My bet is that it was due to natural causes. Underwater currents, seafloor landslide or something similar.
That humans did this undetected is possible but why would anyone with the capability bother? It would likely cost more to pull off than it could possibly be worth. And, for a state actor, the consequences of getting caught far outweigh any benefit.
Doesn't seem like this thing would've collected much interesting data about a nuclear explosion.
Speed of temperature, speed of water would be possible results of a nuclear detonation, no?
And methane could be a side effect of dislodging some barrier to a deposit?
I’m admittedly out of my element, but it seems like those are metrics that could be affected by an accident (or test) of that nature.
It's roughly a thousand mile trip by water from Kiel, Germany to Nenoksa, Russia... and the incident in Russia wasn't a nuclear explosion of the sort you'd see in a bomb, it was an explosion that involved radioactive material.
If I'm understanding correctly, they have the exact hour of signal loses. Ships have predictable and registered routes, (except military). First thing to do should be to take a look to the ships in the area around this timestamp.
If trying to save people and all nations with science was not enough difficult, now with a 30% more of sabotage. Fantastic.
It is only really traceable through radiation, because our instruments are very accurate and the signal is very clean - it does not change much through natural causes.
Russia was my first thought, but you can't hide a submarine depth of 22 meters.
Conversely, get a small boat, commodity diving gear and 3 dudes, and this is easy to do. You get this kit for a few grand.
The depth is an issue because a submarine can't go deep enough to be undetected there. It'd be visible to aircraft and boats in water that shallow.
In this paragraph I was including the possibility of somebody blowing deliberately the station with dynamite for example.
Those things are expensive so the question to ask here is if the station is still lying in the seafloor or was removed by somebody. If is possible to recover it, even partially, could make a big difference for the research team.
I remember putting into the ocean a cylinder full of sensors. It was relatively small, an R2-D2 sized thing or so. The main researcher of the oceanographic campaign was literally sweating with the idea of some chain breaking in the process and losing the small cube property of the university. Each time it was used was like dumping the economic equivalent to a luxury car in the open sea hanging on a chain and hoping that all went ok, several times in a day.
A real nuclear explosion - even a small one - is hard to mistake or conceal. Enormously bright double flash, big shock wave, hundreds of tons of irradiated dirt lofted into the stratosphere, etc.
More likely, it was an inadvertent "dirty bomb" event. Assuming this was associated with the purported nuclear-powered cruise missile "Skyfall" (NATO designation), it sounds like their reactor had a prompt criticality incident. This will make a reactor explode, but it's a small energy release compared to an engineered nuclear explosion.
The US had a prompt criticality reactor accident in 1961 [1]. A nominal 3 MW thermal power reactor reached 20GW in 4 milliseconds when things went wrong. Not a nuclear explosion at all, but it killed three people.
I wish we'd just give the Russians all our data from project Pluto [2], so they'd give up this nuclear powered cruise missile development path.
> Other factors, such as a massive storm, heavy currents, or even marine animals, were ruled out as potential causes owing to the weight of the instrument.
This part is nonsense. Both massive storm, heavy currents and 40000 Kg sperm whales are able to displace easily matherial of only 250 Kg or shred submarine cables.
I would not discard pirate fishing trawl entering deliberately in a restricted/protected area (supposedly with plenty of fishes). Is pretty common.