Tehran. On March 3, 2026, an earthquake of 4.3 magnitude occurred in the Khonj area of Fars province in Iran, whose epicenter was at a depth of 10 kilometers. According to the US Geological Survey (USGS), the earthquake occurred 52 kilometers northwest of Gerash city. Some reports are claiming that this earthquake was caused by Iran’s secret nuclear test, but experts rejected these claims. A report states that there is no scientific evidence between this earthquake and any nuclear or military activity.
Nuclear testing can cause earthquakes but its waves and characteristics are different from natural earthquakes. The intensity of an earthquake caused by a nuclear explosion depends on its power, such as a 5 megaton test can produce an earthquake of 6.9 magnitude but it also depends on the depth of the test.
The test is carried out at a sufficient depth for concealment, such as the Scaled Depth of Burial (SDBO) should be more than 100 meters per kiloton so that radioactive substances do not come out. The intensity of a typical nuclear test is 5 to 6 or higher on the Richter scale, with smaller tests resulting in lower intensities.
Iran’s most recent earthquake was just 4.3, which is low even for a small test. According to CTBTO, the waves of nuclear testing are explosive whereas those of natural earthquake are tectonic. North Korea’s 2016 test produced a 5.1-magnitude earthquake, equivalent to 7,000 tons of TNT, according to a lab. If the test is conducted at a shallower depth, the intensity is higher but the risk of radiation leaks increases.
Iran did not make any such direct claim a few days ago, but US Special Envoy Steve Witkoff said that Iran said that they have 460 kilograms of 60 percent enriched uranium, which is enough to make 11 nuclear bombs.
Mohammad-Javad Larijani, a close associate of Iran’s supreme leader, said Iran could develop military nuclear capability within 24 hours if needed. The report said that Iran has come close to making nuclear weapons but is not yet making them.