A new study has been published in Nature Geoscience (abstract) detailing how scientists correctly anticipated the location and strength of an earthquake earlier this year. On September 5th, a 7.6 earthquake rocked Costa Rica's Nicoya Peninsula. That region had seen earthquakes of (roughly) magnitude 7 in 1853, 1900, and 1950, so "geoscientists had forecast that a magnitude 7.7 to 7.8 quake should occur around the year 2000, plus or minus 20 years." "The Nicoya Peninsula is prone to earthquakes because it's an area of subduction, where the Cocos Plate is pushing underneath the Caribbean Plate, moving at a rate of about 8.5 centimeters per year. When regions such as this suddenly slip, they produce a megathrust earthquake. Most of the world's largest earthquakes — including the magnitude 9.0 Tohoku-Oki quake in Japan in 2011 and the magnitude 9.15 Sumatra-Andaman earthquake in 2004, both of which produced devastating tsunamis — fall into this category. .. The close study of this region allowed scientists to calculate how much strain was building in the fault and in May 2012 they published a study in which they identified two locked spots capable of producing an earthquake similar to the one in 1950. In September of that year, the landward patch ruptured and produced the earthquake. The offshore one is still locked and capable of producing a substantial but smaller earthquake, an aftershock with a magnitude as high as 6.9, the researchers say."