Some scientists discovered the historical and scientific evidence for a megathrust earthquake that generated a tsunami along the Cascadian subduction zone in 1700. A few geologists used radiocarbon dating and found that at least 900 kilometers (560 miles) along the fault ruptured between 1960 and 1720 (National Geographic Society [NGS], 1996). In 1996, Japanese researchers showed North American colleagues a tsunami that struck Honshu Island in 1700 to geological reports at the Cascadia subduction zone (NGS, 1996). Besides, Japan has a documented dating back to the 1500s, according to the National Geographic Society (1996). As a result, Japanese researchers concluded the Cascadia earthquake must have occurred in the evening of Tuesday, January …show more content…
Research by Keller and Devecchio (2015) supports that scientists begin geologic investigations in North America to decide the magnitude of the earthquake and how it created a tsunami in Japan. A few scientists found burned logs and soils below a tsunami deposit sometime after 1600 (Keller and Devecchio 2015). The geologist used radiocarbon dating to find when the woods and other plant material in the soil were last alive, and the deposits showed evidence of subsidence at the time of the earthquake. As a result, the geologic evidence showed the length of rupture was 1,000 km (620 mi) long. Keller and Devecchio (2015) point out that scientists studied evidence from Japan, which consists historical tsunami descriptions, including the run-up height (3-16 ft) that took place in 1700. Also, Keller and Devecchio (2015) point out that the evidence helped scientists understand the arrival time of the tsunami in Japan, which help them to inferred that the tsunami originated at the Cascadia subduction zone about 9:00 pm on January 26, 1700. The M9 earthquake generated a tsunami on the Cascadia subduction zone, which it took 12 hours for the tsunami to reach the shores of Japan (Keller and Devecchio