The Kikai volcano, an underwater volcano off the coast of Japan, is showing signs of reactivation after 7,300 years of dormancy. It last erupted in one of the largest explosions in geological history, forming a caldera that is now slowly refilling with magma, a process that has been ongoing for about 3,900 years. Recent observations, including steam emissions and small earthquakes, have raised concerns among scientists about the potential for another significant eruption. Yoshiyuki Tatsumi, a researcher, estimates a 1% chance of a catastrophic eruption within the next 100 years, which could lead to devastating consequences, including tsunamis affecting southern Japan, Taiwan, China, and even the Americas. The volcano is part of the Pacific Ring of Fire, where 90% of the world's earthquakes occur. Understanding the Kikai volcano's behavior may help scientists predict future eruptions and their impact on the environment.