How Does the World Learn About a Nuclear Test?

Following Iran's missile attack on Israel, and while the global community awaited Israel's response, on the evening of October 6, social media users reported an earthquake in northern Iran. Shortly after, Iranian and international seismic centers reported a 4.5 magnitude earthquake in Semnan. This event fueled speculation about Iran's potential nuclear test and prompted the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), based in Vienna, to issue a statement on October 16, indicating that their investigations showed the recorded tremors matched previous earthquakes in the region. How does this organization analyze such information? Is Iran under increased scrutiny in this regard? And fundamentally, how does the world become aware of countries' nuclear testing activities? These are questions that Radio Farda discussed with Robert Floyd, the Executive Secretary of the CTBTO. Mr. Floyd, I would like to start from October 7 (October 16), when the CTBTO announced that it had analyzed data from the earthquakes in Iran and found that the signals matched previous earthquakes in northern Iran. Can you explain how your organization conducts this analysis and how you reached this conclusion? The CTBTO is responsible for establishing a verification system for the global commitment to the prohibition of nuclear tests. This verification system, an international monitoring system, consists of over 300 monitoring stations worldwide, many of which are seismic stations that detect vibrations in the Earth's crust. However, it is specifically designed to detect a nuclear explosion and distinguish it from any earthquake or other event. Thus, our system is specifically targeted for this purpose. One way we can determine whether this is a nuclear event or just a natural event is by comparing it with other natural events, such as other earthquakes that may occur in the same area of a country. And this is precisely what our analysts have done regarding northern Iran. So, whenever a movement occurs in the ground, such as a tremor in Iran or anywhere else in the world, does your organization analyze those tremors? It is indeed a bit more complex. The goal of our system is to detect a nuclear explosion. The Earth is a very noisy place. The ground is always moving and pressing against each other in various ways. We then have to identify potential signs of a nuclear explosion amid that noise. Therefore, we do not analyze every earthquake that occurs. They are generally reviewed because we are looking for events that are human-made that could be a nuclear explosion. Does this mean that some parts of the world, for example, countries that have nuclear weapons, are under more scrutiny than others? No, it is not. The design of our international monitoring system aims to identify a nuclear explosion anywhere on Earth that has a yield of one kiloton, equivalent to a thousand TNT. Therefore, regarding location, national borders or anything else does not matter. To better understand a kiloton and the sensitivity of our system, I should say that the bomb used in Hiroshima was 15 kilotons. In fact, our system can now detect a half-kiloton explosion anywhere on the planet. And all of this is about the actual testing of a nuclear weapon, not, for example, simulations that some countries may conduct to test their technology? That's correct. The Comprehensive Nuclear-Test-Ban Treaty prohibits nuclear explosions, and that is what we are monitoring, to see if there is any evidence of cheating, any violations of the treaty's commitments not to conduct nuclear explosions in any country's territory. We do not prohibit simulations; we prohibit nuclear explosions. Given the current situation in Iran, I would like to know if your organization has taken any specific actions. Because we know that Iran is enriching uranium at higher levels. There is much speculation about whether Iran will eventually build a nuclear weapon. Are you using any specific form of monitoring for Iran at this stage? Iran is one of the signatories of the Comprehensive Nuclear-Test-Ban Treaty. And as a signatory, it is committed to the subject and purpose of the treaty. We encourage all 187 signatory countries to adhere to the commitments they made when signing this treaty. The situation is the same for all countries. Our detection system has no relation to national borders. It simply looks at every square kilometer of this planet to determine if there are signs of a nuclear explosion anywhere. And we continue to cover the entire Earth 24 hours a day, seven days a week. It is remarkable that until September 24, 1996, when the Comprehensive Nuclear-Test-Ban Treaty was first prepared for signature, over two thousand nuclear tests had been conducted. However, since that date, about 28 years ago, to this day, fewer than 12 tests have been conducted in this century by only one country. I think the CTBTO is very successful. When you detect a nuclear test, what do you do? Who do you report it to? We report to the signatories of the treaty. They are our member countries. And if an event occurs, a seismic event or evidence we have indicating that a nuclear explosion has taken place, then we will urgently inform the signatories of the treaty, meaning all 187 members. For example, when North Korea tested a nuclear weapon, you acted this way, right? Yes. In this current century, we have only had North Korea's nuclear tests. Our system identified all nuclear tests in North Korea. This includes the first one, which was very small. But our system detected it. The North Korean regime also later acknowledged that it had conducted nuclear tests on each of those occasions, and when we first saw signs that there might be a nuclear test, we went through a process to fully inform our members, and our analysis clearly indicated what had actually happened. Given that you have only had the North Korean case in the 21st century, do you think this nuclear test ban, this treaty, is an appropriate tool? Are you satisfied with how the treaty is being implemented? I think it is remarkable that until September 24, 1996, when the Comprehensive Nuclear-Test-Ban Treaty was first prepared for signature, over two thousand nuclear tests had been conducted. However, since that date, about 28 years ago, to this day, fewer than 12 tests have been conducted in this century by only one country. I think it is very successful. There is a global norm against testing, and countries that have nuclear weapons have committed to stopping tests. They will not test. They have made this commitment. This brings peace and security for all humanity, even at this stage.