Underground nuclear tests are hard to detect. A new method can spot them 99% of the time

US Department of Energy via Wikimedia Mark Hoggard, Australian National UniversitySince the first detonation of an atomic bomb in 1945, more than 2,000 nuclear weapons tests have been conducted by eight countries: the United States, the Soviet Union, the United Kingdom, France, China, India, Pakistan and North Korea. Groups such as the Comprehensive Nuclear-Test-Ban Treaty Organization are constantly on the lookout for new tests. However, for reasons of safety and secrecy, modern nuclear tests are carried out underground – which makes them difficult to detect. Often, the only indication they have occurred is from the seismic waves they generate. In a paper published in Geophysical Journal International, my colleagues and I have developed a way to distinguish between underground nuclear tests and natural earthquakes with around 99% accuracy. Fallout The invention of nuclear weapons sparked an international arms race, as the Soviet Union, the UK and France developed and tested increasingly larger and more sophisticated devices in an attempt to keep up with the US. Many early tests caused serious environmental and societal damage. For example, the US’s 1954 Castle Bravo test, conducted in secret at Bikini Atoll in the Marshall Islands, delivered large volumes of radioactive fallout to several nearby islands and their inhabitants. Between...

Read More........→February 21, 2024

Earthquake footage shows Turkey’s buildings collapsing like pancakes. An expert explains why

 Mustafa Karali / AP Mark Quigley, The University of MelbourneA pair of huge earthquakes have struck in Turkey, leaving more than 3,000 people dead and unknown numbers injured or displaced.The first quake, near Gaziantep close to the Syrian border, measured 7.8 in magnitude and was felt as far away as the UK. The second occurred nine hours later, on what appears to be an intersecting fault, registering a magnitude of 7.5.Adding to the devastation, some 3,450 buildings have collapsed, according to the Turkish government. Many of the modern buildings have failed in a “pancake mode” of structural collapse.Why did this happen? Was it simply the enormous magnitude and violence of the quake, or is the problem with the buildings?Thousands of years of earthquakesEarthquakes are common in Turkey, which sits in a very seismically active region where three tectonic plates constantly grind against one another beneath Earth’s surface. Historical records of earthquakes in the region go back at least 2,000 years, to a quake in 17 CE that levelled a dozen towns.The East Anatolian Fault zone that hosted these earthquakes is at the boundary between the Arabian and Anatolian tectonic plates, which move past each other at approximately 6 to 10 mm per year. The elastic strain that accumulates in this plate boundary zone is released by intermittent...

Read More........→February 08, 2023