The discovery
On September 26, Swiss-based Nord Stream AG, the operator of the Nord Stream pipelines, informed Danish authorities of a pressure drop at Nordstream 2 landfalls in Russia and Germany. As early as 13:56 Danish local time, the national shipping authority (Søfartsstyrelsen) issued a navigational warning for a sea area southeast of Bornholm after a leak in the Exclusive Economic Zone was discovered.
At that time, a natural cause still seemed possible. However, this assessment changed by the same evening at the latest, when Nord Stream AG again contacted the coastal services to report a pressure drop in Nord Stream 1. It was followed at 20:41 by another warning for shipping, this time from Sweden. About 80 kilometers northeast of the first leak, two more plumes were spotted on the sea surface in the EEZs of Denmark and Sweden. But it would not stop there. Two days later, on Wednesday, September 28, the Swedish Sjöfartsverket finally learned of a fourth leak , only 4.8 kilometers (about 2.6 nm) from the leak site found on the evening of September 26.
The unthinkable had occurred. The two pipelines, each with two pipes made of high-quality steel coated on the inside and outside and a stabilizing concrete coat, whose massive construction was to supply Germany and parts of the EU with cheap Russian natural gas over a distance of 1,224 kilometers, had become the target of an attack.
Initial indications of sabotage were provided by seismic events in the southwestern Baltic Sea region recorded seventeen hours apart on September 26. The earlier, weaker earthquake at 2:03 Central European Summer Time (CEST) had a Richter magnitude of 1.9, while the later and stronger seismic event at 19:03 CEST had a magnitude of 2.3. The Nord Stream events were perceived differently in the countries bordering the southern Baltic Sea. Björn Lund, ao. prof. of seismology at the Swedish National Seismological Network (SNSN), stated in his response to my written question that the blasts were well recorded by about 60 SNSN seismographs at a distance of up to 1200 km. In Denmark, due to geology and local noise conditions , only two Danish stations (GEUS) on the island of Bornholm provided data. The signal-to-noise ratio (SNR) problem also affected Germany, where only the first blast was recorded. More data is available from NORSAR, which disseminates unfiltered registrations.
Björn Lund identified them as man-made seismic events at a very early stage. This was supported by the fact that the tremors were recorded in a marine area with low seismic activity, that the wave characteristics of earthquakes look different, and that magnitudes of this size would be harmless as tectonic tremors. In addition, the Swedish university professor was also the first to bring up the possibility of another detonation in the narrow time frame to the second blast. Björn Lund further confirmed his earlier conjecture, however, that around 19:04 CEST a second and a third blast followed with 8 seconds delay. The results of the joint investigation of his SNSN with Denmark’s GEUS and the Norwegian institute NORSAR are expected to be published in 2023, and are highly relevant because, so far, there has only been talk of two explosions and four leaks.
The location
Although the location of the gas leaks seems random at first, a meaning can be derived from the three leaks, which are relatively close together. They are concentrated within a small radius at a location that has a distinctive feature: they form the termination of the parallel pipeline in deep waters. After that, Nord Stream 1 cuts through Danish territorial waters just ten kilometers from the Bornholm coast, while Nord Stream 2 turns south, bypasses the center of a Chemical Munitions Dumpling Grd. and Danish territorial waters. The pipelines then only run parallel to the German coast again southwest of Bornholm at the level of the Adlergrund. There, the Baltic Sea initially reaches a depth of 47 meters before shallowing to 15 and 6 meters.
The location of the blasting thus forms the last parallel point in greater depth. This detail can be interpreted in two ways: The location of the pipelines in shallow seabed could make repair too easy, or the depth was necessary to carry out the attack. Thematic maps show another characteristic feature: both scenes of the sabotage are located near international underwater cables. Less than two kilometers from the three leaks located northeast of Bornholm, the C-Lion runs parallel to and SWEPOL crosses the Nord Stream pipelines. Similarly, the leak that occurred on Nord Stream 2 southeast of Bornholm is only about 5 kilometers from the GK-22 submarine cable. In addition, other cables cross the pipeline at a distance of just under 20 to 25 kilometers.
The extent of the damage is so far illustrated by three private dives in the Swedish EEZ, while government investigations are subject to secrecy. On Oct. 18, 2022, footage published by the Swedish daily Expressen shows a destroyed section of Nordstream 1 at a depth of 76 meters, with a length of at least 50 meters, taken by an underwater drone from BlueEye Robotics on behalf of the newspaper. On November 2, 2022, Nord Stream AGreports that the company also “completed initial data gathering at the location of the pipeline damage on Line 1 in the Swedish exclusive economic zone… According to preliminary results of the damage site inspection, technogenic craters with a depth of 3-5 meters were found on the seabed at a distance of about 248 m from each other. The section of the pipe between the craters is destroyed, the radius of pipe fragments dispersion is at least 250 meters.” And finally, on November 30, it became known that Greenpeace had investigated the environmental damage with a diving robot. In doing so, the NGO was surprised to find that, despite the damage along a 250-meter length, only a few pieces of debris could be seen. However, it is likely that pieces may have been removed during the preceding governmental investigations, which are subject to secrecy.
Theories of sabotage
Early theories of sabotage included detonation by a “pig,” a remote-controlled cleaning robot inside the pipelines. Kenneth Buhl of the Danish Royal Defense College already spoke of an explosive charge being attached to the pipeline in Atlas News on September 27, 2022. Thorsten Pörschmann expressed himself in the same direction. The defense technology expert was an interview partner of Christian Rieck, a university professor of finance in Frankfurt, whose weekly YouTube broadcast on game theory attracts around a hundred thousand viewers and whose broadcast on the Nord Stream sabotage was accessed by some 1.4 million viewers.
In analyzing the Swedish footage, Pörschmann assumed submarines and laid ground mines because of the extensive destruction of the pipeline. The most recent theory on the blast was provided by Pulitzer Prize winner Seymour Hersh. He brought into play C4 explosive devices attached to the pipelines by US Navy divers, which were later triggered by sonar buoys.
The mystery of the differently sized gas bubbles
A widely brushed aside oddity is formed by the immensely differing radius of the escaping gas plumes. According to a joint letter from Denmark and Sweden to the UN Security Council dated September 29, 2022, the blast impact developed a force that caused a radius of the plumes on the surface of the sea to 555 and 680 meters in the Danish EEZ and about 900 and 200 meters in the Swedish EEZ. From the magnitudes and dimensions of the gas leak, the letter concluded that the explosive charges were “probably corresponding to an explosive load of several hundred kilos.” Another estimate, published by Der Spiegel and said to be based on German security sources, suggested 500 kilograms of TNT equivalent per leak. NORSAR, in turn, gave the first detonation as having a TNT equivalent of 190-320 kilograms and the second as having a force of 650-900 kilograms. What is striking about the sabotage is that although two of the four leaks affected Nord Stream 2, only strand A was blasted in two locations within 17 hours. Moreover, if one considers the size of the gas bubbles, it is also worthwhile to point out that one of the Nord Stream 2 leaks was only slightly more than one-fifth the size of the largest leak in the sabotage.
The explosives were probably detonated by means of a trigger, which blurred the temporal connection of the placement of the explosive charge and also allowed the saboteurs to leave the scene undetected. According to open sources, it is also unclear what means the saboteurs used to transport the explosives to the pipeline pipes, especially since at the moment – apart from Seymour Hersh’s unproven assertion – no information is made public about the explosives used and their actual weight. Experts speak of the use of (mini)submarines, remote-controlled underwater drones, a fishing vessel, or a warship as a base for the deployment of special forces.
Conclusion
In summary, it is generally assumed that a state actor was the perpetrator. Through Björn Lund we know that there were three blasts detected by the seismic networks. One southeast of Bornholm and two northeast of Bornholm. But there were four (1+3) leaks detected by the Naval Administrations. The location of the three leaks northeast of Bornholm has a peculiarity: they form the termination of the parallel pipeline in deep waters.
The different radii of the gas plumes indicate that different quantities of explosives were used – or – that the explosives were positioned differently close to the pipelines. In any case, the fact that only one of the two Nord Stream 2 pipes was blasted makes one wonder. More specifically, it raises three questions: Was a technique used that did not allow for precise placement, was there sloppiness because of hurry, or was Nord Stream 2 intentionally spared?