Melanie's Blog

     Throughout the land, including islands, of South Korea there are three holocene volcanoes. Hallasan , located on Jeju island, Ulleungdo, located in the East Sea and is an island volcano, and Seongsan Ilchulbong, also located on Jeju island. There is also a fourth volcano, Chugaryong , but that volcano is located between North and South Korea and not much information is said about that one and is also in a demilitarized zone.  The last volcanic eruption in South Korea was in 1007 CE and was caused by the Hallasan volcano on Jeju island. Ulleungdo volcano last erupted in 2990 BCE and Seongsan Ilchulbong is said to have last erupted between 5,000 to 6,000 years ago. The tallest volcano being Hallasan, reaching up to 6,398 ft and is considered a shield volcano. None of South Korea's volcanoes are currently active and don't create a risk for Koreans. https://volcano.si.edu/volcanolist_countries.cfm?country=South%20Korea# https://www.volcanocafe.org/korean-volcanics-...

Since South Korea is located in a less seismically active region earthquakes are not as common, but this doesn't mean that they are free from ever experiencing them. Despite being on the Eurasian plate South Korea is located far away from active plate boundaries which is able to reduce the regularity of earthquakes.  The second largest earthquake to happen in modern South Korea occurred in 2017 with a magnitude of 5.5 and happened in Pohang. The Pohang earthquake unfortunately injured 90 people and caused $52 million in damage. Pohang is known to be in an area where an earthquake may less likely occur. But the reason why the event happened wasn't exactly caused by nature itself. It was caused by the operations of an enhanced geothermal system project. Their plan was to harvest energy by injecting high-pressure water into the subsurface. Apparently, the high-pressure water injection activated a previously unknown fault line which led to the earthquake. The first largest earthqua...