X-Ray Earth reveals a vast fault 80 miles off the Pacific Northwest coast. For more than 300 years, pressure has been silently building. When it slips, it will generate a megaquake and a tsunami that will devastate the region, threatening the lives of 15 million residents. Now scientists are racing to understand how bad the destruction will be when the "big one" hits.

Originally released by National Geographic, 2020. Streaming video file encoded with permission for digital streaming by Infobase on January 05, 2023.