seismic survey, no long-term effects on fish or coral populations and no observed physiological effects or mortality in other marine fauna. Source: Seismic surveying

The sound intensity and pressure of seismic surveying is 255 dB re 1µPa @ 1m while in comparison, undersea earthquake's sound intensity and pressure is 272 dB re 1µPa @ 1m.

  1. Artificial stress powerful enough to cause quakes such as building dams, injecting liquid into the earth's crust, coal mining and extracting oil and natural gas from regions where there is high tectonic activity are noted to cause a massive change in stress load of the earth's crust which tend to trigger earthquakes. These earthquakes are called as induced seismicity.

Hydraulic fracturing, long-term wastewater injection, and enhanced oil recovery have all induced earthquakes in the United States and Canada in the past few years (Horton, 2012; Gan and Frohlich, 2013; Holland, 2013). As discussed above, wastewater disposal is responsible for the vast majority of the increase, including the largest and most-damaging induced earthquakes (Horton, 2012; Keranen et al., 2013; Frohlich et al., 2014; Rubinstein et al., 2014).. Source: Myths and Facts on Wastewater Injection, Hydraulic Fracturing, Enhanced Oil Recovery, and Induced Seismicity

However, not all injection wells (hydraulic fracturing, wastewater disposal, and enhanced oil recovery) induce major earthquakes.

Most injection wells do not cause felt earthquakes. More injection wells may be inducing earthquakes, but current studies are limited to the largest earthquakes and those with the best seismological and industrial data available. Further study of other earthquake sequences may reveal that additional felt earthquakes are induced. It is likely that smaller induced earthquakes are occurring and are too small to detect. In some sense, all hydraulic fracturing induces earthquakes, although typically microearthquakes. When production engineers hydraulically fracture, they are intentionally cracking the rock, causing microearthquakes that are typically smaller than M 0. Source: Myths and Facts on Wastewater Injection, Hydraulic Fracturing, Enhanced Oil Recovery, and Induced Seismicity

Fortunately the energy produced from seismic blasting is not powerful enough to cause quakes since the range of impulses fall between 1000 psi (Accelerated Weight Drop Thumpers) to 3000 psi (air gun).

TL;DR: There is no scientific evidence to support the claims that offshore seismic surveying causes earthquakes or triggers a fault.

These claims have been called "ridiculous" by the oil industry, with GNS saying seismic testing has no effect on earthquakes. "Claims that offshore seismic surveying was responsible for Monday morning's earthquake are ridiculous and nothing short of scaremongering. There was no offshore seismic survey occurring in the area at the time," says Petroleum Exploration and Production Association of New Zealand chief executive Cameron Madgwick. "In addition, there is absolutely no scientific basis to support claims that offshore seismic surveying in any way causes earthquakes or triggers a fault." Source: Quake myths busted: Seismic surveys, mega quakes and supermoons

  • Is 100 km evidence for or against? It doesn't sound that far away to me, but I don't have much feel for it. Have you a reference that will help put that figure into context? – Oddthinking Nov 19 '16 at 12:50
  • From the Wikipedia these are a litre of air at 2000 psi. Several times the bang of a tire blowout. – Keith McClary Nov 19 '16 at 22:33
  • @Oddthinking- The 100 km evidence is against the claim because this shows that the ship was 100 km away from the hypocenter of the earthquake. – pericles316 Nov 24 '16 at 5:25
  • @pericles316: Yes, I understood that. What I don't have a feel for is whether that is a long way in geological terms. I think you would agree that 100m away would be considered very close - evidence suggestive of a causal relationship. What about 1km? Would that be considered close? Is 100 km close? I don't know. Is that within the "range" (whatever that means) of the shock waves travelling through water and rock? [I am not arguing either way here, I am merely saying that other readers, like me, may lack a meaningful sense of scale here.] – Oddthinking Nov 24 '16 at 5:45
  • @Oddthinking-I am searching for that evidence you are mentioning but the main takeaway is 1000 psi to 3000 psi impulses produced by the seismic sources are not known to cause earthquakes even if the source is 100 km away or 100 m near the hypocenter of an earthquake. Also check out this link for man made quakes-wired.com/2008/06/top-5-ways-that. However i cannot produce this as evidence for your query. – pericles316 Nov 24 '16 at 7:06

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .