Disturbing the Ring of Fire

Tom Vance first became aware of the Ring of Fire volcanic area of the Pacific region as a high school geology student. Now after graduating from Stanford with a degree in geology, he is working at the US Embassy in Seoul, South Korea, in a newly-created position leading a department tasked with monitoring the underground plates that comprise the Ring of Fire.
Rachel Collins, a South Korean geologist, is Tom's right-hand person. Together they have traveled to other countries around South Korea to set up an extensive network of earthquake and tsunami-monitoring devices. When a catastrophic earthquake suddenly rocks Japan, Tom, Rachel, and their team immediately head to Okuma where they witness the devastating results. As Tom and Rachel fall in love, he begins exploring whether outside sources may have played a part in the event. Together with Rachel and the team, he sets out on a quest to learn whether North Korea's underground nuclear testing is causing the earthquakes, and if so, how they can stop it from happening again.
In this fascinating tale, an American geologist and his team investigate the source of devastating earthquakes with the hope that the region around the Ring of Fire may ultimately realize peace and prosperity.