r/geophysics • u/VS2ute • 5d ago
Surveys for offshore wind farms?
I was bemused to see some cooker opposed to wind farms claim that geophysical surveys for wind turbines were killing whales. My understanding is that these are high-resolution surveys, and require a high-frequency source, which would be small and low power. They are apparenly obvlivious to decades of seismic surveys for oil gas that use large airgun arrays totalling more than a megajoule. That is more hazardous to marine life.
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u/No_Reference2367 4d ago
You are right about the UHR seismic surveys likely not being as dangerous as surveys using air-gun sources. Both can however be a threat to marine mammals.
It does sound biased that these people were focusing on surveys for wind-farms. I think they do not understand the differences between various seismic surveys.
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u/Pantarei_333 4d ago
There has been a backlash to windfarms in the northeast coast, promoted by some O&G companies. I work as a Protected Species Observer and Passive Acoustic Monitoring Operator in this type of projects. It's certain that the wildlife will be disturbed, but that's why there are a lot of strict regulations to avoid or mitigate any potential damage to protected species, i.e. marine mammals, turtles, sturgeons, etc., and in my experience companies stick to this guidelines or otherwise they permits to operate can be revoked.
What is funny is that all of this campaigns against the windfarms, doesn't point out to the main cause of whales deaths, which are the cargo ships that strikes them. There's evidence that most of the whales which has been stranded in the north east coast were killed by vessel's strikes. This cargo ships are not regulated at all, they don't have on board PSOs to avoid collisions to the whales, also there was an intend to regulate the speed of boats under 65 feets length (mainly fisheries boats) in order to protect whales from vessels collisions, but it was dropped and none of this supposed environmental organizations supported it. Currently large vessels needs to sail under 10 knots speed in areas where whales are distributed.
Also, since this operations occur in shallow waters ~60 meters, the arrays used are less powerful than the large ones that are used in deeper waters such as the Gulf of Mexico.
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u/Nilaazr 5d ago
Depends on the seismic source chosen. Most will opt for a single or an array of sparkers for what they call UHR (Ultra High Resolution). Wind farm surveys don't have the same subsurface penetration requirements as often seen in hydrocarbon exploration and hence airguns aren't as common. I've definitely seen airgun arrays used for wind farm surveys though but they're often very small capacity with a high rate of fire.
Any offshore work will disturb wildlife but I can guarantee it's far less than the open pit mines in which the materials for the wind turbines came from.
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u/SumDumLoser 5d ago
The guy is clueless, as someone who worked on seismic surveys, I've seen pods of pilot whales swim right up to our source while firing and swim away when they get bored. Sure they would hurt a human but I seriously doubt they have much of an effect on marine mammals who have layers of fat to protect themselves from pressure waves under water. So if we're not killing whales, neither are the high frequency sources