On Nov. 20 2013, the Japan Maritime Self-Defense Force discovered a small islet near Nishinoshima volcano, Ogasawara Islands, Japan. The exact date of the initial eruption that spawned the islet is unknown, but a thermal anomaly was detected in the area in early November 2013. Fukashi Maeno and colleagues are investigating the creation of this islet, which on the day of its discovery was about 150 by 80 meters in size.