Estimating the Size of a Crater after an Underwater Explosion

Abstract

There have been terrorist attacks in the Baltic region that used explosives to destroy underwater infrastructure, including the Nord Stream 1 and 2 gas pipelines. Data from the Danish National Seismic Network indicate that two explosions occurred on 26 Sept 2022, causing gas leaks from pipelines. While examining the data from 26 Sept, two disturbing events were observed in the Baltic Sea, which caused tremors of magnitude 2.3 and 2.1 on the Richter scale. Both events had high wave energy, indicating an explosion, not an earthquake. Based on the above data, it was decided to analyze the potential effects of underwater explosions in the area of the Nord Stream gas pipelines. From the point of view of ecology, the volume of material torn up from the bottom is essential. For this purpose, empirical formulas for explosions on land were used, and then the crater's size was estimated per the physics of the underwater explosion phenomenon. Calculations indicate that the explosion of 750 kg of TNT will raise about 20 m 3 of the bottom volume into the water column. Because of the explosion, a gas bubble will form directly at the bottom, and it will suck the sand and the impurities contained in it and particles of dead organisms, bringing them to the surface and dispersing them in the water column. These attacks pose a severe environmental and safety risk as gas leaks from pipelines can cause harmful effects on marine ecosystems and people. It also violates international law and international agreements, including the United Nations Convention on the Law of the Sea and the Convention on the Protection of the Marine Environment in the Baltic Sea Region.