Hi Reddit, The International Ocean Discovery Program (IODP) conducts scientific ocean drilling expeditions throughout the world’s oceans in search of clues to Earth’s structure and past. The current expedition is Expedition 362: Sumatra Seismogenic Zone, aboard the U.S. vessel for scientific ocean drilling, the JOIDES Resolution http://www.joidesresolution.org. We want to know why earthquakes happen where and when they do. When earthquakes happen in the ocean, they can displace huge volumes of water and cause tsunamis, such as the 26 December 2004 Sumatra earthquake and the 11 March 2011 Tohoku-Oki (Fukushima) earthquake. The combination of ground shaking and flooding is destructive and deadly. Very large earthquakes like these are typically at subduction zones , places where tectonic plates converge and one plate gets pushed down beneath the other. Yet these earthquakes, as well as several others in the past 15 years, surprised earth scientists in terms of their size and the amount and location of the fault slip during the earthquake. Subduction zone earthquakes can happen many tens or even hundreds of kilometers below Earth’s surface. The shallower and larger the earthquake, the more damage it can cause by shaking. It is even more dangerous if it occurs under the ocean floor because it can trigger a tsunami. We can’t predict earthquakes, but we can learn more about what happens below the Earth’s surface and why rocks break and cause earthquakes that trigger tsunamis. A team of 30 scientists from around the globe are on board for two months to work on these questions. Hand-in-hand with the amazing technology required to drill deep into the ocean floor, we are collecting the core samples that hold clues to answer these questions. We will be back at 12 pm ET, Join us to ask us anything about this intriguing science, how we got here, what we hope to discover, and our lives on board the ship! AMA!